"It’s not easy being green these days, as Kermit once put it. If the climate
crisis doesn’t get you down, then ‘drill baby drill’ surely will – plumbing the
depths, as it were, of sheer insanity.
"South America just achieved a remarkable energy milestone, quietly setting a
global benchmark: for the first time in history, the entire continent now has
zero new coal-fired power plants planned. To grasp how remarkable this is, we
"The traffic-laden Archway Road in north London is not where you’d expect to
find one of the UK’s most fascinating gardens. But venture down a side alley
off Highgate High Street and you’ll find a lush, curvaceous tangle where the
'BOULDER, Colo. — Proponents of a growing movement in the construction industry
are asking: Why tear down old buildings with wrecking balls when those
materials can be mined for reusable materials?
"Protected areas such as national parks, nature reserves and Indigenous lands
are the foundation of biodiversity conservation. However, climate change is
threatening their effectiveness in safeguarding wildlife, ecosystem services
A SWAY session by Joanne of Royal Far West School. http://sway.org.au/ via https://coviu.com/ SWAY is an oral language and literacy program based on Aboriginal knowledge, culture and stories. It has been developed by Educators, Aboriginal Education Officers and Speech Pathologists at the Royal Far West School in Manly, NSW.
"If you could walk the ocean floor off the coast of Cape Arago in Oregon in the
summer, you’d find yourself in the mysterious green depths of a forest of kelp.
Look up, and you’d see sunlight filtering through the fronds waving in the
"As federal agents rushed to arrest immigrants across Los Angeles, they
confined detainees – including families with small children – in a stuffy
office basement for days without sufficient food and water, according to
I’ve been thinking a bit about training at work recently, largely in the context of having spent the last twenty years working for US technology companies. I think effectively all of these companies made a pretty big mistake — they viewed training of employees as a perk much like vacation, book budgets, or t-shirts. They advertise their training programs as part of their recruitment process, and just like other perks they’re cut when times get a bit grim. However, that’s not actually why employers should train their people. We train people so that they have the skills they need to do their jobs — especially when things get real and aren’t working out to plan.
There are definitely industries who have good examples of this sort of risk reduction training done well — airlines and the military both engage in regular training activities that ensure that when things get exciting the people know what to do. This includes leaders being trained on how to make decisions that are likely to result in the desired outcomes.
However… High tech is not one of those places. I’ve seen a lot of tailored in-house training programs replaced by a corporate Udemy or LinkedIn Training subscription, and I have seen very little evidence that these all-you-can-eat e-learning platforms actually deliver much in terms of results. This is especially true because I am yet to meet an organization that gives their employees enough contiguous time to actually do one of these e-learning courses without doing it on their own time or with frequent context switches. I think what they do deliver is a training thing you can put on your HR site that has a fixed cost to the company.
I think its also true that individual employees should focus their self-funded training (if they do any, I suspect its rare) on skills that they find interesting or align with their longer term career goals. It is not the role of an individual to subsidize their employer.
When I rule the world (which is looking increasingly unlikely, but anyways), I think I’d start by identifying the skills a given team need to succeed — both in the base case of business as usual, but also in times of crisis. I’d stack rank those skills, and then I’d ensure that the team had at least a couple of examples of each skill. Perhaps the availability of a skill should be proportional to both the likelihood and impact of the risk if guards against? I wouldn’t be too concerned about the employment type of the people being trained either — if you seniors are contractors that’s not relevant, I still want my senior people to have the skills needed when they need them.
But I don’t rule the world. So I’ll just keep doing random learning things on my own time because they personally interest me, not because my employer of the day might one day need them.
Andy Pavlo of the CMU Database Group is well known for saying that while NoSQL databases acquire cyclical popularity, all databases eventually iterate back to a SQL interface — it happened with MongoDB and Google’s BigTable for example.
I think I have hit that point with etcd. Initially I ported from MySQL to etcd because I really wanted the inexpensive distributed locking and being able to watch values. However, I never actually watch values in my code any more, and I now spend a huge amount of my time maintaining what my code calls “caches”, but which I can now see are just poorly implemented secondary indexes. The straw that broke the camel’s back was https://github.com/etcd-io/etcd/issues/9043, which changed etcd’s defaults to only being able to return 1.5mb in a RPC request.
I therefore think it might be time for me to port back to a real SQL database, perhaps keeping etcd to manage distributed locks. Perhaps.
I need to think about this more to be honest, but I think I’ve hit the limit of what you can express in key / value pairs directly stored in etcd. I often want to look up items based off of a portion of their value (the values are JSON), but that’s not possible in etcd without maintaining those extra indices that I now maintain. As I’ve grown as a programmer, I now really really want the Chubby-style check-and-replace transactional multi-table update syntax that etcd offers and S3 recently introduced as well. So moving back to a pure SQL database would leave me missing that.
One alternative to ditching etcd entirely would be to write a RPC service which sat in front of it and abstracted away the underlying data store. If I treated etcd as a storage engine, and then maintained the various indices in that abstracting layer, then I might get to a happier place. This would map to how modern databases are build somewhat if we thought of the keys in etcd as page locations in a storage engine. etcd would be a quite expensive storage engine however given it’s in-memory only attributes.
Oh, and you should all go and watch Andy Pavlo’s excellent lectures on how to build a database storage engine:
Despite comments on my ikiwiki blog being fully moderated, spammers have
been increasingly posting link spam comments on my blog. While I used to use
the blogspam plugin, the
underlying service was likely retired circa
2017 and its public
repositories are all archived.
It turns out that there is a relatively simple way to drastically reduce the
amount of spam submitted to the moderation queue: ban the datacentre IP
addresses that spammers are using.
Looking up AS numbers
It all starts by looking at the IP address of a submitted comment:
From there, we can look it up using whois:
$ whois -r 2a0b:7140:1:1:5054:ff:fe66:85c5
% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://docs.db.ripe.net/terms-conditions.html
% Note: this output has been filtered.
% To receive output for a database update, use the "-B" flag.
% Information related to '2a0b:7140:1::/48'
% Abuse contact for '2a0b:7140:1::/48' is 'abuse@servinga.com'
inet6num: 2a0b:7140:1::/48
netname: EE-SERVINGA-2022083002
descr: servinga.com - Estonia
geoloc: 59.4424455 24.7442221
country: EE
org: ORG-SG262-RIPE
mnt-domains: HANNASKE-MNT
admin-c: CL8090-RIPE
tech-c: CL8090-RIPE
status: ASSIGNED
mnt-by: MNT-SERVINGA
created: 2020-02-18T11:12:49Z
last-modified: 2024-12-04T12:07:26Z
source: RIPE
% Information related to '2a0b:7140:1::/48AS207408'
route6: 2a0b:7140:1::/48
descr: servinga.com - Estonia
origin: AS207408
mnt-by: MNT-SERVINGA
created: 2020-02-18T11:18:11Z
last-modified: 2024-12-11T23:09:19Z
source: RIPE
% This query was served by the RIPE Database Query Service version 1.114 (SHETLAND)
Alternatively, you can use this WHOIS server with much better output:
$ whois -h whois.cymru.com -v 2a0b:7140:1:1:5054:ff:fe66:85c5
AS | IP | BGP Prefix | CC | Registry | Allocated | AS Name
207408 | 2a0b:7140:1:1:5054:ff:fe66:85c5 | 2a0b:7140:1::/48 | DE | ripencc | 2017-07-11 | SERVINGA-EE, DE
While I do want to eliminate this source of spam, I don't want to block
these datacentre IP addresses outright since legitimate users could be using
these servers as VPN endpoints or crawlers.
I therefore added the following to my Apache config to restrict the CGI
endpoint (used only for write operations such as commenting):
<Location /blog.cgi>
Include /etc/apache2/spammers.include
Options +ExecCGI
AddHandler cgi-script .cgi
</Location>
and then put the following in /etc/apache2/spammers.include:
<RequireAll>
Require all granted
# https://ipinfo.io/AS207408
Require not ip 46.11.183.0/24
Require not ip 80.77.25.0/24
Require not ip 194.76.227.0/24
Require not ip 2a0b:7140:1::/48
</RequireAll>
Finally, I can restart the website and commit my changes:
$ apache2ctl configtest && systemctl restart apache2.service
$ git commit -a -m "Ban all IP blocks from Servinga"
Future improvements
I will likely automate this process in the future, but at the moment my
blog can go for a week without a single spam message (down from dozens every
day). It's possible that I've already cut off the worst offenders.
I saw this document on running DeepSeek R1 [1] and decided to give it a go. I downloaded the llama.cpp source and compiled it and downloaded the 131G of data as described. Running it with the default options gave about 7 CPU cores in use. Changing the --threads parameter to 44 caused it to use 17 CPU cores (changing it to larger numbers like 80 made it drop to 2.5 cores). I used the --n-gpu-layers parameter with the value of 1 as I currently have a GPU with only 6G of RAM (AliExpress is delaying my delivery of a PCIe power adaptor for a better GPU). Running it like this makes the GPU take 12W more power than standby and using 5.5G of VRAM according to nvidia-smi so it is doing a small amount of work, but not much. The documentation refers to the DeepSeek R1 1.58bit model which I’m using as having 61 layers so presumably less than 2% of the work is done on the GPU.
Running like this it takes 2 hours of CPU time (just over 3 minutes of elapsed time at 17 cores) to give 8 words of output. I didn’t let any tests run long enough to give complete output.
The documentation claims that it will run on CPU with 20G of RAM. In my tests it takes between 161G and 195G of RAM to run depending on the number of threads. The documentation describes running on the CPU as “very slow” which presumably means 3 words per minute on a system with a pair of E5-2699A v4 CPUs and 256G of RAM.
When I try to use more than 44 threads I get output like “system_info: n_threads = 200 (n_threads_batch = 200) / 44” and it seems that I only have a few threads actually in use. Apparently there’s some issue with having more threads than the 44 CPU cores in the system.
I was expecting this to go badly and it met my expectations in that regard. But it was interesting to see exactly how it went badly. It seems that if I had a GPU with 24G of VRAM I’d still have 54/61 layers running on the CPU so even the largest of home GPUs probably wouldn’t make much difference.
Maybe if I configured the server to have hyper-threading enabled and 88 HT cores then I could have 88 threads and about 34 CPU cores in use which might help. But even if I got the output speed from 3 to 6 words per minute that still wouldn’t be very usable.
I’ve been off on a bit of a tangent recently. Its a slow burn tangent, that I am pretty sure was kicked off by this Geek Narrator podcast episode about the design of Turbo Puffer with Simon Eskildsen:
The basic idea is that you can build very large scale database systems using only the primitives provided by an object store such as Amazon S3. Now, the performance might also suck, but you can alleviate some of that with a good caching layer and in return you get massive scale. This first video caused me to discover the work of Andy Pavlo, who was interviewed by the same podcast:
Andy is hilarious, and then I had to go and watch the videos from his CMU Introduction to Databases course, which were excellent:
But none of this gets me to the point of being able to convince my friends that I am not insane. Perhaps sqlite adding support for this very thing will improve my credibility.
Honestly, I think there are a lot of interesting systems that can be built on top of an immutable object store such as S3, and that we should be talking more about that.
Let me catch you up on everything I’ve been working on in Hanami.
Over the first three months of this year, I’ve been pushing in three main areas:
Building a new unified website for Hanami, Dry RB and ROM
Developing new unified branding
Preparing for our sponsorship drive
Things have gone well on all fronts!
I built the site earlier this year. It’s functionally complete, though some docs and guides need still need to be ported over. The code is at hanami/site, and you can even click around a live preview (warning: no styles for now!). The fun part: our new site is a Hanami app! It was a real treat for me to be able to spend some time using Hanami when I put it together. There’s quite a few interesting implementation notes to share, but I’ll save them for another post (and in the meantime, you’re welcome to explore the code!).
The new site will be the first manifestation of our new unified branding for Hanami, Dry RB and ROM. We’re very lucky to have Aaron Moodie preparing this for us, and I’m so excited about how it’s shaping up!
Preparing for the sponsorship drive has been a big lift. This biggest part of preparing this to date has been writing—checks notes—one hojillion emails. I’ve now done everything I can on that front though, and I’m very pleased that we’ll soon be able to announce a range of founding patrons who’ll be joining Mike Perham in support of Hanami and the diverse future we want to build for Ruby.
Right now we’re hopefully a matter of weeks away from launching the sponsorship drive. I’ve been preparing updates to all the sites and getting a bunch of related content ready to go.
Aside from all of this, I’ve been preparing a new talk! Baltic Ruby is just a couple of months away. You all know I like to try different things with my talks, and this will be no exception. I think the direction may be a surprise, though. It will be both more personal and more expansive than ever.
On the code front, the biggest recent news is that the great Kyle Plump has been getting Hanami’s Rack 3 support ready. It is extremely gratifying that people like Kyle can pick up the slack in the project while I’ve had to focus on other areas.
That’s it for now. Stay tuned for what will hopefully be an exciting series of announcements in the next couple of months.
For the last couple of years I have been working on a SPICE protocol native proxy called Kerbside. The basic idea is to be able to provide SPICE Virtual Desktop Interface (VDI) consoles to users from cloud platforms such as Shaken Fist, OpenStack, or oVirt. Think Citrix, but for Open Source cloud platforms. SPICE is attractive here because it has some features that other more common VDI protocols like VNC don’t have — good cut and paste support, USB device pass-through, multiple monitor support, and so on. RDP has these, but RDP was not a supported VDI protocol when using qemu on Linux with KVM until incredibly recently — literally the last couple of months.
(In terms of clouds that Kerbside supports, I think it would be relatively trivial to also support Proxmox, KubeVirt, or a list of static manually created virtual machines, but there’s only so many things one Mikal can do at once…)
Some of these cloud platforms have supported SPICE consoles for a while, but generally with warts. OpenStack for example only exposes them as HTML5 transcoded sessions with reduced functionality. oVirt exposes them via a “proxy” which is just squid (or equivalent), but its fairly dumb — it exposes the underlying hypervisor details to the client for example. I thought I could do better than that.
The proxy itself has worked for a while. I haven’t eliminated the possibility that the proxy will need to be re-written in something more performant that Python, but Python is convenient for rapid prototyping and that’s a Future Mikal problem. The proxy is not perfect, but has been a lower priority while I landed supporting code in OpenStack. Now that OpenStack Epoxy (2025.1) includes most of the supporting code, its time to circle back to the proxy itself.
In the intervening time, the pinned requirements for Kerbside have bit rotted, so its time to take CI seriously so that I can have something like Renovate walk those dependencies forwards. I feel its important to have good CI before turning on something like Renovate, because otherwise how can you tell if the dependency version increment changes broke things?
But… CI testing for graphical consoles seems fiddly to me. I can do some naive things such as testing if I receive a SPICE protocol banner from the hypervisor via the proxy, but its not great. This is the approach taken with OpenStack Tempest testing for now, but its definitely a stop gap solution. To that end, I’ve been working an a simple command line SPICE client which will help me validate that a session works. However, that presents another layer of engineering to do… How do I provide an instance with well defined graphical console behavior?
Simply put, I want very defined behaviour for the instance being used as the test target. It should be small. It should boot quickly. It should never lock or blank the screen. It should have graphical output which makes it easy to determine a state change (for example when a key press occurs). Obviously, its time to write a UEFI binary to be the test target and not bother with an operating system at all. Its entirely a coincidence that I think UEFI binaries are quite interesting and have had them on the todo list for a while.
JFK did not say this thing.
Now, this YouTube playlist from the excellently named Queso Fuego is a nice introduction to UEFI programming, a thing I had not done before:
However, the punch line is that the bare minimum we need is a disk image with:
Protective Master Boot Record (MBR)
Primary and secondary GUID Partition Table (GPT) headers
Primary and secondary GPT partition entries
An EFI System Partition (ESP) formatted as FAT32 and containing a UEFI binary at /EFI/BOOT/BOOTX64.EFI
A Basic Data Partition (BSP) formatted as FAT32, but not requiring any content.
Luckily, Mr Fuego provides a tool which does all of this at https://github.com/queso-fuego/UEFI-GPT-image-creator which makes this part much easier. I’m not entirely sure that watching someone else write code is a great use of my time, but on the other hand if you don’t have anyone in your life that understands UEFI, it is a way to be walked through the topic — especially when the UEFI specification is over 2,300 pages long and the book I bought on the topic isn’t actually the most gripping reading. Overall I don’t regret watching the video series.
So that’s the disk image. Inside the partitions we’ll need a FAT32 file system, which is well described by Wikipedia and also handled by Mr Fuego’s tooling.
A previous
analysis
from 2019 found that many popular authenticators were happy to accept
parameters they didn't actually support and then generate the wrong codes.
At the time, a service wanting to offer TOTP to its users had to stick to
the default security parameters or face major interoperability issues with
common authenticator clients. Has the landscape changed or are we still
stuck with security decisions made 15 years
ago?
You should also avoid putting the secret parameter
last in the URI to avoid breaking
some versions of Google Authenticator which parse these URIs incorrectly.
Other security and user experience considerations:
Keep track of codes that are already used for as long they
are valid since these codes are meant to be one-time credentials.
Avoid storing the TOTP secret directly in plaintext inside the main app database
and instead store it in some kind of secrets manager. Note: it cannot be
hashed because the application needs the secret to generate the expected codes.
Provide a recovery mechanism since users will lose their
authenticators. This is often done through the use of one-time "scratch codes".
Consider including in generated URIs two parameters introduced by the best Android client: image
and
color.
Most clients will ignore them, but they also don't hurt.
I previously wrote a blog post Why Clusters Usually Don’t Work [2] and I believe that all the points there are valid today – and possibly exacerbated by clusters getting less direct use as clustering is increasingly being done by hyperscale providers.
Take a basic need, a MySQL or PostgreSQL database for example. You want it to run and basically do the job and to have good recovery options. You could set it up locally, run backups, test the backups, have a recovery plan for failures, maybe have a hot-spare server if it’s really important, have tests for backups and hot-spare server, etc. Then you could have documentation for this so if the person who set it up isn’t available when there’s a problem they will be able to find out what to do. But the hyperscale option is to just select a database in your provider and have all this just work. If the person who set it up isn’t available for recovery in the event of failure the company can just put out a job advert for “person with experience on cloud company X” and have them just immediately go to work on it.
I don’t like hyperscale providers as they are all monopolistic companies that do anti-competitive actions. Google should be broken up, Android development and the Play Store should be separated from Gmail etc which should be separated from search and adverts, and all of them should be separated from the GCP cloud service. Amazon should be broken up, running the Amazon store should be separated from selling items on the store, which should be separated from running a video on demand platform, and all of them should be separated from the AWS cloud. Microsoft should be broken up, OS development should be separated from application development all of that should be separated from cloud services (Teams and Office 365), and everything else should be separate from the Azure cloud system.
But the cloud providers offer real benefits at small scale. Running a MySQL or PostgreSQL database for local services is easy, it’s a simple apt command to install it and then it basically works. Doing backup and recovery isn’t so easy. One could say “just hire competent people” but if you do hire competent people do you want them running MySQL databases etc or have them just click on the “create mysql database” option on a cloud control panel and then move on to more important things?
The Debian packaging of Open Stack looks interesting [4], it’s a complete setup for running your own hyper scale cloud service. For medium and large organisations running Open Stack could be a good approach. But for small organisations it’s cheaper and easier to just use a cloud service to run things.
The issue of when to run things in-house and when to put them in the cloud is very complex. I think that if the organisation is going to spend less money on cloud services than on the salary of one sysadmin then it’s probably best to have things in the cloud. When cloud costs start to exceed the salary of one person who manages systems then having them spend the extra time and effort to run things locally starts making more sense. There is also an opportunity cost in having a good sysadmin work on the backups for all the different systems instead of letting the cloud provider just do it. Another possibility of course is to run things in-house on low end hardware and just deal with the occasional downtime to save money. Knowingly choosing less reliability to save money can be quite reasonable as long as you have considered the options and all the responsible people are involved in the discussion.
The one situation that I strongly oppose is having hyper scale services setup by people who don’t understand them. Running a database server on a cloud service because you don’t want to spend the time managing it is a reasonable choice in many situations. Running a database server on a cloud service because you don’t understand how to setup a database server is never a good choice. While the cloud services are quite resilient there are still ways of breaking the overall system if you don’t understand it. Also while it is quite possible for someone to know how to develop for databases including avoiding SQL injection etc but be unable to setup a database server that’s probably not going to be common, probably if someone can’t set it up (a generally easy task) then they can’t do the hard tasks of making it secure.
This approach of having 2 AI systems where one processes user input and the second performs actions on quarantined data is good and solves some real problems. But I think the bigger issue is the need to do this. Why not have a multi stage approach, instead of a single user input to do everything (the example given is “Can you send Bob the document he requested in our last meeting? Bob’s email and the document he asked for are in the meeting notes file”) you could have “get Bob’s email address from the meeting notes file” followed by “create a new email to that address” and “find the document” etc.
A major problem with many plans for ML systems is that they are based around automating relatively simple tasks. The example of sending an email based on meeting notes is a trivial task that’s done many times a day but for which expressing it verbally isn’t much faster than doing it the usual way. The usual way of doing such things (manually finding the email address from the meeting notes etc) can be accelerated without ML by having a “recent documents” access method that gets the notes, having the email address be a hot link to the email program (IE wordprocessor or note taking program being able to call the MUA), having a “put all data objects of type X into the clipboard (where X can be email address, URL, filename, or whatever), and maybe optimising the MUA UI. The problems that people are talking about solving via ML and treating everything as text to be arbitrarily parsed can in many cases by solved by having the programs dealing with the data know what they have and have support for calling system services accordingly.
The blog post suggests a problem of “user fatigue” from asking the user to confirm all actions, that is a real concern if the system is going to automate everything such that the user gives a verbal description of the problem and then says “yes” many times to confirm it. But if the user is at every step of the way pushing the process “take this email address” “attach this file” it won’t be a series of “yes” operations with a risk of saying “yes” once too often.
I think that one thing that should be investigated is better integration between services to allow working live on data. If in an online meeting someone says “I’ll work on task A please send me an email at the end of the meeting with all issues related to it” then you should be able to click on their email address in the meeting software to bring up the MUA to send a message and then just paste stuff in. The user could then not immediately send the message and clicking on the email address again would bring up the message in progress to allow adding to it (the behaviour of most MUAs of creating a new message for every click on a mailto:// URL is usually not what you desire). In this example you could of course use ALT-TAB or other methods to switch windows to the email, but imagine the situation of having 5 people in the meeting who are to be emailed about different things and that wouldn’t scale.
Another thing for the meeting example is that having a text chat for a video conference is a standard feature now and being able to directly message individuals is available in BBB and probably some other online meeting systems. It shouldn’t be hard to add a feature to BBB and similar programs to have each user receive an email at the end of the meeting with the contents of every DM chat they were involved in and have everyone in the meeting receive an emailed transcript of the public chat.
In conclusion I think that there are real issues with ML security and something like this technology is needed. But for most cases the best option is to just not have ML systems do such things. Also there is significant scope for improving the integration of various existing systems in a non-ML way.
I’ve just got a second hand Nissan LEAF. It’s not nearly as luxurious as the Genesis EV that I test drove [1]. It’s also just over 5 years old so it’s not as slick as the MG4 I test drove [2]. But the going rate for a LEAF of that age is $17,000 vs $35,000 or more for a new MG4 or $130,000+ for a Genesis. At this time the LEAF is the only EV in Australia that’s available on the second hand market in quantity. Apparently the cheapest new EV in Australia is a Great Wall one which is $32,000 and which had a wait list last time I checked, so $17,000 is a decent price if you want an electric car and aren’t interested in paying the price of a new car.
Starting the Car
One thing I don’t like about most recent cars (petrol as well as electric) is that they needlessly break traditions of car design. Inserting a key and turning it clockwise to start a car is a long standing tradition that shouldn’t be broken without a good reason. With the use of traditional keys you know that when a car has the key removed it can’t be operated, there’s no situation of the person with the key walking away and leaving the car driveable and there’s no possibility of the owner driving somewhere without the key and then being unable to start it. To start a LEAF you have to have the key fob device in range, hold down the brake pedal, and then press the power button. To turn on accessories you do the same but without holding down the brake pedal. They also have patterns of pushes, push twice to turn it on, push three times to turn it off. This is all a lot easier with a key where you can just rotate it as many clicks as needed.
The change of car design for the key means that no physical contact is needed to unlock the car. If someone stands by a car fiddling with the door lock it will get noticed which deters certain types of crime. If a potential thief can sit in a nearby car to try attack methods and only walk to the target vehicle once it’s unlocked it makes the crime a lot easier. Even if the electronic key is as secure as a physical key allowing attempts to unlock remotely weakens security. Reports on forums suggest that the electronic key is vulnerable to replay attacks. I guess I just have to hope that as car thieves typically get less than 10% of the value of a car it’s just not worth their effort to steal a $17,000 car. Unlocking doors remotely is a common feature that’s been around for a while but starting a car without a key being physically inserted is a new thing.
Other Features
The headlights turn on automatically when the car thinks that the level of ambient light warrants it. There is an option to override this to turn on lights but no option to force the lights to be off. So if you have your car in the “on” state while parked the headlights will be on even if you are parked and listening to the radio.
The LEAF has a bunch of luxury features which seem a bit ridiculous like seat warmers. It also has a heated steering wheel which has turned out to be a good option for me as I have problems with my hands getting cold. According to the My Nissan LEAF Forum the seat warmer uses a maximum of 50W per seat while the car heater uses a minimum of 250W [3]. So if there are one or two people in the car then significantly less power is used by just heating the seats and also keeping the car air cool reduces window fog.
The Bluetooth audio support works well. I’ve done hands free calls and used it for playing music from my phone. This is the first car I’ve owned with Bluetooth support. It also has line-in which might have had some use in 2019 but is becoming increasingly useless as phones with Bluetooth become more popular. It has support for two devices connecting via Bluetooth at the same time which could be handy if you wanted to watch movies on a laptop or tablet while waiting for someone.
The LEAF has some of the newer safety features, it tracks lane markers and notifies the driver via beeps and vibration if they stray from their lane. It also tries to read speed limit signs and display the last observed speed limit on the dash display. It also has a skid alert which in my experience goes off under hard acceleration when it’s not skidding but doesn’t go off if you lose grip when cornering. The features for detecting changing lanes when close to other cars and for emergency braking when another car is partly in the lane (even if moving out of the lane) don’t seem well tuned for Australian driving, the common trend on Australian roads is lawful-evil to use DND terminology.
Range
My most recent driving was just over 2 hours driving with a distance of a bit over 100Km which took the battery from 62% to 14%. So it looks like I can drive a bit over 200Km at an average speed of 50Km/h. I have been unable to find out the battery size for my car, my model will have either a 40KWh or 62KWh battery. Google results say it should be printed on the B pillar (it’s not) and that it can be deduced from the VIN (it can’t). I’m guessing that my car is the cheaper option which is supposed to do 240Km when new which means that a bit over 200Km at an average speed of 50Km/h when 6yo is about what’s expected. If it has the larger battery designed to do 340Km then doing 200Km in real use would be rather disappointing.
Assuming the battery is 40KWh that means it’s 5Km/KWh or 10KW average for the duration. That means that the 250W or so used by the car heater should only make a about 2% difference to range which is something that a human won’t usually notice. If I was to drive to another state I’d definitely avoid using the heater or airconditioner as an extra 4km could really matter when trying to find a place to charge when you aren’t familiar with the area. It’s also widely reported that the LEAF is less efficient at highway speeds which is an extra difficulty for that.
It seems that the LEAF just isn’t designed for interstate driving in Australia, it would be fine for driving between provinces of the Netherlands as it’s difficult to drive for 200km without leaving that country. Driving 700km to another city in a car with 200km range would mean charging 3 times along the way, that’s 2 hours of charging time when using fast chargers. This isn’t a problem at all as the average household in Australia has 1.8 cars and the battery electric vehicles only comprise 6.3% of the market. So if a household had a LEAF and a Prius they could just use the Prius for interstate driving. A recent Prius could drive from Melbourne to Canberra or Adelaide without refuelling on the way.
If I was driving to another state a couple of times a year I could rent an old fashioned car to do that and still be saving money when compared to buying petrol all the time.
Running Cost
Currently I’m paying about $0.28 per KWh for electricity, it’s reported that the efficiency of charging a LEAF is as low as 83% with the best efficiency when fast charging. I don’t own the fast charge hardware and don’t plan to install it as that would require getting a replacement of the connection to my home from the street, a new switchboard, and other expenses. So I expect I’ll be getting 83% efficiency when charging which means 48KWh for 200KM or 96KWH for the equivalent of a $110 tank of petrol. At $0.28/KWh it will cost $26 for the same amount of driving as $110 of petrol. I also anticipate saving money on service as there’s no need for engine oil changes and all the other maintenance of a petrol engine and regenerative braking will reduce the incidence of brake pad replacement.
I expect to save over $1100 per annum on using electricity instead of petrol even if I pay the full rate. But if I charge my car in the middle of the day when there is over supply and I don’t get paid for feeding electricity from my solar panels into the grid (as is common nowadays) it could be almost free to charge the car and I could save about $1500 on fuel.
Comfort
Electric cars are much quieter than cars with petrol or Diesel engines which is a major luxury feature. This car is also significantly newer than any other car I’ve driven much so it has features like Bluetooth audio which weren’t in other cars I’ve driven. When doing 100Km/h I can hear a lot of noise from the airflow, part of that would be due to the LEAF not having the extreme streamlining features that are associated with Teslas (such as retracting door handles) and part of that would be due to the car being older and the door seals not being as good as they were when new. It’s still a very quiet car with a very smooth ride. It would be nice if they used the quality of seals and soundproofing that VW uses in the Passat but I guess the car would be heavier and have a shorter range if they did that.
This car has less space for the driver than any other car I’ve driven (with the possible exception of a 1989 Ford Laser AKA Mazda 323). The front seats have less space than the Prius. Also the batteries seem to be under the front seats so there’s a bulge in the floor going slightly in front of the front seats when they are moved back which gives less space for the front passenger to move their legs and less space for the driver when sitting in a parked car. There are a selection of electric cars from MG, BYD, and Great Wall that have more space in the front seats, if those cars were on the second hand market I might have made a different choice but a second hand LEAF is the only option for a cheap electric car in Australia now.
The heated steering wheel and heated seats took a bit of getting used to but I have come to appreciate the steering wheel and the heated seats are a good way of extending the range of the car.
Misc Notes
The LEAF is a fun car to drive and being quiet is a luxury feature, it’s no different to other EVs in this regard. It isn’t nearly as fast as a Tesla, but is faster than most cars actually drive on the road.
When I was looking into buying a LEAF from one of the car sales sites I was looking at models less than 5 years old. But the ZR1 series went from 2017 to 2023 so there’s probably not much difference between a 2019 model and a 2021 model but there is a significant price difference. I didn’t deliberately choose a 2019 car, it was what a relative was selling at a time when I needed a new car. But knowing what I know now I’d probably look at that age of LEAF if choosing from the car sales sites.
Problems
When I turn the car off the side mirrors fold in but when I turn it on they usually don’t automatically unfold if I have anything connected to the cigarette lighter power port. This is a well known problem and documented on forums. This is something that Nissan really should have tested before release because phone chargers that connect to the car cigarette lighter port have been common for at least 6 years before my car was manufactured and at least 4 years before the ZE1 model was released.
The built in USB port doesn’t supply enough power to match the power use of a Galaxy Note 9 running Google maps and playing music through Bluetooth. On it’s own this isn’t a big deal but combined with the mirror issue of using a charger in the cigarette lighter port it’s a problem.
The cover over the charging ports doesn’t seem to lock easily enough, I had it come open when doing 100Km/h on a freeway. This wasn’t a big deal but as the cover opens in a suicide-door manner at a higher speed it could have broken off.
The word is that LEAF service in Australia is not done well. Why do you need regular service of an electric car anyway? For petrol and Diesel cars it’s engine oil replacement that makes it necessary to have regular service. Surely you can just drive it until either the brakes squeak or the tires seem worn.
I have been having problems charging, sometimes it will charge from ~20% to 100% in under 24 hours, sometimes in 14+ hours it only gets to 30%.
Conclusion
This is a good car and the going price on them is low. I generally recommend them as long as you aren’t really big and aren’t too worried about the poor security.
It’s a fun car to drive even with a few annoying things like the mirrors not automatically extending on start.
The older ones like this are cheap enough that they should be able to cover the entire purchase cost in 10 years by the savings from not buying petrol even if you don’t drive a lot. With a petrol car I use about 13 tanks of petrol a year so my driving is about half the average for Australia. Some people could cover the purchase price of a second hand leaf in under 5 years.
Meeting opened at 19:39 AEDT by Joel and quorum was achieved.
Minutes taken by Neill
2. Log of correspondence
Spreadsheet shared with you: “EOCBR2026 Draft Conference Budget” – EO2026 has shared a draft budget
LA Subcommittee Meeting Time Update – questions from Jack – no response yet
Westpac access to WP AUstralia account – Wil has asked for his access to the WP – Australia bank account be restored. Russell has dealt with this.
donation to Linux Australia – offer of funds from AAUG Vic as they wind up. Russell has responded.
Authorisation for Kiwi PyCon Transaction Exceeding $5000 – Russell has responded
Fwd: Add Authoriser to ANZ Direct Online – 417289 Linux Australia (Incorporated)
Re: WordCamp Brisbane 2025: venue documents & sponsorship prospectus – long discussion between WordPress Community and Wordcamp Brisbane. Ending with a question for Russell
Funding for WordCamp Brisbane – email from Joel clarifying seed funding for WordCamp Brisbane. No further action.
Pls sign petition at https://codeberg.org/OSI-Concerns/election-results-2025 as an Affiliate – Bradley Kuhn asking for LA to sign a petition re alleged irregularities in the OSI election. See items for discussion below.
[LACTTE] Fwd: WordCamp Brisbane Request – request from WordPress Community for LA to cover some initial costs for WordCamp Brisbane. This has been dealt with.
Re: Mandate update – Linux Australia – Attn Kush – request for new people to be added to LA ANZ NZ account. ANZ have requested a signed minutes or resolution authorising the addition. See items for discussion below.
Authorisation for Kiwi PyCon Transaction Exceeding $5000 (2025-04-28 Venue Installment #2) – Russell has responded
Request for LA to contribute to Fosstodon.org at $AUD 9 per month level via Patreon – Kathy Reid has requested LA sponsor Fosstodon
You’ve Made A Sale – 73722237 (US$0.40) – this may be the smallest sale we have ever made on RedBubble.
PyCon AU 2025 subcommittee establishment – Russell has responded (Also a request for seed money ended up in this thread)
Manufacturing Statement – 73722237 – from RedBubble for one sticker
Amazon Web Services Billing Statement Available [Account: 103334912252]
PyCon Au Venue Deposit – Request for approval for the venue deposit for PyCon Au 2025 – Joel has responded
Letter to Linux Australia Inc. 11.12.24 – Clayton Utz have responded, withdrawing their copyright claim and apologising. Thank you Russell!
Activity statements are available online [SEC=OFFICIAL:Sensitive] – notification from the ATO that activity statements are due by 26 May. This has been dealt with.
[Important End Of Support Notification] Zoom Rooms Control System API (ZR CSAPI) – deprecation notice from Zoom. No action required.
3. Items for discussion
MOTION: Linux Australia shall open 3 new westpac.com.au bank accounts capable of paying via bank transfer, international bank transfer and BPay.
PROPOSER: Russell Stuart
SECONDER: Neill Cox
OUTCOME: Motion passed
MOTION: Linux Australia shall add the following people to the mandate for its anz.co.nz bank accounts, and enable them to be payment authorisers on some accounts: Chelsea Finnie, Elena Williams, Hoi Sze (Lilly) Ho, Jennifer Cox and Neill Cox.
PROPOSER: Russell Stuart
SECONDER: Jonathan Woithe
OUTCOME: Motion passed
MOTION: Linux Australia establishes the Session Selection Committee for EO2026 with Sae Ra Germaine and Donna Benjamin as chairs.
PROPOSER: Joel Addison
SECONDER: Jennifer Cox
OUTCOME: Motion passed
Purplecon 2025
We should call a meeting with them to discuss their budget, which is currently a problem as it shows losses. We need to explain that they need to provide a realistic budget that expects to turn a small profit.
Support for Fosstodon
Motion: That Linux Australia provides financial support for our use of Fosstodon in the amount of AUD 108 per year.
Proposer: Neill Cox
Seconder: Joel Addison
Outcome: Motion passed
OSI Election
Motion: That Linux Australia signs the petition raised by Bradley Kuhn at https://codeberg.org/OSI-Concerns/election-results-2025
Moved: Russell Stuart
Seconded: Jonathan Woithe
Outcome: Motion defeatedNote: Individual members of both the council and LA generally are encouraged to sign the petition if they desire. Council has concerns about how these elections were run, but do not want to take a position as an organisation.
4. Items for noting
We need to update the Subcommittee policy to be accurate, and also make sure that everyone on a Subcommittee is a member.
Need to respond to WP Community after checking with Wil to make sure we can share the budget information they have requested. Particularly if they want a full list of transactions. Russell will respond (Russell thinks this is up to WC Brisbane to decide]
5. Other business
Membership applicationsThere are currently 150 membership applications pending approval. Of these 91 are from before 2024 and I suggest we either reject them or ask people to re-apply.Membership Applications – 2025-05-07
For all membership applications we want to see some involvement from prospective members. We will update the membership application form to collect this for new applications. For existing pending ones we will ask via email.
PyNZ seeking donations/sponsorship via a 3rd party
Will sponsors be happy knowing 20% of their donation went toward paying someone?
What guarantees for the proper handling of personal details?
What about the incentive to the 3rd party to focus on quantity over qualityLA is not likely to support this unless PyNZ can provide assurances that this will be done well. LA recognises the difficulties that conferences face in finding sponsors, but we must prioritise our reputation when considering this approach.
6. In camera
None
7. Action items
Neill: respond to Jack re subcommittee membership requirements and meetings.
Russell: respond to WP Community after discussing with Wil
Neill to respond to Kathy re Fosstodon
Russell: Arrange a meeting between PurpleCon organisers, Russell and Elena
Joel: Arrange a meeting with Drupal South to discuss funding arrangements
Neill: Codify our membership policy
All: Update the membership application form to collect evidence of involvement in the community
7.1 Completed Items
7.2 Carried Forward
Meeting closed at 20:49
Next meeting is scheduled for 2025-05-21 and is a subcommittee meeting
Meeting opened at 08:02 AEDT by Jenny and quorum was achieved.
Minutes taken by Neill
2. Log of correspondence
2025-02-15 Re: [LACTTE] Is it time to shut down the HH LA Subcommittee? – Jonathan has responded
2025-02-01 – NSW Fair Trading Annual Return has been submitted – by Russell
2025-02-01 – Fwd: [APNIC #5872438][LINUXAUS-AU] – APNIC Membership Renewal – Invoice Attached – Russell has responded
2025-02-03 – Tax Invoice #1797722 – Please Do Not Reply – Invoice for renewal of opensource.org.au domain
2025-02-03 – Domain renewal prices – Question to the admin team about reconciling domain renewal prices and invoices.
2025-02-03 – Westpac Authorisation Changes – Discussion between Russell and Joel about updating Westpac users
2025-02-02 – Amazon Web Services Billing Statement Available [Account: 103334912252]
2025-02-03 – Fwd: confirm 5eb0dcf9acbc751ef8de9b6d6ed48d50f2f79c83 – Wil Brown notifying council that the unsubscribe function for some LA lists use http instead of https – Joel and Steve have responded
2025-02-03 – Expenditure Request – Stickers – request from Sae Rae for funds to print stickers for the Melbourne DDD Conference – responses from Jenny and Jonathan
2025-02-04 – Linux Australia Induction – Arranging an induction for new council members
2025-02-06 – Get ready to vote for OSI’s board of directors in 2025 – notification about upcoming elections
2025-02-09 – Upcoming Domain Renewal Notice – Please Do Not Reply – renewal notification for opensource.org.au
2025-02-09 – Thank You for Your Payment – Please Do Not Reply – receipt for renewal of opensource.org.au
2025-02-12 – Job ads for linux tech – request to post a job ad – Neill has responded
2025-02-15 – Upcoming Domain Renewal Notice – Please Do Not Reply – Another renewal notification (?)
2025-02-15 – Upcoming changes to Bitly’s Terms of Service – Bitly is going to start inserting ads into their free service
2025-02-15 – MoU between WCS and LA for WordCamps – Wil Brown points out that we need to address distribution of profits in the MoU – Joel has responded. The matter does not seem to be resolved yet
2025-02-15 – That secret number – Miles Goodhew confirming his control of the eocbr2026@gmail.com account
2025-02-15 – Everything Open 2026 bid for Canberra – updates from Miles Goodhew about progress of the EO2026 bid and a request for last years budget
2025-02-17 (and other dates) – You’ve made a sale – …. – several notifications from Redbubble about sales
2025-02-17 – [LACTTE] ASIC Form 490 has been submitted – Russell has submitted the required notification to ASIC about the changes in council membership.
2025-02-17 – OSI Board nominations: last day – Notification that nominations for the OSI board are closing
2025-02-19 – Invitation to OSI Affiliates Town Hall – Notification from OSI
2025-02-19 – we received two calendar invites to an OSI Town Hall
2025-02-20 – Payment for your PO Box is due soon – Notification from Australia Post that we need to renew or PO Box before 2025-03-31
2025-02-21 – Participate in our small business survey – Invitation from the NSW Small Business Commissioner to participate in a survey
2025-02-23 – [LACTTE] Social media from DDDMelbourne yesterday for sharing – Kathy Reid informing us of social media posts about DDD – Joel has responded
2025-02-25 – Incorrect PO Box renewal fee – Australia Post notifies us that they made a mistake in their last email
2025-02-25 – Purchase Approval Request DrupalSouth Schwag Fwd: Invoice INV-54994 from PROMOTION PRODUCTS PTY LTD for DrupalSouth c/o Linux Australia Inc. – Request for payment of invoices for Drupal South – [I believe Russel has deal with these – confirm?]
2025-02-25 – Fwd: EO2026CBR Schedule – Miles Goodhew has sent us the proposed schedule for organising EO2026
2025-02-26 – Re: Re ID of Organisation with Westpac – Correspondence between Russell and Westpac about arranging ID for a NZ resident.
Current profit 5235 vs target of 15k. Definite improvement since January
Currently 13 paid sponsors.4 Unpaid (being chased)
Challenges: experiment with a new client seminar – invite only for key sponsors and contributors to talk about emerging trends. There hasn’t been much interest, so the committee is now coming up with a backup plan.
Perhaps LA could help promote it on social media.
Will make a call by the end of next week as to whether to continue
Switching bank accounts makes life a little difficult – government departments in particular struggle with bank account changes.
Getting a Westpac Australia account is difficult for a NZ resident
Key achievements: Uptick on financial recovery compared to last year
Would like to see more income coming from sponsorship in future
LA Help: Increased promotional support – mailing list / mastodon / budgetary advice
Drupal South may run in NZ next year. They have a list of venues
Russell: Bank account – auditor says we have too many bank accounts. More bank accounts means increased work on treasure and auditorIf necessary we can move transactions from one account to another (for example for government departments payments – would be a problem if it was a lot of transactions but a few won’t be a problem)
DrupalCon Singapore Subcommittee
Singapore update:
A huge success all came together in the end
253 attendees from 35 countries
The contribution day (sprints) had to turn many people away – much higher participation rate.
No negative feedback from post event survey
The food was so good that someone crashed the event.
Some late bills have come in, but the event still made a profit.
The council recognises the effort put in by the organisers to turn around what was looking like a bad financial situation.
Japan:
Nara November 17-19
29% of all new Drupal developers are in Japan
Large participation in Singapore from Japan (10% of total attendees – many self funded)
Good support from Nara, both government and community.
Large population (20 million) to draw from
Looking to keep the price down for the conference – Nara is much cheaper than Tokyo would be.
Have found a venue which seems well suited and relatively cheap with good accommodation options.
There is a backup venue in Chiba (near Tokyo)
Budget is for 200 to 300 people – confident that they can at least match the Singapore numbers.
30K likely 67k very likely 41k ready to sign – no refusals, but some no responses. Min target 167k
Plan to run the conference budget in AUD, except for ticket sales. This will hopefully avoid some tax complications.
No video recording unless they meet the medium budget.
Drupal Association has committed to two more events with Linux Australia and will then re-evaluate.
Without LA’s support the only other option would be to engage a private company to run the event.
India is the next target location. Will be very different.
Russell: Are Autommattic likely to return?
Answer: Apparently they are keen to return.
Russell: We seem to need to register if we make >100K ticket sales from Japanese attendees, but this needs to be clarified.
Answer: No way we will hit that number. May be problematic to actually turn away Japanese attendees, but perhaps we can find other ways.
Elena: Will visas be an issue?
Answer: Expectation is that it will be similar to SIngapore – attendees from India, Pakistan and Indonesia may need a letter from the event. Others should b fine
Would like to make an announcement on 29 March at DrupalCon Atlanta and open ticket sales at the same time.
Kiwi PyCon / Python NZ (Chelsea and Danny)
Budget has been submitted – Neill found it all a little confusing.
Russell hasn’t been able to review the budget properly – will do so in the next few days.
Chelsea says the budget is quite pessimistic. Has the possibility of reducing catering costs if necessary.
Decision needed as soon as possible. Any delays may affect sponsorship. Two weeks is a problem. Council will try and address it sooner.
Joomla (Nathan)
Budget status (if applicable): Not currently planning an in person event, focussing on completing the sub-committee setup.
Key achievements since last update:Notified last Joomla user group meeting on 11th of February that nominations for subcommittee positions were open.
A timeline for elections to be established in the next week with formal notification via email together with a closing date for nominations to current members of the Joomla AU mailing list.
Any concerns?
A little unsure what comes first, the chicken or the egg. We want to have elections but can’t take paid memberships without access to the bank account so wondering what the process is for that.In reality I’m not expecting a flood of nominations and the subcommittee will likely be a combination of myself, Stuart Robertson, possibly Patrick Jackson and Terry Pollard, the current main organisers.I believe Stuart and I are still set up for bank account access and while we don’t have great plans to spend the surplus money from the last event, it may help with some setup costs.
How can LA assist?See above.Russell has said we can give the Joomla subcommittee access to strip and a bank account to allow collecting membership fees. Russel will deposit the Joomla surplus from last year into the bank account.Can’t give Joomla access to strip for the full year at the moment.
PyCon AU (Clinton and Peter)
Two PyCons 2024 and 2025
Benno reported on 2024 at the last meeting. The final financial result was a modest profit. PyconAU 2024 is now officially closed.
2025 – Early days, no approved budget yet.
Seeking quotes from venues, assembling a core team. Will send through a budget in the next couple of weeks.
Most like in September.
Russell: Why not the same venue? Answer: They’re expensive so looking for alternatives.
Neill to put Peter and Miles in touch with each other,
Flounder
LUV
WordPress
Everything Open 2025(Mike O’Connor)
Mike O’Connor – attended but we will catch up with him for a closing report later.
Everything Open 2026 (Miles Goodhew)
Early in the process
Carlos is assisting with the venue and gets the main venue for free
Three lecture theater style areas and three class rooms on the ground floor, plus 5 or so rooms on the 1st floor
Budgeting on 250 to 300 people.
14 people on the core team at varying levels of commitment
21st to 23rd January 2026 – last weekend of school holidays
A proposed schedule for organising the event has been sent to the council
Venue is free, but will need to cater for lunch and morning and afternoon tea. Lunch is necessary because of a lack of nearby venues. Have to use the UC caterer for everything.
7 quotes for penguin dinner options from $33k to $50. Will probably pick something in the middle.
One transport quote of $7000 for hotel transfers. Will seek some more.
Requests:
Template budget for Carlos and Arjen – Russell will look for one to send.
Neill will arrange to put Miles in touch with Peter, Jack and Nick
Admin Team
Nothing to report. Currently in a holding pattern
There was a change freeze for the election. There are other times (particularly when the larger conferences are active)
Some planned upgrades coming up – need to apply patches and updates to the website.
May have found a donor to provide brand new replacement HDD. Have been offered 12TB of storage.
No changes to the budget.
AUDA / Domain directors have charged us for the opensource.au holding registration.
No progress on actually getting the opensource.au domain. The expectation is that we will need to maintain the defensice registration for the foreseeable future. The cost for that is around $20/year
Planning to go ahead with a face to face meeting in Brisbane in late April or May.
Julian (who is looking to rejoin the admin team), Steve, Joel and along with a potential new member will meet to discuss future plans.
Russell: We are paying fastmail over $1,000/year which was not the arrangement we signed up for.
Steve: Sae Ra is chasing up why this happened. Not resolved yet. Steve will also chase this up.
4. Items for noting
Fastmail – if we can’t resolve the cost then we may have to find an alternative provider.
Approving subcommittee budgets is a matter of comparing the budgets supplied with last year’s results.
5. Other business
DrupalCon Japan 2025Budget:
[NC]: I have some concerns about the DrupalCon license fee – 30% of profit? What exactly is the Drupal Association providing in return? Is it just the use of trademarks? They seem to be taking a large chunk of money for little work or risk.
DrupalCon Singapore
KiwiPyConBudget:
[NC] Found the conservative case a bit confusing, but I gather it’s taking the highest expenses and lowest attendees?
WordCamp BrisbaneBudget: wcbne25-proposedbudget
[NC]: Some concerns about Automattic – we at least need to resolve the MoU
6. In camera
One item was discussed in camera
7. Action items
Neill: Put Miles and Peter in touch with each other.
7.1 Completed Items
Jonathan to respond to the Health Hack Committee
Neill to confirm email invitations to subcommittees for the next meeting.
Neill to draft a template for subcommittee responses – done by Joel
Neill to respond to Katie’s question about conference P&Ls
Neill to follow up with Russell re the $14K of office expenses at KiwiPyCon
7.2 Carried Forward
All council members to review the DrupalCon Singapore/Japan, KiwiPyCon and WordCamp Brisbane proposals.
Meeting closed at 22:11 AEDT
Next meeting is scheduled for 2025-03-12 at 20:00 UT+1100 (AEDT)
Meeting opened at 20:08 AEDT by Joel and quorum was achieved.
Minutes taken by Neill
2. Log of correspondence
2025-01-08 Letter to Linux Australia Inc. 11.12.24 – Russell has responded to Clayton Utz pointing out that the image on the LCA site is copyright by the European Space Agency, not Reuters
2025-01-09 [Linux-aus] EO2024 videos – questions about EO2024 videos – Joel has responded
2025-01-13 Enquiry from DAVID PASCOE via the Linux Australia Website Contact Form – fairly vague request for help. Jonathan has responded
2025-01-13 Notice of Linux Australia 2025 Council Elections and AGM – query from Kathy Reid re AGM Agenda. Neill has (belatedly responded)
2025-01-15 2024-2025 Annual report and Draft AGM Agenda- quite a lot of discussion, mostly centered around whether EO/LCA would run again. Some questions from Katie McLaughlin which Neill has answered, except for the one below
2025-01-15 Nice job on the Annual Report! Should it be posted to socials? – Kathy Reid asking if the Annual Report should be posted to our social media accounts – Sae Ra responded.
IRD loan – Kiwi PyCon/LA is getting money back – we will be receiving a refund from payments made to the IRD loan. Russell has responded
Job ads for linux tech – request to post a job ad. Neill has responded
It’s 2025, we’re ready for more Open Source! – newsletter from OSI
2025-01-16 Lodge Linux Australia Activity Statement October..December 2024
2025-01-21 DrupalCon Singapore – Report for Michael Richardson
2025-01-22 Adelaide Convention Centre – PYCON
2025-01-29 Everything Open 2026 bid for Canberra – From Miles Goodhew
2025-01-30 Possible malicious subscribers on LA list – Arjen Lentz. Request to remove Rory Croker
2025-01-31 Re: [LACTTE] Is it time to shut down the HH LA Subcommittee?
2025-02-01 Re: [Linux-aus] FOSS social media (inappropriate response from Rory Croker)
2025-02-02 Clarification on PyCon AU 2024’s LA subcommittee type? – Russell and Joel have responded
2025-02-05 [LACTTE] DrupalCon Japan – Proposed Budget
2025-02-07 Application to form a Kiwi PyCon 2025 subcommittee – Joel has responded
2025-02-10 WordCamp Brisbane 2025 subcommittee – Joel has responded
2025-02-10 Call for OSI board nomination
2025-02-10 Fwd: Re: DEFAMATION CONCERN NOTICE – Re: [Announce] LA needs a new constitution – several emails on this topic. Council has dealt with this [FIXME]
Many, many other emails, but these are the most important ones
3. Items for discussion
Question from Katie McLaughlin: “ There appear to be other inconsistencies with the P&L of conferences reported. Is this just an effect of bundling some costs differently to other events? (e.g. EO2024 reports a profit, but reports no event management, food and drink costs, whereas the PyNZ24 reports triple the venue hire of EO2024, zero food and drink or event management, but 14k in “office expenses”.”
Comes down to the areas that the conferences use, sometimes the venue reports catering and venue costs in the one line item.
We will look into the 14k office expenses for Kiwi PyCon
DrupalCon Singapore 2024 and proposed Japan 2025
We have not yet had time to go through this report in detail.
It looks like they have managed to make an $18k profit, which is an impressive turnaround.
They are looking at putting in a bid to run another conference in Japan, but we need to have a clear understanding of what it would mean for LA, especially in terms of tax implications.
[RS]: If we do not exceed AUD$100,000 (approximately, converted from JPY) ticket sales to Japanese residents we will not have any tax obligations in Japan.
[JW] Question about liability for losses – normally these run through a professional events company – what would our liability for losses be?
[RS] The Drupal Association asks for a percentage of revenue which is not acceptable.
[JA] The DA is keen to move to a percentage of revenue. We need a new agreement to run the next conference anyway. Not keen to commit to a percentage of revenue as that exposes LA to more risks. Apart from tax, the other item to be sorted out is insurance.
[JC] What is the DA giving to the conference?
[JA] They dedicate some resources for marketing and possibly send some people to the conference. Need to dig into the details more.
[RS] We should be able to ask our accountant about the tax implications.
We may need a separate meeting to discuss this with the organising team.
Everything Open 2026 bid for Canberra
Miles has started the process of building a team to bid to run EO in Canberra in 2026.
Carlos from OpenSI is also keen to host the event in Canberra. Carlos has concerns about the effort involved, but is keen to run the conference. It would be good if Carlos spoke to Miles.
OpenSI (and Carlos) have sponsored the last two Everything Opens.
Rory Croker
Has been removed from the mailing list after sending a number of strange emails to the list and then contacting people on the list directly in inappropriate ways.
He was warned that if he didn’t stop he would be unsubscribed. He did not stop and has now been unsubscribed.
Health Hack LA Subcommittee
Have told us they are at least pausing things, until such time as they find new people to run events.
They have asked for $1,000 for “contingencies” which is difficult. They should submit expense claims instead.
We should also offer to provide hosting for them in order to reduce their expenses.
Defamation Concern Notice
Council has received a defamation concern notice. This has been discussed at a separate meeting. We are waiting for a response.
Kiwi PyCon
We received a budget and starting team. Council has not yet had time to go through the proposal in detail. Council members will individually review the proposal over the next few days and discuss any issues as a group.
WordCamp Brisbane
Again. Council has not yet had time to go through the proposal in detail. Council members will individually review the proposal over the next few days and discuss any issues as a group.
We have particular concerns around the WordPress/WordCamp central entities and their recent actions.
4. Items for noting
Jonathan has had several people suggest that we edit the old LCA website to point visitors to the new Everything Open website.
The constitution may be in its final form. No new changes have been received lately. We will need to make some changes to how we deal with membership applications.
Joel will reach out to Lyndsey Jackson who has a contact that has helped other organisations make constitution changes.
5. Other business
None
6. In camera
None
7. Action items
Jonathan to respond to the Health Hack Committee
All council members to review the Drupal Con Singapore/Japan, KiwiPyCon and WordCamp Brisbane proposals.
Neill to confirm email invitations to subcommittees for the next meeting.
Neill to draft a template for subcommittee responses.
Neill to respond to Katie’s question about conference P&Ls
Neill to follow up with Russell re the $14K of office expenses at KiwiPyCon
7.1 Completed Items
7.2 Carried Forward
Meeting closed at 21:32
Next meeting is scheduled for 2025-02-26 at 20:00 UT+1100 (AEDT) which will be a subcommittee meeting.
Meeting opened at 19:35 AEDT by Joel. Quorum was achieved.
Minutes taken by Neill and Jonathan..
2. Log of correspondence
This is correspondence which was sent to Council. Any communication sent directly to the secretary or other executive addresses is not included.
Today’s Meeting [Drupal Con Japan] – Russell has responded
PyCon AU 2025 Proposal – Russell has informed PyCon Au that they have been approved as a subcommittee
Congratulations [from Sae Ra re new constitution] – Joel has responded
Adoption of new Constitution by Linux Australia Y2998126 [Russell notifying NSW Fair Trading of adoption of the new constitution
ANZ Direct Online Enquiry – Linux Australia – ATTN Diesel – Russell has responded
Kiwi PyCon 2025 subcommittee financial access – Russell has responded
pycon steering committee updates – Joel has responded
Grant Application – Makerspace Adelaide have withdrawn their application. Jonathan to acknowledge receipt and thank them for the information..
Re: Notice of Special General Meeting for Linux Australia – proxy registration for the SGM from Karl Goetz – Neill has responded
[LACTTE] BAS Time – discussion about Xero access for WC Brisbane – Joel and Russell have responded
[LACTTE] DrupalCon Nara 2025 – Drupal Association Agreement – On list motion – discussion of Drupal Association agreement
Everything Open 2025 Wrap up post – for approval before going live – discussion of EO2026 Wrap up post which has now been published
Fwd: LINUX AUSTRALIA INCORPORATED – Y2998126 – A6 Conf – JL – NSW Fair Trading have accepted the new constitution
Lodge Linux Australia Activity Statement January..March 2025 – Russell has asked the accountant to lodge our BAS
Sharing our standard sponsor agreement for PyCon AU 2025 – Discussion about standard sponsorship agreements – Joel has responded
Remittance Advice – from RedBubble
You’re missing out on personalized insights & tips – Google Analytics [[do we care?]]
auDA strategy 2026-2030 consultation paper is out – Kathy Reid notifying council. Joel to respond: time constraints prevent council responding.
Inquiry: Running Purplecon again in 2025 – Russell has responded. Some analysis work done by Elena. More work is needed on the budget. Aim to do this over the next two weeks and send questions to the organisers as they come up.
Maintainer Month in May – from OSI
Question with notice: Is the LA tax still 6%, or should it increase? – Question from Miles Goodhew – Joel has responded
3. Items for discussion
Subcommittee: Kiwi Pycon 2025
Venue is booked, first payment due
Treasurer is not yet authorised with ANZ.
Some sponsors have signed – one bronze and in kind
No high level sponsors yet
Still a month of early bird sales to go
Discussing trans-tasman sponsorship with Jack Skinner
Want to get sponsorship to a good level – there is an early bird discount for sponsors up until 6 months before the conference
Q: Should Kiwi PyCon look for a sponsorship sales person who would work on a 20% commission? Commission paid for one year only for new sponsors. This would only start after the early bird expires.
A: Council needs to think about this before giving an answer.
Russell: PyCon NZ will need a second person to authorise payments. At the moment Chelsea is yet to be added which means that only two authorised people are on the list. Would be better to have some redundancy.
Seed money has been placed in the ANZ account.
Subcommittee: Admin team
Not a lot to report in the last month
Fastmail are pinging back and forth on support tickets re pricing.
Steve Will be catching up with Mike Beattie in about two weeks.
Things are getting busy for people, which may push the face to face out to August and perhaps be only one meeting.
Debian project sysadmins have reported an issue with some hosts (three) on the ANU are failing with connection resets. Steve is chasing this with ANU. May be related to dual addresses. These are the Debian security archive hosts. Elena has physical access if needed.
Subcommittee: Drupal South Melbourne 2025 Russell will arrange for Drupal South to keep the same bank account year to year.If Drupal South wants to run a merch store we will need to discuss how LA can manage the strip account.Invoices can be paid into the old account and LA can then transfer the funds internally. Unfortunately that perhaps does not help at this point.The LA council will look for solution to the problems of multiple back accounts
Subcommittee: PyCon AU 2025
Amended venue contract has been received. Pete expects to review and sign tomorrow.
Have signed the first sponsor – Google Australia
Steering Co question on notice: Has LA got all the process documents required?
A: We think we have everything, but LA council will check.
Treasurer Update: Ariba invoice has been rejected once due to address problems. It has been re-submitted.
DrupalCon Japan
Conference has been announced at DrupalCon Atlanta – much excitement at the announcement
Mike has visited Nara done a hotel inspection which went well.
Had a meeting with the Mayor
The city is interested in sponsoring and wants to send some students.
Mike spoke at the local Drupal meetup.
Call for volunteers went out today.
Need the signed contract for the Drupal Association
Subcommittee: Wordcamp Brisbane 2025
Tickets on sale (25 sold)
Sponsorships (12) under review of WordCamp Central
Sponsorship agreements are ready to be sent out
Speakers submitting presentations (23 presentations) closing date 24/4/2025 with possibility to extend
Another venue walk through on 29/04
Presentation to students
The ticketing system (Humanitix) may not be an approved system. Some discussion with WordCamp Central about whether the ticketing system needs to be changed
Subcommittee: Joomla
No current events planned
Need to sort out a bank account and Stripe access for Joomla.
Subcommittee: Flounder
Last meeting was on on 19 April and about LLM models
Have a new server
Has been difficult to recruit new members
Subcommittee: EO2026
Had a meeting last night to discuss budget
In the spreadsheet the projections are based on Forecast as the pessimistic option
Expected – optimal based on last years conference
Sponsorship assumptions for the pessimistic option are very pessimistic.
Because of SI sponsorship the Venue is free but must use the venue’s catering
Catering assumptions for the pessimistic option is just morning and afternoon tea, but the expected option is that lunch will need to be provided because of the lack of nearby food options.
Transport for attendees from hotels is being budgeted for.
Miscellaneous costs are difficult to quantify at the moment, in particular need some guidance about AV costs. Childcare is included in the optimistic version but is unlikely to be provided. Joel will arrange a meeting to discuss the budget with Miles.
Good to see progress, the council is keen to see a launch soon.
Carlos: Do we have a timeframe?
Answer: As soon as we can finish reviewing the budget then we can sign off, hopefully before the end of the month.
SGM
Constitution passed, submitted to NSW Fair Trading. Accepted by NSW Fair Trading. Now in effect. Is now on the website.
Bank accounts
The increased number of active subcommittees and events of late has resulted in a need for additional bank accounts and Stripe accounts to service them. Some subcommittees (Joomla, Drupal) are also commencing activities which require permanent accounts.
Russell will follow up with the bank to create new accounts.
Russell will follow up with Stripe for new accounts (one for Joomla, one for Drupal).
There is a Stripe account fee discount applicable for non-profit entities. In practice this means being a registered charity. Russell will follow up with the Australian Charities and Not-for-profit Commission (ACNC) to determine what needs to happen to get LA registered as a charity. This will make it much easier to get the discount for the new Stripe accounts.
Bank accounts and sponsorship payments
Suggest that LA establish a dedicated bank account to receive sponsorship for all events. LA then assigns the incoming payments to the Xero areas of the respective events.
4. Items for noting
None.
5. Other business
None.
6. In camera
None
7. Action items:
Bank accounts for Drupal South
Drupal meeting
Bank Account for Joomla
Access to Stripe for Joomla
Meet with Miles to discuss EO2026 budget
Meeting closed at 21:07 AEST (UT+1000).
Next meeting is scheduled for 2025-05-07 19:30 AEST (UT+1000)
Meeting opened at 19:32 AEST by Joel and quorum was achieved.
Minutes taken by Neill
2. Log of correspondence
[LACTTE] BAS Time
Grant Application – Makerspace Adelaide
Big News for Open Source—From the UN to the OSI new directors
Amazon Web Services Billing Statement Available [Account: 103334912252]
Kiwi PyCon 2025 subcommittee financial access
Word Camp Brisbane Conference 2025 has been accepted
Payment Processed for 411597 – Payment of Zoom account
Re: Linux Australia Induction – Linux Victoria New Treasurer
ANZ Direct Online Enquiry – Linux Australia – ATTN Diesel – Russell has responded
pycon steering committee updates – Joel has responded
Re: Notice of Special General Meeting for Linux Australia – Proxy registration for Karl Goetz
SGM vote 9th April – apology and nomination of proxy in favour of the motion to adopt the new constitution – Proxy registration for Kathy Reid
Apology for SGM – Proxy registration for Cameron Tudball
Confirmation of Proxy – Proxy registration for Donna Benjamin
Linux Australia SGM – Proxy Vote – Proxy registration for David Ball
3. Items for discussion
PyCon AU 2025Motion: That an event subcommittee be established for PyCon AU 2025 based on the provided budget.
Moved by: Joel Addison
Seconded: Jennifer Cox
Passed with one abstention
4. Items for noting
DrupalCon JapanJoel has received the agreement which looks like it contains everything we want, but needs one item clarified.
Once Joel has received clarification we will move a vote on the final document via email.
DrupalCon Singapore How do we deal with the payment to the Drupal Association of the 30% of net profit.Russell will liaise with the DrupalCon Singapore treasurer to ask for an invoice from the Drupal Association once the amount is confirmed.
EO 2025 Wrap Up document Joel has spoken to Miles to check if anything else needs to be in the document. Miles is currently overseas.
Some tweaks still need to be made, particularly about the miniconfs and miniconf organisers participation in the session selection committee.Joel will revisit the document sometime after the SGM is finished.
5. Other business
6. In camera
No items were discussed in camera
7. Action items
7.1 Completed Items
7.2 Carried Forward
Meeting closed at 19:51 AEST
Next meeting is scheduled for 2025-04-23 and is a subcommittee meeting.
Meeting opened at 20:18 AEDT by Joel and quorum was achieved.
Minutes taken by Neill
2. Log of correspondence
Julie Elliott: Adelaide Convention Centre – SYDNEY potential coffee catch up / meeting
Kathy Reid: Logitech sponsoring unihack
Various Drupal South: Purchase Approval Request DrupalSouth
Russell Stuart: Comments on upcoming conference budgets
Michael Richardson: DrupalCon Japan – Proposed Budget
Russell Stuart: Example conference budget spreadsheet
Alex Leith: Sponsorship request from Global FOSS4G 2025 conference via Jonathan
Wil Brown: New Scanned Post – placed in Google Drive
OSI: Community contributions: Call to action
Australia Post: Payment for your PO Box is due soon (Updated Invoice)
OSI: Open Source Initiative Affiliate directors elections 2025
OSI: OSI Elections: unsolicited emails
Miles Goodhew: Fwd: EO2026CBR Schedule
3. Items for discussion
DrupalCon Japan
Have sent through their budget. They want an answer as soon as possible. Sponsorship seems too high. The Drupal South conference has a Titanium level sponsor as a result of DrupalCon Singapore. We do have some reservations, but Michael and the DrupalCon Singapore team did do a remarkable job last year. We will need to track things carefully this year. Need to make sure that we will not have tax complications in Japan. Ensure that if necessary some expenditure can be cut.Motion: That Linux Australia accepts DrupalCon Japan as a subcommittee and approves the budget for DrupalCon Japan subject to the condition that the DrupalCon Japan team and Linux Australia needs to negotiate with the Drupal Association on the profit return arrangement – this should be based on profit, not income, and that profit is *after* the LA overheads are deducted.
Moved by: Joel
Seconded: Neill
Outcome: Motion passed
Discussed scenario where Drupal Association don’t accede to this agreement. It would depend on how they respond, in the worst case scenario we will withdraw our support.
Kiwi PyConWe have received a budget with updated sponsorship and attendance assumptions. They are projecting a loss, even with fairly optimistic sponsorship estimates.We need to speak with them to see if there is any way to improve this budget. Projecting a loss at the very beginning leaves no room for possible contingencies.There would be a profit if not for the payment to LA to cover insurance and overheads.
Russell will discuss our concerns over the budget with KiwiPyCon.
Motion: That Linux Australia accepts Kiwi PyCon 2025 as an event subcommittee based on the provided budget.
Moved by: Joel
Seconded: Elena
Outcome: Motion passed
WordCamp Brisbane Again there are some concerns about this budget. We will ask them to provide a budget based on our standard template.Russell will organise a meeting with the WordCamp subcommittee.
Insurance RenewalWe need to go through the process of renewing our insurance in about a month’s time. Joel has the forms and will need some information from Russell to complete them.We also need to list out all of the upcoming events for the next year. Joel will contact the subcommittees to confirm that list.
Constitution Update No new comments on the pull request, so now looks like a good time to start preparing to call the special general meeting and put the changes to a vote. We need to prepare communications to start this process.We will aim to hold the special general meeting on 9/Apr/2025 at 20:00 AEST.
FOSS4G 2025 Sponsorship
Jonathan will respond (decline: LA has no sponsorship budget in 2025)
PyConAU datesWe need to get the PyConAU dates and budget confirmed soon – the PyConAU organising committee is very close to finalising these. The delay has been to do with confirming details with possible venues
4. Items for noting
5. Other business
6. In camera
Two items were discussed in camera
7. Action items
7.1 Completed Items
7.2 Carried Forward
Meeting closed at 21:46
Next meeting is scheduled for 2025-03-26 and is a subcommittee meeting.
Neill Cox (Secretary) (approx 20:30 to 21:00 AEDT)
Elena Williams (Council)
Jonathan Woithe (Council)
Apologies
Jennifer Cox (Vice-President)
Neill Cox (Secretary)
Lilly Ho (Council)
Meeting opened at 20:30 AEDT by Russell. Quorum was achieved.
Minutes taken by Jonathan.
2. Log of correspondence
This is correspondence which was sent to Council. Any communication sent directly to the secretary or other executive addresses is not included.
Vladimir Roudakov: Follow ups to Wordcamp Brisbane meeting with Joel and Russell.
Clinton Roy: Updates about PyCon AU steering committee.
Michael Richardson: Notification of DrupalCon Nara announcement. Apology for being unable to attend this subcommittee meeting.
Peter Hall: PyCon AU 2025 proposal.
Kathy Reid: Follow up about the Everything Open 2025 wrap-up document.
Kathy Reid: Notification that that SGM notice has been published on LA socials.
Redbubble: Sale and manufacturing notifications.
Michael Richardson: Progress update on DrupalCon Nara.
Kathy Reid: The Everything Open Bluesky handle had an issue due to an expired everythingopen.au SSL certificate.
Sae Ra Germaine: Everything Open 2025 wrap-up document draft for review and approval
3. Items for discussion
Subcommittee: Kiwi Pycon 2025
A budget has been approved. Financial induction done. The budget spreadsheet has been reworked according to feedback received.
Conference expenses will be optimised.
Russell is very pleased with the improvements to the budget documentation..
Venue is confirmed. Chelsea will sign the contract soon.
Date and location is published on the website. An official announcement will follow.
Sponsorship campaign has started. Prospectus has been sent to approximately 120 contacts.
Co-chairs for the paper selection group have been put in place.
Subcommittee: Admin team
Business as usual.
Steve had a discussion with Bron from Fastmail at IETF to discuss formalising the sponsorship arrangement. A follow up discussion will be held next week.
Face-to-face is still being planned. It will be held in Brisbane. There will be 6 attendees: Steve, Mike, Julian, a possible new member, Joel, and possibly one other person. Only Steve and Mike will need to travel: everyone else is in Brisbane.
Subcommittee: Drupal South Melbourne 2025
A budget with a notional profit of $19k was presented (after deducting LA overheads).
Good feedback was received about the event.
Drupal South would like to discuss a number of things which have arisen during the conference and other discussions:
How much of the profits can Drupal South use? Are there limits on what kinds of things the profits can be used for.
The subcommittee want to run workshops or webinars for vendors to help drive adoption.
Establishment of a merchandise shop
Having a different bank account each year is awkward, especially for many of the sponsors in the government space. They would like a fixed bank account. They are also thinking of linking the shop to the bank account. From Russell: this would also require a dedicated Stripe account.
Joel and/or Neill will work with Julia to arrange a suitable time.
Council found the event summary to be clear and concise.
Subcommittee: PyCon AU steering committee
Jack has joined the steering committee to help resolve capacity constraints. His particular focus is on sponsorship and multimedia.
Jack is in the early stages of costing a PyCon AU 2026. The motivation is to provide organising teams with longer lead times.
Peter would like approval as soon as possible, but within two weeks would be good. There is pressure to commit to a venue to guarantee availability.
PyCon AU would like to push PyCon AU as a formal professional development opportunity. This would encourage employers to send staff and sponsor the event. Having a program published by June is desired to facilitate this. This is another reason for wanting a rapid turnaround with the budget approval process.
There is a deliberate decision to re-introduce an online component.
The attendance figures in the budget: “Bare Bones” is 2024 attendance minus 5%, “Expected” is 2024 attendance plus 5%, “Best” is 2024 attendance plus 10%.
The bare bones case currently shows a significant loss.
Some python-related events are now showing a return to 2019 attendance levels.
Council aims to address the budget approval by the end of the coming weekend. Russell will go through the documents provided and send feedback to Council.
There is one sponsor for 2025 already committed.
Russell noted that the budget has been well prepared.
Subcommittee: EO2026.
Final quote received from UC Events for the venue. This came in line with expectations.
Treasurer is sorted (Arjen). A budget is being prepared. It is hoped to have a draft ready in about two weeks. Having it finalised by the end of April may be possible.
Content discussions have kicked off. The plan is to keep the event similar to 2025.
Joel and Miles will catch up during next week to go through some of the finer planning points.
The aim is to try to run to an earlier time frame than for 2025’s conference.
A wiki is planned for crowd-sourced organisation.
Subcommittee: Wordcamp Brisbane 2025
Joel and Russell met earlier this fortnight to discuss budget details. For 2026 the aim is to use the LA budget template.
Wordcamp Central has given approval and global sponsorship.
The goal is to ensure a break even financial position or better.
Venue and AV sponsors have been identified.
Wordcamp Central now require that all sponsors be vetted by them.
The website is ready. Call for sponsors is ready. Call for papers is one day away.
SGM
There have been some questions about proxy votes. The current constitution allows them. They are being referred to Neill.
Wordcamp Brisbane approval
The budget concerns identified by Joel and Russell were resolved at the earlier email.
Motion by Joel: that Linux Australia accepts Wordcamp Brisbane 2025 as an event subcommittee.
Seconded: Jonathan
Motion was passed.
Russell will communicate the result to the subcommittee.
DrupalCon Nara
Joel has received the licence agreement from Drupal Association.
This will be signed so long as the Drupal Association takes a profit share, not a revenue share.
Joel will follow up.
Next council meeting
The SGM is at 20:00 UT+1000 (Melbourne time, no daylight saving)
Council will meet at 19:30 UT+1000 on Jitsi.
4. Items for noting
We need to consider seeking bids for Everything Open 2027 soon.
5. Other business
None.
6. In camera
None
Meeting closed at 21:32.
Next meeting is scheduled for 2025-04-09:
Council at 19:30 UT+1000 (Tas, VIc, NSW, Qld), 19:00 UT+0930 (SA, NT)
I run my own mail server. I have run it since about 1995, initially on a 28k8 modem connection but the connection improved as technology became cheaper and now I’m running it on a VM on a Hetzner server which is also running domains for some small businesses. I make a small amount of money running mail services for those companies but generally not enough to make it profitable. From a strictly financial basis I might be better off just using a big service, but I like having control over my own email. If email doesn’t arrive I can read the logs to find out why.
I repeatedly have issues of big services not accepting mail. The most recent is the MS services claiming that my IP has a bad ratio of good mail to spam and blocked me so I had to tunnel that through a different IP address. It seems that the way things are going is that if you run a small server companies like MS can block you even though your amount of spam is low but if you run a large scale service that is horrible for sending spam then you don’t get blocked.
For most users they just use one of the major email services (Gmail or Microsoft) and find that no-one blocks them because those providers are too big to block and things mostly work. Until of course the company decides to cancel their account.
What we need is for each independent jurisdiction to have it’s own email infrastructure, that means controlling DNS servers for their domains, commercial and government mail services on those domains, running the servers for those services on hardware located in the jurisdiction and run by people based in that jurisdiction and citizens of it. I say independent jurisdiction because there are groups like the EU which have sufficient harmony of laws to not require different services. With the current EU arrangements I don’t think it’s possible for the German government to block French people from accessing email or vice versa.
While Australia and New Zealand have a long history of cooperation there’s still the possibility of a lying asshole like Scott Morrison trying something on so New Zealanders shouldn’t feel safe using services run in Australia. Note that Scott Morrison misled his own parliamentary colleagues about what he was doing and got himself assigned as a secret minister [2] demonstrating that even conservatives can’t trust someone like him. With the ongoing human rights abuses by the Morrison government it’s easy to imagine New Zealand based organisations that protect human rights being treated by the Australian government in the way that the ICC was treated by the US government.
The Problem with Partial Solutions
Now it would be very easy for the ICC to host their own mail servers and they probably will do just that in the near future. I’m sure that there are many companies offering to set them up accounts in a hurry to deal with this (probably including some of the Dutch companies I’ve worked for). Let’s imagine for the sake of discussion that the ICC has their own private server, the US government could compel Google and MS to block the IP addresses of that server and then at least 1/3 of the EU population won’t get mail from them. If the ICC used email addresses hosted on someone else’s server then Google and MS could be compelled to block the addresses in question for the same result. The ICC could have changing email addresses to get around block lists and there could be a game of cat and mouse between the ICC and the US government but that would just be annoying for everyone.
The EU needs to have services hosted and run in their jurisdiction that are used by the vast majority of the people in the country. The more people who are using services outside the control of hostile governments the lesser the impact of bad IT policies by those hostile governments.
One possible model to consider is the Postbank model. Postbank is a bank run in the Netherlands from post offices which provides services to people deemed unprofitable for the big banks. If the post offices were associated with a mail service you could have it government subsidised providing free service for citizens and using government ID if the user forgets their password. You could also have it provide a cheap service for non-citizen residents.
Other Problems
What will the US government do next? Will they demand that Apple and Google do a remote-wipe on all phones run by ICC employees? Are they currently tracking all ICC employees by Android and iPhone services?
Huawei’s decision to develop their own phone OS was a reasonable one but there’s no need to go that far. Other governments could setup their own equivalent to Google Play services for Android and have their own localised Android build. Even a small country like Australia could get this going for the services of calendaring etc. But the app store needs a bigger market. There’s no reason why Android has to tie the app store to the services for calendaring etc. So you could have a per country system for calendaring and a per region system for selling apps.
The invasion of Amazon services such as Alexa is also a major problem for digital sovereignty. We need government controls about this sort of thing, maybe have high tariffs on the import of all hardware that can only work with a single cloud service. Have 100+% tariffs on every phone, home automation system, or networked device that is either tied to a single cloud service or which can’t work in a usable manner on other cloud services.
I’ve been looking at computer hardware on AliExpress a lot recently and I saw an advert for a motherboard which can take 256G DDR4 RDIMMs (presumably LRDIMMs). Most web pages about DDR4 state that 128G is the largest possible. The Wikipedia page for DDR4 doesn’t state that 128G is the maximum but does have 128G as the largest size mentioned on the page.
Recently I’ve been buying 32G DDR4 RDIMMs for between $25 and $30 each. A friend can get me 64G modules for about $70 at the lowest price. If I hadn’t already bought a heap of 32G modules I’d buy some 64G modules right now at that price as it’s worth paying 40% extra to allow better options for future expansion.
Apparently the going rate for 128G modules is $300 each which is within the range for a hobbyist who has a real need for RAM. 256G modules are around $1200 each which is starting to get a big expensive. But at that price I could buy 2TB of RAM for $9600 and the computer containing it still wouldn’t be the most expensive computer I’ve bought – the laptop that cost $5800 in 1998 takes that honour when inflation is taken into account.
DDR5 RDIMMs are currently around $10/GB compared to DDR4 for $1/GB for 32G modules and DDR3 for $0.50/GB. DDR6 is supposed to be released late this year or early next year so hopefully enterprise grade systems with DDR5 RAM and DDR5 RDIMMs will be getting cheaper on ebay by the end of next year.
Related posts:
HP z840 Many PCs with DDR4 RAM have started going cheap on...
The following is an illustration of how to use xargs to conduct parallel operations on single-threaded applications, specifically wget.
GNU wget is a great tool for downloading content from websites. The wget command is a non-interactive network downloader; by "non-interactive" what is meant is that it can be run in the background. Some very hand options include -c (continue, for partially downloaded files), -m (mirror, for an entire website), -r --no-parent (recursive, no parent, to download part of a website and its subdirectories). The cURL application has a wider range of protocols and includes upload options, but is non-recursive.
Recently, I had the need to download a small number of PDF files. The wildcard-based approach would be:
$ wget -r -nd --no-parent -A 'rpgreview_*.pdf' http://rpgreview.net/files/
The -r and --no-parent options have already been explained. The -nd option allows one to save all files to the current directory, without hierarchy of directories. The -A option ('accept', or -R 'reject) allows one to specify comma-separated lists of file name suffixes or patterns to accept or reject. Note that if any of the wildcard characters, *, ?, or ranges [] to be in an acclist or rejlist.
Running the above has the following time:
real 2m19.353s
user 0m0.836s
sys 0m2.998s
An alternatiive, looping through each file one at a time, would have been something like:
for issue in {1..53}
do
wget "https://rpgreview.net/files/rpgreview_$issue.pdf"
done
(Just for the record, wget can get a bit gnarly when dealing with http requests because for some webservers there is no requirement for path delimiters to match directory delimiters. For the purposes of this discussion it is assumed that we're dealing with a rational being where the two are equivalent.)
Using a combination of the printf command and the xargs command a list of the URLs can be constructed which is then passed to xargs which can split the list to run in parallel.
By itself, xargs simply reads items from standard input, delimited by blanks or newlines, and executes commands from that list of items as arguments. This is somewhat different to the pipe command which, by itself, sends the output of one command as the input stream to another. In contrast, xargs takes data from standard input and executes a command which, by default, the data is appended to the end of the command as an argument. However, the data can be inserted anywhere however, using a placeholder for the input; the typical placeholder is {}.
The value -P 8 is entirely arbitrary here and should be modified according to available resources. Adding -nc prevents xargs attempting to download the same file more than once (wget will not overwrite an existing file, but rather append a new file with .1, etc. The -n option ensures that only one argument is run per process.
A final option, most common in high-performance computing systems with job schedulers, is to make use of a job array. This is effective assuming resource availability. This is a very effective option if each task in the array takes more than a couple of minutes each (given that there is an overhead involved in constructing the job, submitting it to the queue, etc). In Slurm, a script the directives and code would look like the following:
Then, I rebooted it, and discovered I needed /etc/fstab, so I did some manual stuff to boot it into single user mode and get it working.
Anyway, that was a fun trip down 2007 era hardware lane, and I found some bugs in ethernet drivers that use miibus (see kern/286530 - https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=286530 - for more info.)
This book is a history of the Bell Labs run by AT&T for much of the 20th century. These are the labs which produced many of the things I use day to day — Unix and the C programming language for example, although this book focuses on other people present at the lab, and a bit earlier than the Unix people. Unix, a history and a memoir for example is set in the same location but later in time.
One interesting point the book makes early is that the America of the early 20th century wasn’t super into scientists, it was much more about engineers. So for example Edison was an engineer whose super power was systematically grinding through a problem space looking for solutions to a problem, but not necessarily actually understanding the mechanism that caused the solution to work. A really good example, although not one of Edison’s, is adding lead to fuel to stop engine knocking and wear — they literally walked the periodic table until they found an element that worked. I am left wondering how much of this failure to understand the underlying mechanism was a contributor to the longer term environmental and health implications of these innovations — would a competent scientist have produced the same product given a knowledge of the likely outcomes? This is worry in the context of modern America becoming increasingly anti-science. Will there be a reverse to the former brute force approach and ignoring longer term consequences?
The book discusses the invention and manufacture of the vacuum tube, an invention necessary to create the transcontinental phone system that AT&T Long Lines so desired. This story is told in the context of the careers of early labs hires, who were all Members of Technical Staff (MTSes), a job title still used by several FAANG companies to this day.
There’s then the story of early work towards what we’d now call a transistor to replace the energy intense and fragile vacuum tubes. This effort was however derailed by being pulled into America’s WW2 efforts. Along the way they might of invented nuclear reactors just a little (but probably after others). An interesting aspect to this story that I hadn’t heard before is the controversy around William Shockley — a highly competitive man who committed the cardinal sin (in AT&T culture at least) of competing with his own direct reports. Later in the book we also learn that Shockley was a racist eugenicist, so that’s nice.
Next up is a brief introduction to Claude Shannon’s work on what we now call Information Theory — the idea of how to quantify the maximum amount of information you can reliably transmit on a given channel. This was by far my favourite subject at university while studying computer engineering, so I particularly enjoyed this section. I’ve had a book about Shannon on my reading to-do list for a long time, I really should get around to reading it soon. Ironically I read the description of Shannon as effectively someone with very high functioning ADHD and possibly autism. He was just lucky enough to find an environment that valued brilliance over conformity.
We then pivot back to the development of silicon transistors (as opposed to the previous germanium ones) and ultimately the first practical solar cell. Sadly that solar cell from the early 1950s was too expensive to make to be economically viable, but it was certainly a glimpse of the future. Bell Labs would return to those solar cells later in the book to solve another interesting problem.
It must have been difficult to write a book like this — there are simply so many inventions which changed our world to cover. In the context of the development of both satellite communications (both first with passive Mylar balloons and then active satellites) and cellular telephony, it is likely fair that the development of Unix and C only receive a few paragraphs. However, it certainly doesn’t map to my own personal biases well given the later two are the underpinnings for basically all modern internet scale technologies.
Bell Labs ultimately didn’t survive the break up of AT&T. Something with its name did, but it simply wasn’t the innovative place it once was. The book uses it’s closing chapter to ask an interesting question I think could use more examination than the book gives it — is the America of today trading on the innovations of 50 years ago made by places like Bell Labs? Or is there true “great leap forward” innovation still occurring in America. I think it’s worryingly possible the former is true. The book also argues that government research funding to a large extent replaced the torrent of cash that the early telephony monopoly gave Bell Labs. With global cuts in research funding that might not be true for long.
One minor disappointment with this book is that it is mostly descriptive — the who, the what, and the when. I see a missed opportunity here to try and explain why Bell Labs was as successful as it was. For over 60 years they were the leading industrial research lab in the world, which is a pretty impressive feat. The book does spend a few pages at the very end sort of playing with ideas around this, but overall it feels like an after though. Perhaps that question isn’t answerable, but I would have liked to have seen Gertner at least try a bit harder.
The Idea Factory
Jon Gertner
Business & Economics
Penguin
March 15, 2012
434
The definitive history of America’s greatest incubator of innovation and the birthplace of some of the 20th century’s most influential technologies “Filled with colorful characters and inspiring lessons . . . The Idea Factory explores one of the most critical issues of our time: What causes innovation?” —Walter Isaacson, The New York Times Book Review “Compelling . . . Gertner's book offers fascinating evidence for those seeking to understand how a society should best invest its research resources.” —The Wall Street Journal From its beginnings in the 1920s until its demise in the 1980s, Bell Labs-officially, the research and development wing of AT&T-was the biggest, and arguably the best, laboratory for new ideas in the world. From the transistor to the laser, from digital communications to cellular telephony, it's hard to find an aspect of modern life that hasn't been touched by Bell Labs. In The Idea Factory, Jon Gertner traces the origins of some of the twentieth century's most important inventions and delivers a riveting and heretofore untold chapter of American history. At its heart this is a story about the life and work of a small group of brilliant and eccentric men-Mervin Kelly, Bill Shockley, Claude Shannon, John Pierce, and Bill Baker-who spent their careers at Bell Labs. Today, when the drive to invent has become a mantra, Bell Labs offers us a way to enrich our understanding of the challenges and solutions to technological innovation. Here, after all, was where the foundational ideas on the management of innovation were born.
Since I posted by idea for two Auckland light Metro lines I’ve had some feedback and made some updates. This is the new version of the article. At the bottom of this article I’m written about the changes and reasoning behind them. You can also read my article on Light Metro Technology to get more information about the technology I am proposing be used.
Below is the new network I am planning as a basis for Auckland. It consists of
The existing Heavy Rail network (Dark blue).
A street running light Rail along Queen Street and Domain Rd (Red)
A North/South from the North Shore to the CBD and then the Airport (Green)
A Western line from the CBD to Westgate ( yellow )
In this post I’ll cover the North/South line. Not that all pictures/maps in the article can be opened to see the larger version
Light Metro Technology
As outlined in a previous article Light Metro is Automated (driverless), Grade Separated with Short Trains and High Frequencies. It is well suited to Auckland where requirements exceed Light Rail but a full metro would be overkill.
The key advantages of Light Metro over street running light rail is it’s high capacity, frequency and higher speed. Attempting to push Light Rail beyond it’s natural sweet-spot result in a grade-separated system that costs as much as Light Metro but is worse and often costs more to run.
The below table shows the capacity of a Light Metro line (in each direction). For Auckland the stations outside the CBD could be serviced by buses to further increase coverage area. Trains could start at short length and frequency increased as high as possible before longer trains should be used.
Headway / Trains per Hour
2 Cars
3 Cars
4 Cars
6 Cars
5 min / 12 tph
2,400
3,600
4,800
7,200
3 min / 20 tph
4,000
6,000
8,000
12,000
2 min / 30 tph
6,000
9,000
12,000
18,000
90 sec / 40 tph
8,000
12,000
16,000
24,000
Max Passengers per hour per direction
If the system is run with 4-car trains ( 52m long, 400 people ) then each line has the capacity over double one of the major Auckland motorways such as the Western or Southern.
Line 1 – A North/South Metro line from Takapuna to the Airport
This line would start from Takapuna run under the CBD and connect to the Airport in the South.
The line would be grade separated above the road as much as possible since this is cheaper than under-grounding. It would be underground though the central city however.
Total length would be around 28km of which around 6.2km would be underground. Cost would be something like $15b
Northern Section
This would be completely overhead and mainly above roadways. It would start from a station at Takapuna and then another station at the Existing Busway station of Akoranga.
The route would then go between the motorway and the sea until it reaches a tunnel across the harbour near Northcote Pt.
See section below for discussion as to the advantages and disadvantages of a tunnel vs a bridge for crossing Waitemata Harbour.
A route to Takapuna avoids duplicating the existing busway. Going off the 2024 bus statistics around 20% of the busway passengers go to Takapuna and Milford and it is likely some more would change from the bus to metro at Akoranga station if the Metro better served the southern part of their journey.
I have mapped out some possible extensions to this line but there are several other options.
A natural extension to this line would be a line to the North Shore Hospital and then Milford.
A line to Northcote and Birkenhead could also be built, although this line unfortunately goes the wrong way for Northcote and Birkenhead people going into the city.
Later lines might go down Wairau Rd to the Wairau Valley
City Section
The first station will be under the eastern end of Victoria Park. Ideally it should have entrances on the far sides of Fenshaw, Halsey and Victora Streets so passengers do not have to cross busy roads to reach it.
The Te Waihorotiu CRL station is apparently already future-proofed with space for a North/South line. The station will effectively be the centre of the Auckland System. There should also be a surface Light Rail line nearby on Queen Street.
The University station would be quite deep (because the line would be under Queen Street and the Grafton Valley Motorway) and probably be an elevator-only station.
I’ll cover how lines intersect later
The Southern Isthmus
South of the University the line has a station on the corner of Park Road to serve the Hospital, The Grafton Campus and nearby area. This station may be deep enough to also be elevator-only.
The line comes out of it’s tunnel just after the domain and is now elevated until it reaches the Airport.
The first station is on Carlton Gore road to serve Northern Newmarket. Then there is Station in central Newmarket connected to the existing rail station.
South of Newmarket the line will travel above Manukau Rd and continue South through Royal Oak and Onehunga.
Possible stations could be (at roughly 1km intervals):
Near corner Manukau and Great South Road
Corner of Manukau Rd and Ranfurly Road
Corner of Manukau Rd and Queen Mary Ave (Alexandra Park, Green Lane West Rd)
Corner of Manukau and Pah Roads
Royal Oak Mall
Corner of Manukau Rd and Trafalgar St ( optional / future-proofed )
Onehunga Mall Road near Grey Street
Onehunga Station
Mangere Section
The southernmost section crosses the Mangere harbour near the current bridges (No special bridge should be needed since it will be fairly low) and has a station at Mangere Bridge Village just South of the crossing.
The line then continues south along the Coronation Rd, McKenzie Rd and Bader Drive with the provision of a future station near Miller Road.
The station follows Bader Drive over the motorway to a station in Mangere town Centre. It then cuts over some houses (which will need to be purchased) back to the motorway and follows it South.
I’ve future proofed a station in the airport industrial area after which the line goes underground between Landing Drive and Ihumatoa Road for about 1km to a station under the airport.
The Depot for the Line would probably be best placed somewhere between the Airport and Mangere Town Center Station.
Bridge vs Tunnel for the Waitemata Harbour crossing
The plan currently has the line using a tunnel. This is probably about $1b more expensive than a bridge and makes it very difficult to provide a walking or cycling option.
The reason for this is that currently the Upper Harbour (West of the Auckland Harbour Bridge) has Chelsea Sugar Refinery and the Kauri Point Armament Depot. Both of these much be reachable by large ships. This requires a clearance of any bridge over the water to be similar to the current bridges 43 metres.
Since trains have problems with gradients much over 3% this would require over 1km of climb to reach which is almost impossible to fit south of the ship channel.
If the Sugar Refinery and Ammunition Depot can be moved then a lower bridge quickly becomes the best option. With a saving of over $1b it might be better to pay for them to move. However I have kept things as a bridge for now.
CBD stations and line intersections
This maps shows the other lines including the existing lines, a Queen St Light Rail and my proposed Western line.
The Victoria Park station as well as serving the immediate area supports transfers to the Western Line to get to lower-Queen Street and transfer to College Hill and Northcote buses
The Te Waihorotiu Station allows access to Aotea Square area and transfers to the CRL and Light Rail
The University Station serves the Universities and allows transfers to the Western line and Symonds Street Buses.
Southern Branches and Other Lines
As the lines gets further South the demand on the single line will be reduced. So I propose that the line eventually branch just South of Newmarket
The new line would go down Great South Road as far as the existing Penrose Station and then East along Penrose Rd to meet the Sylvia Park station. It would then go East to Pakuranga and down Ti Rakau Dr to Botany. The existing Greenlane and Remuera stations could perhaps be replaced by Stations on the line
Because Light Metro can handle very high frequency, capacity on both branches would be high. For example trains could be every 2 minutes in the central areas and every 4 minutes on the branches
I’ve sketched out some later lines mainly to make sure the planned line has room for growth.
The first is a line from Mangere Town Center to Botany that goes though Papatoetoe and Otara.
The other is a cross town line that Starts in Point Chevalier and Follows Carrington, Mt Albert, Mt Smart and Great South Roads to Manakau City.
Penrose station would be a natural intersection point for two of the lines (and the existing heavy rail) and could be upgraded to be a major transfer station.
Keeping the cost down
It is important to keep the cost of the line down as much as possible to improve it’s chances of being built. Especially the urge must be avoid to create expensive monumental stations or under-grounding more sections to avoid perceived disruption.
I propose the following measures
Elevated Line instead of Underground where possible.
A standard simple design for elevated stations. Cheap colour and art can provide differentiation for a small percentage of the cost
Simple underground stations
Leaving space for some stations to be built later
Relatively small elevated stations. Perhaps only with 60m (4 car) platforms being initially built but space left for larger additions later.
Driverless operation
Using Standard off-the-shelf Train systems that are already deployed elsewhere with minimal changes
Note that driverless operation allows frequent trains which in turn allow shorter trains which means smaller cheaper stations.
Costing
I put my costs are what I consider realistic New Zealand levels. Some countries are able to build for less but I’ve listed what I hope New Zealand can build for.
$1b/km underground lines
$300m/km for elevated
Stations: $25m elevated, $250m underground
$1b/km + $500m extra for Harbour Tunnel
North/South Line length by type of track
4.1 km Overhead from Takapuna to the Tunnel
A 2.4 km tunnel across the Harbour
A 3.7 km tunnel under the CBD
8.6 km to the northern shore of Mangere Inlet
7.7 km overhead across the inlet and South
1 km underground near the airport
Total
4.7 km underground
2.4 km Harbour tunnel
20.4 km overhead
Total cost
4.7 km underground at $1b/ km = $4.7b
2.4 km Harbour Tunnel = $2.9b
20.4 km of overhead line at $300m/km = $6.1b
13 overhead stations at $25m each = $325m
5 underground stations at $250m each = $1250
Total = 15.2b
General observations and conclusions
Travel times for this sort of Metro are around 30km/h including stops although this line has fewer stops than most and some long stretches so should be a bit faster. Assuming 30km/h we get:
Airport to Te Waihorotiu station 19.4km = 38 minutes
Takapuna to Te Waihorotiu station 8.1km = 16 minutes
Currently the Airport takes around 1h 30m via public transport and 40 minutes for the Skydrive private Airport bus outside of peak times. The bus from Takapuna takes 20-25 minutes. Remember that the metro will have very high fequency so waiting for the next train will only be a couple of minutes.
I’ve tried to make the route realistic and useful. As far as I can tell all the climbs are within the capacity of a typical metro system. However some of the corners may be a little tight and additional space may be needed.
While only a small proportion of the passengers will travel to and from the airport I think the service will be great for this. Some people do express concern about room for luggage but riders manage on other systems around the world.
I think that this line and the Western line has a great potential to improve transport across Auckland. It will take pressure off the Northern Busway and also add huge capacity to the South West and Airport.
My next article will cover my proposal for a Western Line
Changes since previous version
General
I’ve made 3 stations on the line optional to save cost and increase speed
North Shore
Instead of replacing the Northern busway I’ve updated the line to go to Takapuna and eventually Milford instead. This will be around 1.7km from Akoranga Station rather than 10km so it should say $2-3 billion from the initial build and mean that we augment the Northern Busway rather than replace it..
I’ve included a few possible routes but there are a lot of options both for the initial route into Takapuna and future lines.
Central City
I’ve replace the Wynyard and Victoria stations with a single station under the east of Victoria Park. It would also have a similar service area to the two stations.
I’ve also rerouted the end of the Western Line to go along Fenshaw St rather than across the Viaduct Basin
Auckland Hospital
My original plan had the line going South from the University, under the motorway and Museum and emerging on the North of Newmarket
However skipping the hospital seems a bad idea. It is a huge trip generator not just for the hospital but for the Grafton Campus and other businesses and housing nearby.
So I’ve updated the route to have a station under the corner of Park road and the line emerging on Carlton Gore road with a station near the bottom of that road.
Mangere
I’ve changed Mangere town centre to be directly on the line instead of a short branch. This does mean the line goes through housing to get back on the motorway.
A fun romp though the unexpected 3rd Act of 60s and 70s Music Stars since 1985. Full of amusing stories delivered with Hepworth’s usual witty style 4/5
An insider’s stories of Facebook (and a Shark attack). Lots of nuts stuff and good yarns the reflect pretty negatively. Although the author seems too good to be true. 4/5
It is appropriate, on World Quantum Day, to talk about quantum computing and quantum computers, as the two are often confused. Quantum computing is any method to generate quantum effects whereby qubit states can exist in superposition (o,1, both) rather than binary states (0,1). Binary states are represented in classical computing in low-level software as logical 0s and 1s but in hardware as high and low-voltage states.
The typical system to do quantum computing, or at least simulate it, is usually High Performance Computing (HPC). That works, it's a proven technology that has a rate of return of $44 per $1 invested - and higher when COVID research is considered. The development of HPC clusters with message passing is one of the most successful technological developments in computing in the last thirty years.
In contrast, a quantum computer directly uses a quantum mechanical system and requires appropriate specialised hardware. For example, GENCI in France uses a photonic computer, LRZ in Germany uses superconducting qubits, PSNC in Poland uses trapped ions, etc. David P. DiVincenzo offers the most significant physical challenges that face quantum computers, regardless of what technology is used; these include scaling qubits, initialisation of values, developing a universal gate for the construction of a quantum operation, developing gates that are faster than decoherence from a quantum state due to environmental interactions, and reading qubits (especially considering that can alter the quantum state).
As a result, classical computers outperform quantum computers in all real-world applications. Not only that, there is a serious issue of whether quantum computers will ever be able to outperform classical computers. Mikhail Dyakonov points out that the rudimentary qubits used in quantum computing systems is insufficient for useful calculations.
"Experts estimate that the number of qubits needed for a useful quantum computer, one that could compete with your laptop in solving certain kinds of interesting problems, is between 1,000 and 100,000. So the number of continuous parameters describing the state of such a useful quantum computer at any given moment must be at least 21,000, which is to say about 10^300. That's a very big number indeed. How big? It is much, much greater than the number of subatomic particles in the observable universe."
The promise of quantum computers is, of course, very significant in theory. In theory, it can perform some calculations incredibly fast, and the larger the task, the more impressive the result, to the extent that common secure encryption systems could be broken, as well as the more prosaic use in quantum simulations. In reality, the physical implementation has been more than challenging, to put it mildly. Classical computers, in principle, can solve the same problems as a quantum computer can, in principle solve as well. For a classical computer the problem is the sheer quantity of time that is required. For quantum computers, the problem is the implementation in reality. For the time being, and for the foreseeable future, it seems that quantum computing will continue to be done on classical computers.
As was flagged earlier and at the AGM, we need to go through a process of amending our constitution if we want to remain as a not for profit.
The deadline for this process is 30 June 2025
Thank you Russell for the hard work in preparing the necessary changes as a series of pull requests. Thank you to everyone who reviewed and provided feedback on the changes.
Before we vote, is there anything anyone wants to bring up for discussion?
[No issues raised]
Question: Do we have a quorum?
Answer: Yes and everyone in the meeting is qualified to vote as a member of Linux Australia.
We have had nine proxies registered. We will process the vote via a Zoom poll and then add the proxies. It requires a 75% vote in favour for the change to pass.
My wife and I were with Optus for our mobile phone service since approximately the dawn of time, but recently decided to switch to another provider. We’d become less happy with Optus over the last few years after a data breach in 2022, an extended outage in 2023, and – most personally irritating – with them increasing the price of our plan despite us being under contract. Yes, I know the contract says they’re allowed to do that given 30 days notice, but they never used to do that. If you signed up for a $45 per month (or whatever) plan for two years, that’s what you paid per month for the duration. Not anymore. To their credit, when my wife lodged a complaint about this, they did end up offering us a 10% discount on our bill for the next 24 months, which effectively brought us back to the previous pricing, but we still maintain this practice just isn’t decent, dammit.
The question was: which provider to switch to? There are three networks in Australia – Telstra, Optus and Vodafone, so you either go with one of them, or with someone who’s reselling services on one of those networks. We already have a backup pre-paid phone with Telstra for emergencies, and so preferred the idea of continuing our main service on some other network for the sake of redundancy. iiNet (our ISP) repeatedly sent us email about nice cheap mobile services, but they were reselling Vodafone, and we’d always heard Vodafone had the worst coverage in regional Australia so we initially demurred. A few weeks ago though, iiNet told us they’d doubled their network coverage. It turns out this is due to TPG (iiNet and Vodafone’s parent) striking a deal with Optus for mutual network access. This all sounded like a good deal, so we ran with it. We received a new SIM each in the mail, so all we needed to do was log in to the iiNet toolbox website, receive a one time-code via SMS to confirm the SIM port, then put the new SIM in each of our phones, power cycle them and wait to connect. We decided to do one phone at a time lest we be left with no service if anything went wrong. I did my phone first, and something did indeed go wrong.
After doing the SIM activation dance, my phone – an aging Samsung Galaxy A8 4G which Optus had given me on a two year contract back in 2018 – said it was connected to iiNet. Mobile data worked. SMS worked. But I could not make or receive calls. Anyone I tried to call, the phone said “calling…” but there was no sound of a phone ringing, and eventually it just went >clunk< “call ended”. Incoming calls went straight to voicemail, which of course I could not access. Not knowing any better I figured maybe it was a SIM porting issue and decided to ignore it for a day in the hope that it would come good with time. Forty-eight hours later I realised time wasn’t working, so called iiNet support using this thing:
Inscribed on the back is “This phone remains the property of Telecom Australia”.
The extremely patient and courteous Jinky from iiNet support walked me through restarting my phone and re-inserting the SIM (which of course I’d already done), and resetting the network settings (which I hadn’t). She also did a network reset at their end, but I still couldn’t make or receive calls. Then she asked me to try the SIM in another handset, so I swapped it into our backup Telstra handset (a Samsung Galaxy S8), and somewhat to our surprise that worked fine. We double checked my handset model (SM-A530F) against the approved devices list, and it’s there, so it should have worked in my handset too… Alas, because we’d demonstrated that the SIM did work in another handset, there was nothing further Jinky could do for me other than suggest using a different handset, or finding a technician to help figure out what was wrong with my Galaxy A8.
After a lot of irritating searching I found a post on Whirlpool from someone who was having trouble making and receiving calls with their Galaxy A8 after the 3G network shutdown in late 2024. The interesting thing here was that they were using an Optus-branded but unlocked phone, with a Testra SIM. With that SIM, they couldn’t make or receive calls, but with an Optus SIM, they could. This sounded a lot like my case, just substitute “iiNet SIM” for “Testra SIM”. The problem seemed to be something to do with VoLTE settings? or flags? or something? That are somehow carrier dependent? And the solution was allegedly to partially re-flash the handset’s firmware – the CSC, or Country Specific Code bits – with generic Samsung binaries.
So I dug around a bit more. This post from Aral Balkan about flashing stock firmware onto a Galaxy S9+ using the heimdall firmware flashing tool on Ubuntu Linux was extremely enlightening. The Samsung Updating Firmware Guide on Whirlpool helpfully included a very important detail about flashing this stuff:
Use CSC_*** if you want to do a clean flash or
HOME_CSC_*** if you want to keep your apps and data. <== MOST PEOPLE USE THIS
The next question was: where do I get the firmware from? Samsung have apparently made it extremely difficult to obtain arbitrary firmware images directly from them – they’re buried somewhere in encrypted form on Samsung’s official update servers, so I ended up using samfw.com. I downloaded the OPS (Optus), VAU (Vodafone) and XSA (unbranded) firmware archives, matching the version currently on my phone, extracted them, then compared them to each other. The included archives for AP (System &Recovery), BL (Bootloader) and CP (Modem / Radio) were all identical. The CSC (Country / Region / Operator) and HOME_CSC files were different in each case. These are the ones I wanted, and the only ones I needed to flash. So, as described in the previously linked posts, here’s what I ended up doing:
Installed heimdall on my openSUSE laptop.
Extracted the HOME_CSC files (cache.img and hidden.img) from the XSA firmware archive.
Plugged my phone into my laptop, and rebooted the phone while somehow managing to hold down all three volume up, volume down and power buttons to get it into Download mode.
Ran heimdall flash --CACHE cache.img --HIDDEN hidden.img and waited in terror for my handset to be bricked.
The procedure worked perfectly. VoLTE – which wasn’t previously active on my phone – now was, and I could make and receive calls. VoLTE stands for Voice over Long-Term Evolution, and is the communications standard for making voice calls on a 4G mobile network.
It was at this point that the woefully untrained infosec goblin who inhabits part of my brainstem began gibbering in panic. Something along the lines of “what the hell are you doing installing allegedly Samsung firmware from a web site you found listed in a random forum post on the internet?!?”
I believed from everything I’d read so far that samfw.com was reputable, but of course I had to double-check. After an awful lot of screwing around on a Windows virtual machine with a combination of SamFirm_Reborn (which could download Samsung firmware once I tweaked SamFirm.exe.config to not require a specific .NET runtime, but couldn’t decrypt it due presumably to that missing .NET runtime), and SamFirm (which can’t download the firmware due to Samsung changing their API to need a serial number or IMEI, but could decrypt what I’d downloaded separately with SamFirm_Reborn), I was able to confirm that the firmware I’d downloaded previously does in fact match exactly what Samsung themselves make available. So I think I’m good.
The SIM activation dance on my wife’s phone – a rather newer Samsung Galaxy S21 Ultra 5G – went without a hitch.
Neuro-divergence, encompassing conditions such as autism spectrum, ADHD, and sensory processing, can profoundly influence how individuals perceive and respond to their bodily signals.
While neurotypical individuals generally recognise and respond to hunger, thirst, and satiety cues with relative ease, neuro-divergent individuals often face unique challenges in this area. Understanding these challenges is crucial for fostering empathy and supporting effective strategies for well-being.
This article is written so it is directly readable and useful (in terms of providing action items) for people in your immediate surroundings, but naturally it can be directly applied by neuro-spicy people themselves!
Hunger and Thirst Cues
For many neuro-divergent people, recognising hunger and thirst cues can be a complex task. These signals, which manifest as subtle physiological changes, might not be as easily identifiable or may be misinterpreted.
For instance, someone on the spectrum might not feel hunger as a straightforward sensation in the stomach but instead experience it as irritability or a headache. Similarly, those with ADHD may become so hyper-focused on tasks that they overlook or ignore feelings of hunger and thirst entirely.
Sensory Processing and Signal Translation
Sensory processing issues can further complicate the interpretation of bodily signals. Neuro-divergent individuals often experience heightened or diminished sensory perception.
This variability means that sensations like hunger pangs or a dry mouth might be either too intense to ignore or too faint to detect. The result is a disconnection from the body’s natural cues, leading to irregular eating and drinking habits.
Satiety and Fullness
Recognising satiety and fullness presents another layer of difficulty. For neuro-divergent individuals, the brain-gut communication pathway might not function in a typical manner.
This miscommunication can lead to difficulties in knowing when to stop eating, either due to a delayed recognition of fullness or because the sensory experience of eating (such as the textures and flavours of food) becomes a primary focus rather than the physiological need.
Emotional and Cognitive Influences
Emotions and cognitive patterns also play significant roles. Anxiety, a common experience among neuro-divergent individuals, can mask hunger or thirst cues, making it harder to recognise and respond appropriately.
Additionally, rigid thinking patterns or routines, often seen with autism spectrum, might dictate eating schedules and behaviours more than actual bodily needs.
Strategies for Support
Understanding these challenges opens the door to effective strategies and support mechanisms:
Routine and structure: Establishing regular eating and drinking schedules can help bypass the need to rely on internal cues. Setting alarms or reminders can ensure that meals and hydration are not overlooked.
Mindful eating practices: Encouraging mindful eating, where individuals pay close attention to the sensory experiences of eating and drinking, can help in recognising subtle signals of hunger and fullness.
Sensory-friendly options: Offering foods and beverages that align with an individual’s sensory preferences can make the experience of eating and drinking more enjoyable and less overwhelming. This is a really important aspect!
Environmental adjustments: Creating a calm, distraction-free eating environment can help individuals focus more on their bodily cues rather than external stimuli.
Education and awareness: Educating neuro-divergent individuals about the importance of regular nourishment and hydration, and how their unique experiences might affect this, can empower them to develop healthier habits. This is, of course, more a longer term strategy.
Understanding the complex interplay between neuro-divergence and bodily signals underscores the importance of personalised approaches and compassionate support.
By acknowledging and addressing these challenges, we can help neuro-divergent individuals achieve better health and well-being!
The standard computing model uses unithreaded instructions and data with automation through looping and conditional branching. Automation is encouraged as it results in the computer doing the work that it is designed for. However, this can be inefficient when using a multicore system. An alternative in HPC systems is to make use of job arrays, which use a job to allocate resources to sub-jobs which can be individually controlled, whether directed toward instruction sets or datasets. Further, job arrays can be combined with job dependencies, allowing for conditional chains of job submission and runs. Finally, job arrays can be simulated through the use of heredocs with looped submission. This may even allow more familiar control with shell scripting.
This slidedeck is derived from a presentation to the Univerity of Melbourne's "Spartan Champions" group on March 7, 2025.
I’ve been using virtio-serial for communications between Linux hypervisors and guest virtual machines for ages. Lots of other people do it to — the qemu guest agent for example is implemented like this. In fact, I think that’s where I got my original thoughts on the matter from. However, virtio-serial is actually fairly terrible to write against as a programming model, because you’re left to do all the multiplexing of various requests down the channel and surely there’s something better?
Well… There is! virtio-vsock is basically the same concept, except it uses the socket interface. You can have more than one connection open and the sockets layer handles multiplexing by magic. This massively simplifies the programming model for supporting concurrent users down the channel. So that’s actually pretty cool. I should credit Kata Containers with noticing this quality of life improvement nearly a decade before I did, but I get there in the end.
The virtio-vsock model is only a little bit weird. The “address” for the guest virtual machine is a “CID” (Context ID). The hypervisor process is always at CID 0, CID 1 is reserved and unused, and CID 2 is any process on the host which is not the hypervisor. You can also use port numbers like you would with IP, which means you can have multiple services down a single vsock channel if you’d like. I haven’t looked deeply into the history of vsock, but pages like this one make me think it originated with VMWare.
So let’s write some code. All of the examples I could find (this gist, or the page linked in the previous paragraph) have the server on the host, and then the client being inside the guest virtual machine, but I want the exact opposite. It wasn’t as hard as I thought it would be to figure out, especially once I found this very helpful gist about how to lookup the CID from inside the guest virtual machine.
(As an aside, my life would be much worse if github took the gist feature offline. There is so much useful random stuff out there in gists.)
So here’s our server, which runs inside the virtual machine:
import fcntl
import socket
import struct
PORT = 1025
# Lookup our CID. This is a 32 bit unsigned int returned from an ioctl
# against /dev/vsock. As best as I can tell the empty string argument
# at the end is because that is used as a buffer to return the result
# in. Yes really.
with open('/dev/vsock', 'rb') as f:
r = fcntl.ioctl(f, socket.IOCTL_VM_SOCKETS_GET_LOCAL_CID, ' ')
cid = struct.unpack('I', r)[0]
print(f'Our CID is {cid}.')
s = socket.socket(socket.AF_VSOCK, socket.SOCK_STREAM)
s.bind((cid, PORT))
s.listen()
conn, (remote_cid, remote_port) = s.accept()
print(f'Connection from {remote_cid} on with remote port {remote_port}')
while True:
buf = conn.recv(1024)
print(f' in: {buf}')
if not buf:
print('Nothing received, exiting')
break
print(f'out: {buf}')
conn.sendall(buf)
conn.close()
print('Done')
And here’s our client, which runs on the host OS. Note that the CID is hard coded here because I specified it when I created the virtual machine, it just happens to be my favorite 32 bit unsigned integer:
import socket
CID = 347338050
PORT = 1025
STRINGS = [
b'Hello World!',
b'Banana',
b'Duck'
]
s = socket.socket(socket.AF_VSOCK, socket.SOCK_STREAM)
s.connect((CID, PORT))
for out in STRINGS:
s.sendall(out)
print(f'out: {out}')
buf = s.recv(1024)
if not buf:
print('Nothing received, exiting')
break
print(f' in: {buf}')
s.close()
print('Done')
From Friday 24th January to Sunday 26th January 2025 I attended the OzMoot 2025 conference in Melbourne.
OzMoot is a small conference centered around the works of J.R.R Tolkien and related topics. It is run by Hern Ennorath (The Australian Tolkien fan organisation) in partnership with Signum University who do various activities including running similar events around the world.
Overview
Around 30 people attended in person with a similar number online. The venue was a community hall. Cost was $US 100 per person for the two and a half days of the conference.
The programme mostly consisted of talks on various topics ( Scroll down here to see the schedule ) with coffee/biscuits for morning and afternoon tea and a break for lunch which most people took at the nearby cafes (or brought food back to the venue). In the evening there were two dinners (one at a restaurant and another at the home of an attendee) plus there was an ad-hoc dinner on the last day some attended.
When I saw the “mostly talks” there were several events that were not straight presentations. They included several talks that included music (as per the theme of the conference) plus straight musical performances, a costume parade, Tolkien readings and a trivia competition.
The Hall also had tables setup. One with books (and other items) for sale, a second with collectables displayed and a 3rd with a jigsaw puzzle (which we collectively did not finish)
The event was Hybrid with streaming via Zoom and an active Slack for the duration of the event.
Items for sale
Collectables Display
Impressions
The conference was described as “In the grey area between fan convention and academic conference” which is pretty accurate. Many of the talks are quite academic although by no means all of them and the talks are mostly accessible even if you are only a casual fan (or been dragged along by your Mum in two cases this year).
You note that not all the talks are directly Tolkien related. eg the Keynote was analyzing Rap/HipHop Music.
“Tolkien Professor” Corey Olsen analyzing Rhyming in Rap Music
This conference was the third I’ve attended. I went to 2023 online and attended OzMoot 2024 in Sydney in person.
The whole event is great and the people are very welcoming. The attendees are a wide range of ages and have lots of interests and skills outside the world of Tolkien.
I would recommend the conference if you are interested in Tolkien and in Australia or New Zealand. If you want to start off slow I’d suggest attended one of the Moots online. They mostly last a day and cost around $US25. Signum also does several free weekly streams/podcasts and paid online courses.
Next year’s OzMoot is planned for late-January 2026 in Canberra and there are tentative plans for 2027 to be held in Wellington. I hope to attended both events.
Since 2016, Facebook Messenger has allowed the option for end-to-end encrypted messages, and in 2023, they were established as the default.
This has caused some issues with people exporting Messenger data for archival or viewing purposes. It is a lot quicker to search for information when the data is local, and it is better practice to do so.
Encrypted Facebook Messenger data can be downloaded by selecting "Privacy & safety" on the Facebook menu, then "End-to-end encrypted chats", then "Message storage", and finally "Download secure storage data".
When the file is ready, it will provided as a zip file that contains various binaries in a "media" directory and well-formatted JSON files for each message chat for current Friends.
Despite the formatting, JSON files are less than optimal for humans to read. The "Lament" Python script makes use of pandas, json, sys, and datetime modules. Simply copy it into your messages directory, where all the JSON files are located and run:
$ python3 lament.py
It will then output a formatted HTML table that can be opened by a browser of your preference. The table includes a human-readable date (rather than the UNIX timestamp), the sender, the message, reactions, and a reference to any media.
The format and logic of the Python script are simple enough that it can be easily extended to other JSON data from Messenger and can be adapted to other JSON data files.
2025 was the 3rd Everything Open (EO) to be held and around 300 people attended. The Conference opened each day with a keynote and then split into 3 streams of talks plus a tutorial stream. Talks range fairly widely, the official blurb is a “conference focused on open technologies, including Linux, open source software, open hardware and open data, and the communities that surround them“
The venue was the Adelaide Convention Centre which had plenty of room and was nice enough. They main train lines for Adelaide ran under it with around 8 tracks under the venue. There were good food options a few minutes walk away since the venue is close to the Adelaide CBD.
Accommodation was fairly good. I got a hotel for $150/night about 10 minutes walk away that was near restaurants etc.
Content and attending
I really enjoyed the keynotes this year. All three speakers were interesting and and had great delivery. I also felt there talks were all good and there are several I missed that I’d like to catch-up if/when the videos are out.
I publish my (rough) notes from talks I attend to this blog. A list of here
Unfortunately I’m still masking (as were about 5% of attendees) so I probably didn’t participate in the Hallway track as much I would in the past. It was also fairly small due to relatively small numbers at the conference (see below)
The only organised evening event was the Penguin dinner at the Zoo. Unfortunately we didn’t get to see animals, just the food venue (drinks and chat followed by dinner)
Thoughts on the conference Format and Future
While EO attracted around 300 people which was almost double last year (held in the fairly remote city of Gladstone) but still less than what half a typical LCA attracted before Covid.
Unfortunately EO is still a step down from LCA. There were very few attendees from outside Australia and New Zealand. Part of this is due to disruption of conference going during COVID and part due to the general economic conditions but I think there were some other factors
At LCA Miniconfs were a good way to attract people and provide targeted content. People would come for the Kernel, GLAM or Sysadmin Miniconf (disclaimer I helped run the latter) and stay for the rest of the conference. They could tell their boss they were going to the “Work-related Miniconf” at LCA and staying for the rest.
The lack of Miniconfs also meant the conference was less nimble. While several talks were about LLMs and AI, in the past a LCA would probably have had 1-2 days of Miniconfs devoted to this hot topic (perhaps one day technical for users and a 2nd day for users and policy). Eg in 2020 there was a Kubernetes orientated Miniconf.
The conference being only 3 days and 3+1 streams rather than 3 days of 5+1 (plus 2 days of Miniconfs) seen at later LCAs also means people get less for their buck. Especially since travel will make up a significant cost for many attendees.
The inclusive EO brand also trying to reach out to a broader group means that the conference is less attractive to a technical user. The Irony is of course that LCA was a nominally technical conference with a lot of non-technical content while EO is a branded as a broad conference that is still probably 75% technical talks.
I’ll probably come back next year if the event is held. However the event had yet to be arranged due to lack of a bid. However a group was formed after the this year’s conference and it is likely that an event will happen in Canberra in 2026.
The Linux Australia AGM covered several problems with the conference (see The Linux Australia 2025 AGM video ) including difficulty finding people to run it, problems finding sponsors and the format. Questions were asked about bringing Miniconfs and problems with them were highlighted.
Overall it is difficult to tell where things are going. The conference is fairly successful but struggling to be sustainable. Personally I am not sure on the best path. Perhaps splitting the conference into two could work. Something like 2 days of Linux.conf.au, one day of Miniconfs and then 2 days of EO. But anything would required people to volunteer to help which is difficult right now.
This is the fifth murderbot book and it’s a fun read just like the rest. Unfortunately, it’s also really short just like most of the others and I find that the story is therefore just a bit simple and two dimensional. It is nice that the story isn’t just a repeat of previous entries in the series, although I would say that this one is relatively free standing in that it doesn’t progress the overall story arc. That said, no regrets reading this one.
Fugitive Telemetry
Martha Wells
Fiction
Tordotcom
April 27, 2021
128
Aotearoa New Zealand has run eResearch symposiums and conferences since 2010, with the 2025 conference held in Christchurch, co-hosted with Genomics Aotearoa, New Zealand eScience Infrastructure (NeSI) and REANNZ. The first day, a "Carpentries Connect" event, was held at Canterbury University, whilst the main conference was held at the "Chateau on the Park" motel. The conference is focused on technological tools and processes that aid researchers; it is notable that most of the attendees are in the fields of technology deployment, support, management, education and training; they are often professionals who are concurrently researchers or come from a research background.
The Carpentries Connect day featured the Executive Director of the Carpentries, Dr. Kari L. Jordan, who spoke passionately on the importance of the Carpentries to improve the computational skills of researchers and the process of continuous improvement, dedication to evidence-based andragogy, and expansion over the last twenty-seven years. This has led to over 100,000 people receiving instruction and widespread adoption throughout the world and, in particular, in New Zealand. Of particular note was the annoucement that the HPC Carpentry program was now sufficiently developed - after many years - that deployment was expected this year. Of note, Dr. Tom Pollard from Massachusetts Institute of Technology (MIT), USA and Technical Director, delivered a fascinating talk on "Responsible Machine Learning" and what "irresponsible" machine learning looks like!
The conference proper consisted of three days of keynotes and concurrent sessions, about 75 in total. It is, of course, impossible to give a summary of all events that give them justice, but rather remarks are given on a few presentations that especially stood out from my own perspective. These must include the keynotes from Dr Giuseppe Barca from the University of Melbourne on quantum chemistry, drug development, and the use of Frontier, the second most powerful public supercomputer in the world, and especially their development of GPU-based quantum chemistry software, linear scaling and quantum potential and ML training with multi-layer molecular mechanics.
Another was Professor Rick Stevens of the University of Chicago and Argonne National Laboratory, who illustrated the explosive development in AI in the past few years and how planning was already underway for further massive investment in LLMs in the next few years. His comments matched a pithy remark from April Neoh of NVIDIA/HPE earlier in the conference that model innovations were "learning faster than we can learn what to do with it". He also made the observation that there was increasing pressure for hardware to move to mixed precision for performance, which matched Barca's earlier remarks that the future will increasingly have domain-specific architectures.
A third presentation of note was that from Amber McEwan, Chief Executive Officer at REANNZ, who spoke on the merge of NeSI with that body, following the Ministry of Business, Innovation, and Employment report proposing the merger in 2022 and the directive for implementation. It was, as can expected, a carefully-worded presentation that outlined the process for integration, the need for consolidation of eResearch infrastructure, and the purpose to attract and retain talent in the eResearch workforce. The initial stage, also as can be expected for these two mature organisations, is a "lift and shift" approach that will be complete by July 2025.
My own presentation, "HPC Bioinformatics Education: The University of Melbourne Experience" drew from a large body of previous work on HPC education. An outline of the UoM and precinct environment for bioinformatics was provided, along with general andrological approaches, the University of Melbourne's HPC onboarding process, particular needs for bioinformaticians, and empirical outcomes were all provided. The presentation was well-received, with ongoing interest and feedback. I must also note that the talk dovetailed quite nicely into the one that was followed by Paul Gardner of the University of Otago, who, following exhaustive test cases, differentiated bioinformatic tools across the dimensions of speed and accuracy and concluded that sustained development was the best metric for determining the most effective software.
Understandably, interest in developing eresearch skills featured highly, with several presentations returning to this subject of discussion with an extensive BoF dedicated to the topic from the Carpentries groups, NeSI, Genomics Aotearoa, and the individual universities. Another item of interest was how extensive the "Spartan architecture" of hybrid HPC extended with cloud compute ("FlexibleHPC" is their preferred term) and with a lowered barrier-to-entry with Open OnDemand has been adopted in New Zealand, both in terms of the national system and smaller systems at Otago University and the University of Canterbury. The national system, following upgrades, will have 20K cores using AMD Genoas plus existing AMD Milan and Intel Broadband processors.
Overall, eResearchNZ continues to be an exceptional conference that brings together those on the cutting edge of high performance and high throughput computing, the people who look after such systems, and those who provide a bridge for researchers to access and understand the technology. After conferences that, due to COVID circumstances, were held in virtual environments, to have face-to-face meetings again allowed for excellent networking opportunities and free conversation and elaboration on presentations. Once again, New Zealand can be justly proud of its ability to "punch above its weight" and put on a world-class eResearch conference.
This is the third book in this series, coming after Children of Time and Children of Ruin. While I really liked the first of the books in the series, the second felt weaker. While this one doesn’t review as well as the second I think it’s actually a stronger book. Whilst sometimes a bit repetitive I think the ideas presented here are novel, and the book does a good job of finding a new way of discussing the tensions that refugees and mass immigration create for societies.
This book is also an interesting combination of science fiction and fantasy — the familiar territory of a failing colonization ship sent out on a hope and a prayer, and then a fantasy story about a little girl trying to save her family and a group of strangers come to town.
Overall, I enjoyed this book.
Children of Memory
Adrian Tchaikovsky
Fiction
Tor Books
July 27, 2023
480
"Whoever has seen the universe, whoever has beheld the fiery designs of the universe, cannot think in terms of one man, of that man's trivial fortunes or misfortunes, though he be that very man."
-- Luis Borges
Titan is the largest moon of Saturn, about 1.2 billion kilometres from Earth. Discovered in 1655 by Christiaan Huygens, the dense opaque atmosphere prevented any understanding of Titan's surface for many years. It is the only moon known to have an atmosphere with a greater density than Earth and the only known object in space that has stable bodies of surface liquid.
Knowledge of Titan was greatly improved by the Cassini-Huygens probe-lander, a joint effort by NASA, the ESA (European Space Agency), and the ASI (Agenzia Spaziale Italiana). It was launched on October 15, 1997. Travelling to Saturn included flybys of Venus, Earth, asteroids, and Jupiter.
The Huygens lander module travelled with Cassini until its separation from the probe on December 25, 2004; Huygens landed by parachute on Titan on January 14, 2005. For its own part, Cassini made passes through the gaps between Saturn and its inner rings before going into Saturn's upper atmosphere, where it burned up.
The Huygens lander discovered that Titan has a thick atmosphere that's 95% nitrogen and 2% methane. The surface has rivers, lakes, and even seas of the hydrocarbons methane and ethane.
The landing is something that, to this day, I watch in awe.
I got married. I moved into the flat. Companies have gone up and down, like life.
170 days on the road, 308,832km travelled, 38 cities, and 16 countries. I have never travelled this little in recent life, but maybe the whole getting married thing (planning a wedding is no mean feat), and sorting the flat out (dealing with incompetent interior designers, sorting things there, etc.), caused this?
It is 2025, and I’m actually planted in Kuala Lumpur, not having done an end of year trip, to usher in the New Year somewhere else. I started the year in Paris, and I ended the year in Kuala Lumpur, tired, and maybe a bit burnt out.
Working hard to get back into the grind; don’t get me wrong, I’ve been doing nothing but grinding, but c’est la vie.
The end of this year marks my seventeenth year working in high performance computing and my ninth at the University of Melbourne in this role. When I compare this to previous years there have been some notable changes in the technology and the system I am primarily involved with (Spartan), but also in my own employment activities. Late last year, there was a structural review of our operations at Research Computing Services, as the existing organisational chart was becoming unwieldy and increasingly untenable. I ended up as the team leader for HPC Services and have stepped back somewhat from technical to management of a small but awesome team, along with organisational activities between other service groups (data, cloud) and our very close relationship with the infrastructure group.
Compared to last year, Spartan has increased to 7121 accounts and 2361 projects, mainly in engineering, bioinformatics (especially health) economics, mathematics, and more, and has been cited in at least 55 new papers. Machine learning has been a particularly popular area of interest for several years now on the system, which has especially benefited from Spartan's significant investment in GPUs, whose excellent vector computational performance is evident in the system receiving certification as a global supercomputer in November last year, jumping from a position of 453 (for the GPU partitions alone) in November 2023 to 262 in November 2024. Directly related to Spartan work, I attended two major conferences in person this year, "Supercomputing Asia" and "eResearch Australasia". For the former, I gave a presentation on the International HPC Certification Forum and a poster on usage outcomes from training. For the latter, I gave a presentation on the development of Spartan from a small but innovative system to its current supercomputer status.
Training various postgraduate and postdoctoral researchers on how to use the system has been part of my work for more than a decade now, and it took some acceptance on my part several years ago when I realised that I was the most prolific supercomputer educator in the country. This year, several hundred researchers attended the twenty-two workshops that I conducted on Linux knowledge, regular expressions, HPC job submission, high performance and parallel Python, parallel programming (MPI, OpenMP, CUDA), mathematical and statistical programming (R, Octave/MATLAB, etc.), and more. In addition, each year, I am brought in for lectures and assessments for the University's Cluster and Cloud Computing course, which also has several hundred students. In addition, this year, I took a leave from the University to travel to the Australian Institute for Marine Science in Townsville to run a week-long HPC training course for around fifty of the most switched-on (mostly) young researchers I have ever had the pleasure of meeting.
All of this has resulted in an extremely good review by my manager, who really appreciated the initiatives that I have taken within the new structure. These activities will continue, as I am increasingly emphasising the importance of organisational and technical quality assurance to RCS as a whole. A good portion of next year is already organised: I know I will be attending eResearch New Zealand to deliver a paper on HPC Training for Bioinformatics, eResearch Australasia in Brisbane, and I'll be doing lectures for UniMelb's COMP90024 course. In addition, I'll be doing my best to reduce the number of Spartan workshops I run, in preference to more online videos and documentation (we do a lot of the latter already, but it's never enough to satiate demand).
In many ways, I am deeply blessed to have the sort of job that I do. Even if I get a bit grumpy about bureaucracy at times, I love my work. I get to provide supercomputer support to researchers whose discoveries and inventions make real changes to the world we live in with a stunning return on investment of 7:1 over two years, nearly entirely in the form of positive social externalities. It is computing for medicine, for climatology, for materials, for agriculture, for the environment, rather than computing for social media or games (both of which I use, by the way). It is the sort of computing I was inspired by as a youngster, research-focused and close to the metal. I may add that it is good and secure employment, especially given that technical and knowledge skills are increasingly valuable where the ratio of capital to labour increases. In a nutshell, I am more than happy with how supercomputing is progressing, and I am very happy with this career choice.
I recently replaced the screen of a Google Pixel 3A XL, the new panel is made by tianma and worked well under Andoird, until it doesn’t. On every boot up the screen will work until the phone went to sleep, and then the screen will stop responding to touch, until another reboot. After the screen became unresponsive, the rest of the phone would remain responsive during the locked state and it’s possible to unlock the screen with fingerprint, but there is no way to make the touchscreen responsive again without reboot.
To fix this, go to Settings -> System -> Gestures and disable Double-tap to check phone. After which the screen should no longer stuck into unresponsive state. This seems to be a common problem affecting many phones with replaced screen.
Google will surely shutdown their support forum one day and I encourage everyone to put their notes somewhere reliable, like a selfhosted blog :)
Our 5.94kW solar array with Redflow ZCell battery and Victron Energy inverter/charger system is now slightly over three years old, which means it’s time to review its third year of operation. There are several previous posts in this series:
Go With The Flow (what all the pieces are, what they do, some teething problems)
If you’ve read the above you’ll know that the solar array was originally installed back in 2017 along with a Sanden heat pump hot water service. That initial installation saved us a lot on our electricity bills, but it wasn’t until we got the ZCell and the Victron gear that we were able to really manage our own power. The ZCell allows us to store our own locally generated electricity for later use, and the Victron kit manages everything and gives us a whole lot of fascinating data to look at via the VRM portal.
There were some kinks in the first two years. We missed out on three weeks of prime solar PV generation from January 20 – February 11 in 2022 due to having to replace the MPPT solar charge controller. We also had no solar PV generation from February 17 – March 9 in 2023 on account of having our old tile roof replaced with colorbond steel. In my last post on this topic I wrote:
In both cases our PV generation was lower than it should have been by an estimated 500-600kW. Hopefully nothing like this happens again in future years.
…and then at the very end of that post:
I’m looking forward to doing another one of these posts in a year’s time. Hopefully I will have nothing at all interesting to report.
Alas, something “like this” did happen again, and I have some interesting things to report.
In early December 2023 our battery failed due to a leak in the electrode stack. It was replaced under warranty, but the replacement unit didn’t arrive until March 2024. It was a long three months. Then in August when we were looking at finally purchasing a second ZCell, we discovered that Redflow had made a commercial decision to focus exclusively on large-scale deployments (minimum 200 kWh, i.e. 20 batteries) and was thus no longer selling individual ZBMs for residential or small business use. As an existing customer we probably would have still been able to get a second battery, except that in late August the company went into voluntary administration after failing to secure funding to build a new factory in Queensland. The administrators attempted to seek a sale and/or recapitalisation, but this was ultimately unsuccessful. The company ceased operations on October 18 and subsequently went into liquidation. This raises several questions about the future of our system, but more on that later. First, let’s look at how the system performed in year three.
Here are the figures for grid power in, solar generation, power used by our loads, and power exported to the grid over the past three years. As in the last two posts, the “what?” column here is the difference between grid in plus solar in, minus loads minus export, i.e. the power consumed by the system itself, or the energy cost of the system.
Year
Grid In
Solar In
Total In
Loads
Export
Total Out
what?
2021-2022
8,531
5,640
14,171
10,849
754
11,603
2,568
2022-2023
8,936
5,744
14,680
11,534
799
12,333
2,347
2023-2024
8,878
5,621
14,499
11,162
1,489
12,651
1,848
Note that in year three our grid power usage and solar generation are slightly down from the previous year (-58kWh and -123kWh respectively), so the total power going into the system is lower by 181kWh. Our loads are happily down by 372kWh, a good chunk of which will be due to replacing some old always-on computer equipment with something a bit less power hungry.
What’s really interesting here is that our power exported to the grid is close to double the previous two years, and the energy cost of the system is noticeably lower. In the first two years of operation the latter figure was 16-18% of the total power going into the system, but in year three it’s down to a bit under 13%.
The additional solar export appears to be largely due to the failed battery. Compare the following two graphs from 2022-2023 and 2023-2024.Yellow is direct usage of solar power, blue is solar to battery and red is solar to grid. As you can see there’s way more solar to grid in the period December 2023 – March 2024 when the battery was dead and thus unable to be charged:
Why is there still any blue in that period indicating solar power was going to the battery? This is where things get a bit weird. One consideration is that the battery is presumably still drawing a tiny bit of power for its control circuitry and fans, but when I look at the figures for January 2024 (for example), it shows 76.8 kWh of power going to the battery from solar. There is no way that actually happened with the battery dead and unable to be charged.
Here’s what I think is going on: when the battery went into failure mode, the ZCell Battery Management System (BMS) will have told the Victron gear not to charge it. This effectively disabled the MPPT solar charger, which meant we weren’t able to use our solar at all, not even to run the house. I asked Murray from Lifestyle Electrical Services if there was some way we could reconfigure things to still use solar power with the battery out of action and he remoted in and tweaked some settings. Unfortunately I don’t have an exact record of what was changed at this point, because it was discussed via phone. All I have in my notes is a very terse “Set CGX to use Victron BMS?” which doesn’t make much sense because we don’t have a Victron BMS. Possibly it refers to switching the battery monitor setting from “ZCell BMS” to “MultiPlus-II 48/5000/ 70-50 on VE.Bus”. Anyway, whatever the case, I think we have to assume that the “to battery” and “from battery” figures from December 2023 – March 2024 are all lies.
At this point we were able to limp along with our solar generation still working during the day, but something was still not quite right. Every morning and evening the MPPT appeared to be fighting to run. Watching the console at, say, 08:00, I’d see the MPPT providing solar power for a few seconds, then it’d stop for a second or two, then it’d run again for a few seconds. After some time it would start behaving normally and we’d have solar generation for the day, but then in the evening it would go back to that flicking on and off behaviour. My assumption is that the ZCell BMS was still trying to force the MPPT off. Then in mid-Februrary I suddenly got a whole lot of Battery Low Voltage warnings from the MPPT, which I guess makes sense – the ZCell was still connected and its reported voltage had been very slowly dropping away over the past couple of months. The warnings appeared when it finally hit 2.5V. Murray and I experimented further to try to get the MPPT to stop doing the weird fighting thing, but were unsuccessful. At one point during this we ended up with the Mutli-Plus II inverter/chargers in some sort of fault state and contacted Simon Hackett for further assistance. We got all the Victron gear back into a sensible state and Simon and I spent a bunch of time on a Saturday afternoon messing with everything we could think of, but ultimately we were unable to get the MPPT to provide power from the solar panels, and use grid power, without the battery present. One or the other – grid power only or solar power only – we could do, but we couldn’t get the system to do both at the same time again without the battery present. Turns out a thing that’s designed to be an Energy Storage System just won’t quite work right without the Storage part. So from February 15 through to March 14 when the replacement battery arrived we were running on grid power only with no solar generation.
Happily, we didn’t have any grid power outages during the three months we were without a battery. Our first outage of any note wasn’t until March 23, slightly over a week after the replacement battery was installed. There were a few brief grid outages at other times later – a couple of minutes one day in April, some glitches on a couple of days in August, but the really bad one was on the 1st of September when the entire state got absolutely hammered by extremely severe weather. Given there was a severe weather warning from the BOM I’d made sure the battery was full in advance, which was good because our grid power went out while we were asleep at about 00:37 and didn’t come back on until 17:28. We woke up some time after the grid went down with the battery at 86% state of charge and went around the house to turn off everything we could except for the fridge and freezer, which got our load down to something like 250W. By morning, the battery still had about 70% in it and even though the weather was bad we still had some solar generation, so between battery and solar we got through just fine until the grid came back on in the afternoon. We were lucky though – some folks in the north of the state were without power for two weeks due to this event. I later received a cheque for $160 from TasNetworks in compensation for our outage. I dread to think what the entire event cost everyone, and I don’t just mean in terms of money.
Speaking of money though, the other set of numbers we need to look at are our power bills. Here’s everything from the last seven years:
Year
From Grid
Total Bill
Grid $/kWh
Loads
Loads $/kWh
2016-2017
17,026
$4,485.45
$0.26
17,026
$0.26
2018-2019
9,031
$2,278.33
$0.25
11,827
$0.19
2019-2020
9,324
$2,384.79
$0.26
12,255
$0.19
2020-2021
7,582
$1,921.77
$0.25
10,358
$0.19
2021-2022
8,531
$1,731.40
$0.20
10,849
$0.16
2022-2023
8,936
$1,989.12
$0.22
11,534
$0.17
2023-2024
8,878
$2,108.77
$0.24
11,162
$0.19
As explained in the last post, I’m deliberately smooshing a bunch of numbers together (peak power charge, off peak power charge, feed in tariff, daily supply charge) to arrive at an effective cost/kWh of grid power, then bearing in mind our loads are partially powered from solar I can also determine what it costs us to run all our loads. 2016-2017 is before we got the solar panels and the new hot water service, so you can see the immediate savings there, then further savings after the battery went in in 2021. This year our cost/kWh (and thus our power bill) is higher than last year for two reasons:
We have somehow used more power at peak times than during off-peak times this year compared to last year.
Power prices went up about 8% in July 2023. They actually came down about 1% in July 2024, but most of our year is before that.
I should probably also mention that we actually spent $1,778.94 on power this year, not $2,108.77. That’s thanks largely due to a $250 ‘Supercharged’ Renewable Energy Dividend payment from the Tasmanian Government and $75 from the Federal Government’s Energy Bill Relief Fund. The remaining $4.83 in savings is from Aurora Energy’s ridiculous Power Hours events. I say “ridiculous” because they periodically give you a bunch of time slots to choose from, and once you’ve locked one of them in, any power you use at that time is free. To my mind this incentivises additional power usage, when we should really be doing the exact opposite and trying to use less power over all. So I haven’t tried to use more energy, I’ve just tried to lock in times that were in the evening when we were going to be using more grid power than during the day to scrape in what savings I could.
One other weird thing happened this year with the new battery. ZCells need to go into a maintenance cycle every three days. This happens automatically, but is something I habitually keep an eye on. On September 11 I noticed that we had been four days without running maintenance. Upon investigation of the battery logs I discovered that the Time Since Strip counter and Strip Pump Run Timer were running at half speed, i.e. every minute they were each only advancing by approximately 30 seconds:
I manually put the battery into maintenance mode and Simon was able to remotely reset the CPU by writing some magic number to a modbus register, which got the counters back to the correct speed. I have no idea whether this is a software bug or a hardware issue, but I’ll continue to keep an eye on it. The difficulty is going to be dealing with the problem should it recur, given the demise of Redflow. Simon certainly won’t be able to log in remotely now that the Redflow cloud is down, although there is a manual reset procedure. If you remove the case from the battery there is apparently a small phillips head screw on the panel with the indicator lights. Give the screw a twist and the lights go out. Untwist and the lights come back on and the unit is reset. I have yet to actually try this.
The big question now is, where do we go from here? The Victron gear – the Cerbo GX console, the Multi-Plus II inverter/chargers, the MPPT – all work well with multiple different types of battery, so our basic infrastructure is future-proof. Immediately I hope to be able to keep our ZCell running for as long as possible, and if I’m able to get a second one as a result of the Redflow liquidation I will, simply so that we can ensure the greatest possible longevity of the system before we need to migrate to something else. We will also have to somehow figure out how to obtain carbon socks which need annual replacement to maintain the electrolyte pH. If we had to migrate to something else in a hurry Pylontech might be a good choice, but the problem is that we really don’t want a rack of lithium batteries in the crawl space under our dining room because of the fire risk. There are other types of flow battery out there (vanadium comes to mind) but everything I’ve looked at on that front is either way too big and expensive for residential usage, or is “coming soon now please invest in us it’s going to be awesome”.
I have no idea what year four will look like, but I expect it to be interesting.
As per previous conferences, eResearch Australasia 2024 in Melbourne had several hundred attendees from the scientific research community, research computing developers and operators, administrators and managers, and various vendors. The program gives a very good indication of the level of this conference and the reason that it has been such a success over the last fifteen years and more.
For the first time in the post-COVID environment, the conference was a face-to-face event and a very welcome opportunity to network with old colleagues in this environment as well as the opportunity to discover new people and new developments (as well as hearing some salacious gossip of changes in the eResearch landscape). Various presentations on artificial intelligence and machine learning (away from the current hype over Large Language Models) was prevalent, especially with regard to astounding developments in bioinformatics, of which the developers of Alphafold, the AI program that predicts protein structures, won the Nobel Prize in Chemistry is a prominent example.
My own presentation was on the development of the Spartan general-purpose high performance computing system at the University of Melbourne, which started as a small-scale and very experimental system operating on a shoestring budget, to one of the top systems in the world. I'm pleased to say that the talk seemed to be very well received to the crowded room (my head count was at least 70) and with a number of people asking for the slide deck afterwards; based on the comments from others, Spartan is extremely well regarded within the Australian eResearch community for these successes and for our extensive training program.
I believe buying a Kindle in 2024 is a bad idea, even if you only intend to use it for reading DRM-free locally stored ebooks. Basic functions such as organizing books into folders/collections are locked until the device is registered and with each system update the interface has became slower and more bloated.
Initially I purchased this device because Amazon book store isn’t too bad and it’s one of the easier way to buy Japanese books outside of Japan, but with all the anti-features Amazon add in I don’t think it’s still worth using.
Using a recent exploit and with this downgrader thread on the mobileread forum, I’m able to downgrade my paperwhite to an older 5.11.2 firmware which has a simpler interface while being much more responsive. If you already have a Kindle perhaps this is worth doing.
It’s possible to install alternative UI and custom OS to many Kindle models but they generally run slower than the default launcher. On the open hardware side Pine64 is making an e-ink tablet called the PineNote with an Rockchip RK3566 and 4G of RAM it should be fast enough to handle most documents/ebooks, but currently there is no usable Linux distribution for it.
I acquired a PCW9512 motherboard a year or so ago and I really wanted to get it up and going so I can build a little case for it and turn it into a proper CP/M plus hack machine.
The challenge? Getting a Gotek working on the PCW9512. There are some .. issues.
Specifically - the flash floppy support needs some extra options and board modifications to support the drive detection that the PCW boot block / CP/M loader wants.
The PCW8256/PCW8512 and earlier CP/M versions only support booting from the 180k single side 3" drive. However the later models have a different floppy drive controller and support booting from the 3" 180k drives or 3.5" 720k double sided drive. So, it does some drive detection based on drive behaviour to guess what's going on. For more information take a read of https://www.seasip.info/Unix/Joyce/hardware.pdf.
So here's the jumper config on my little sordan.ie floppy pinout conversion board. Note that Drive 0 -> A: is set, and the Side jumper is set to the top. I haven't got a B: drive jumper set.
And then the jumpers on the Gotek - only the M0 jumper.
I then needed a 720k DSK image of the PCW9512 compatible CP/M. I finally found one - I'll go set up some links on my website to the relevant images soon - and then plugged it in. The system seemed to boot fine - the tracks seeked like it was booting.
But, I couldn't see anything! So, off to build a video buffer and keyboard attachment. Luckily I have a full PCW8256 setup, a spare PCW8512 keyboard and a PCW9512+ keyboard.
It's just some buffer gates and a pull-up / pull-down resistor on the SYNC input from the mainboard so you can select PAL and NTSC at boot. (Yes, I did test it. It does actually select PAL or NTSC.)
Yes, you need a pull up / pull-down resistor.
Then I built my own MVP version - starting with the schematic and some wiring notes.
And then the veroboard prototype!
.. it wouldn't be complete without a picture of the bottom side wiring.
I later added a keyboard adapter - another 4 pin connector next to the keyboard connector (at the top of that image, with the red/black/grey/purple wiring) to a 4 pin DIN socket. Nothing fancy.
Anyway, that's enough to get it to boot and work, as seen here.
This isn't the prettiest PCW9512 setup, but it's mine, and it takes much less space - and much less power - than the rest of the full PCWs I have here. Although I must point out that the monochrome white and monochrome green screens are quite lovely to use.
In any case - it works fine, and I'm completely happy with it. Now I need to build a little plastic box to put it all in, add a DC converter so I can feed it "stuff" and have a nice regulated 5v supply, and then start on the IDE interface.
In my previous post I yanked enough of the PCW9512+ apart and debugged why the power supply just plainly wasn't working.
Now it's time to see if the rest of the board was working.
The first thing to do is test the power supply without having the 9512+ logic board (and the CRT side) powered up. The switch mode supply may not be happy with a load, so an initial failure isn't necessarily fatal.
So it mostly looked like this whilst I was testing it - with that EHT anode cap moved out of the way (just in case - it shouldn't have been powered!)
And honestly? The power supply just worked fine. The caps I tested were fine. All the rails tested fine. I'd have to test them under load to calibrate them, but before doing that I should verify that the 9512+ board and CRT hardware works fine.
So after a bunch of cleaning up, it was ready to put aside and test the mainboard. Testing the mainboard only required 5v - 12v is required for the earlier 3" drives but this drive doesn't require it, and the 28v rail is only used for the 9512+ daisywheel printer. I needed neither, so I just hooked up the 5v rail for testing.
.. and again, the mainboard tested fine. Here it is with the disassembled floppy drive for testing.
The board initialised and showed video/sync on the output side. Ok, great. It needed 800mA at 5v to power up, and it would peak above 1A to load from floppy disk. So pay attention to your power supply!
Next up the floppy drive. It had something in it.
I don't know how or why a sunglasses lens showed up in here, but ... well now I am its proud owner. So I removed that and plugged it all back in.
The motherboard and drive worked enough to fail booting a non-boot disk - and beeped loudly whilst doing so. That tells me the hardware is starting up fine and running the boot ROM code, but it's not reading from the drive.
And well, the drive was dead. The floppy drive rubber band was toast.
.. I could figure out the belt width (~2mm) and thickness but I couldn't figure out the size. The drive is a Citizen UODC-45A and I couldn't find any service manual / documentation on this drive at all.
But luckily someone had! And the belt he ordered from DataServe Retro is for a cassette deck - flat, 71mm diameter, 2.8mm wide, 0.6mm thick! And to make life easier, here's the link to the belt in question.
I recommend watching the video to get an idea of how to get the belt correctly around the capstan to line up the belt between the small motor and the large drive shaft. It's quite a squeeze.
First up was cleaning up the old bits.
First, the motor spindle.
Finding all the fun bits of the belt stuck in the drive - I had to shake it multiple times to get it all out.
And here's some on the drive spindle itself. In fact, after doing all of this I found more stuck UNDER the spindle which kept the drive from reliably spinning at the right RPM, resulting in loads failing! (Phew, I wasn't looking forward to having to calibrate it.)
In any case, once I had assembled the unit and stuck in a disk, it made the right kinds of seeking noises and .. well, I guess it had booted.
And .. well, it started booting fine. But the keyboard didn't work, and the display was way too bright and over-sized. Let's tackle the keyboard... oh it's just cracked solder joints. Easy.
And now the picture!
Now the important part - this is now under load, so I need to double and triple check the power supply calibration. If it's getting > 12v then this'll happen. So before you go and try re-calibrate your monitor, check the power rails.
And yup - it was dumping 14.5v into the monitor B+ rail. Things look MUCH better after calibrating this back to 12v.
No obvious calibration needed!
And finally, running a basic RAM test.
So, it boots fine, RAM tests fine, copies disks fine. I haven't yet dumped CP/M software on here to use - I think I'll make up a disk full of CP/M games.
The next post will cover MAKING a 720k CP/M boot disk for this thing - more of a pain in the rear than I'd like, even with a suitable MS-DOS 80386 IBM PC clone available.
I'm on a bit of a "i wish I had a PCW as a kid" kick. So yeah, I have a working out of the box PCW8256 that has been upgraded to a PCW8512 (but with only one floppy drive for now. Stay tuned.) I got lucky; that one was in the US and didn't need any modification to work here. (And, amusingly, although it's setup for US power - and shipped with locAscript instead of locOscript, it's still configured for 50Hz UK and 256 line display!)
But yes, finding PCW's in the US - well, any Amstrad really - is super difficult. So when I saw a PCW9512+ for sale by someone in Florida, I jumped at it.
... unfortunately although the seller was listed in Florida, it came from Cairo! So would it survive the trip? who knows. It was sold as "didn't power on", the internal photos didn't show any evidence that the tube was cracked, so .. maybe I'd get lucky.
Coming from Cairo meant that it would be wired for 240v power, and indeed it was. So, up on the bench it went. And yes, it was very dead. So, I pulled out the boards and started testing the switch mode power supply.
First - start by discharging all the AC side capacitors and EHT side capacitors - and the tube, just in case! - and then start checking components from the AC line input all the way to the big switching coil. If you're lucky, it'll be something stupid like the fuse. If you're unlucky, the coil is open or the switching transistor is dead. (Or in the case of the PCW, a big honking integrated switchmode controller hybrid IC which is unobtanium in 2024.)
Here's what I started on:
This covers the AC input, EMI filtering, switching and AC -> DC rectification. The output of that rectification from 240v AC RMS is around 330v DC peak. So be careful, that stuff will definitely kill you dead!
Basic continuity tests of each of those components in circuit didn't show anything obviously wrong. But since there's a rectifier there, it's not always obvious that something's bad. So it's best to lift the parts out to test. So I did that, and .. oh look. R5001 is very, very dead.
I spoke with Jaz (https://mstdn.social/@coregaze) about it a bit to figure out why it's there. They pointed out it's very likely a damper resistor to stop any ringing that may happen between the filter coil on the left side, the capacitors in the circuit around it and the diodes switching on and off. It likely would get hot in normal use, so the fun question was - did it die because the whole unit was just running for too long in a hot room, or is something else dead / shorted and the power supply was being over-taxed?
In any case I wanted to test the rest of the power supply with that fixed, but I didn't (yet) want to light up the monitor circuitry. If there's a problem with the monitor circuitry - eg a shorted power transistor or hybrid IC - I didn't want to risk further power supply damage. So, back to the circuit diagram I go to see how the monitor side is powered up.
On the power supply side, there is a separate 12v DC supply to the monitor, called B+:
And on the monitor side, there's a few places it branches off of that B+ net:
Ok, so off to the layout diagram!
Now, see the track there with W2? That goes off to the horizontal deflection circuitry and flyback input to feed the tube EHT. The rest of that W2 track/net is all of the other monitor circuitry. So how's it hook up into the Q5003/VR5002/C5026 net? The actual 12v monitor B+ line?
The answer - a solder blob! Here's how it looks after I was Very Intentional about cleaning around it after desoldering it.
So, with that blob removed, the 12v B+ output from the power supply doesn't feed the B+ input into the monitor, so none of the CRT related hardware is energised!
Well then! Off to test the rest of the power supply circuitry I go!
I’ve been daily driving the PinePhone Pro with swmo for some times now, it’s not perfect but I still find it be one of the most enjoyable devices I’ve used. Probably only behind BlackBerry Q30/Passport which also has a decent keyboard and runs an unfortunately locked-down version of QNX. For me it’s less like a phone and more like a portable terminal for times when using a full size laptop is uncomfortable or impractical, and with the keyboard it’s possible to write lengthy articles on the go.
This isn’t the only portable Linux terminal I owned, before this I used a Nokia N900 which till this day is still being maintained by the maemo leste team, but the shutdown of 3G network in where I live made it significantly less usable as a phone and since it doesn’t have a proper USB port I cannot use it as a serial console easily.
The overall experience on the PPP now as of 2024 isn’t as polished as that of the BlackBerry Passport, and adhoc hacks are often required to get the system going, however as the ecosystem progress the experience will also improve with new revisions of hardware and better software.
I use sxmo and swmo interchangeably in this post, they refer to the same framework running under Xorg and wayland, the experience is pretty much the same.
The default scaling of sxmo doesn’t allow the many desktop applications to display their window properly, especially when such application is written under the assumption of being used on a larger screen. To set the scaling to something more reasonable, add the following line to ~/.config/sxmo/sway:
exec wlr-randr --output DSI-1 --scale 1.3
When using swmo environment initialization is mostly done in ~/.config/sxmo/sway and ~/.config/sxmo/xinit is not used.
Scaling for Firefox needs to be adjusted separately by first enabling compact UI and then set settings -> default zoom to your liking.
I used lightdm as my session manager, to launch lightdm in landscape mode, change the display-setup-script line in the [Seat:*] section of /etc/lightdm/lightdm.conf to:
To rotate Linux framebuffer, add fbcon=rotate:1 to the U_BOOT_PARAMETERS line in /usr/share/u-boot-menu/conf.d/mobian.conf and run u-boot-update to apply.
I also removed quiet splash from U_BOOT_PARAMETERS to disable polymouth animation as it isn’t very useful on landscape mode.
Swmo doesn’t come with a secure screen locker. but swaylock works fine and it can be bind to a key combination with sway’s configure file. To save some battery life, systemctl suspend can be triggered after swaylock, to bind that to Meta+L:
The default keymap for the PinePhone keyboard is missing a few useful keys, namely F11/F12 and PgUp/PgDown. To create those keys I used evremap(1) to make a custom keymap. Unfortunately the Fn key cannot be mapped as a layer switcher easily, so I opted to remap AltG and Esc as my primary modifiers.
I’m working on a Debian package for evremap and it will be made available for Debian/Mobian soon.
Incus is a container/VM manager for Linux, it’s available for Debian from bookworm/backports and is a fork of LXD by the original maintainers behind LXD. It works well for creating isolated and unprivileged containers. I have multiple incus containers on the PinePhone Pro for Debian packaging and it’s a better experience than manually creating and managing chroots. In case there is a need for running another container inside an unprivileged incus container, it’s possible to configure incus to intercept certain safe system calls and forward them to the host, removing the need for using privileged container.
Sway is decently usable in convergence mode, in which the phone is connected to a dock that outputs to an external display and keyboard and mouse are used as primary controls instead of the touchscreen.
This isn’t surprising since sway always had great support for multi monitor, however another often overlooked convergence mode is with waypipe. In this mode another Linux machine (e.g. a laptop) can be used to interact with applications running on the phone and the phone will be kept charged by the laptop. This is particularly useful for debugging phone applications or for accessing resources on the phone (e.g. sending and receiving sms). One thing missing in this setup is that graphic applications cannot roam between the phone and the external system (e.g. move running applications from one machine to another). Xpra does this for Xorg but doesn’t work with wayland.
Due to the simplicity of the swmo environment it’s not too difficult to get the system running with SELinux in Enforcing mode, and I encourage everyone reading this to try it. If running debian/mobian a good starting point is the SELinux/Setup page on Debian wiki.
Note: selinux-activate won’t add the required security=selinux kernel option to u-boot (it only deals with GRUB) so you have to manually add it to the U_BOOT_PARAMETERS line in /usr/share/u-boot-menu/conf.d/mobian.conf and run u-boot-update after selinux-activate. The file labeling process can easily take 10 minutes and the progress won’t be displayed on the framebuffer (only visible via the serial console).
SELinux along with the reference policy aren’t enough for building a reasonably secure interactive system, but let’s leave that for a future post.
The April 2024 meeting is the first meeting after Everything Open 2024 and the discussions are primarily around talks and lectures people found interesting during the conference, including the n3n VPN and the challenges of running personal email server. At the start of the meeting Yifei Zhan demonstrated a development build of Maemo Leste, an active Maemo-like operating system running on a PinePhone Pro.
Other topics discussed including modern network protocol ossification, SIP and possible free and open source VoLTE implementation.
I bought a "dead" 1551 drive a few months ago. It's a european model, only 220v, and they said "it smoked when it was on". Well, i figured it was dead but I figured maybe not dead dead.
So, step one was removing the .. huge ass transformer.
I stripped off the regulators and hooked it up to a pair of bench supplies to feed 5v and 12v with a current limit.
(And yes, by this stage I had done a bunch of debugging already, so i had taken out the ROM, PLA and RAM and socketed the PLA / RAM.)
I unplugged the drive head cable and measured it - the heads measured just fine. So, I left them off whilst I debugged everything else.
Then I fired it up - the drive spun, a bunch of CPU pins were blinking on the oscilloscope, but nothing quite worked. The drive constantly spinning is a sign that even the early boot code isn't running.
So I then wanted to know if the CPU worked. The problem? All the pins kinda looked fine. Except A15.
It looked very sus. Like ok, NMOS has some fun rise times, but the other pins weren't this fun.
I decided to socket everything so I could pull the RAM and address decode gate array out. I thought about the 42 pin drive gate array IC but I figured if that was fried I was in for an unfun time.
The next thing was to figure out how to test that the CPU kinda worked. I figured I could write a little program to toggle the activity LED quickly and see it on my scope. I started with the disassembly here - http://www.cbmhardware.de/show.php?r=7&id=21 - to see how the LED is blinked. The 6510T CPU has an 8 bit IO port (versus the 6 bit IO port on the 6510 CPU).
The program looked roughly like this:
.org $ff00 SEI ; disable interrupts CLD ; clear flags LDA #$6F ; IO direction bits STA $00 ; program IO direction bits loop: LDA #$60 ; turn on LED STA $01 ; program IO port LDA #$68 ; turn off LED STA $01 ; program IO port JMP loop
.org $fffa .byte $00, $ff, $00, $ff, $00, $ff
This didn't work. So, I got a new CPU. A15 on that CPU was much better.
Then this did work. The LED was blinking at a few hundred kilohertz. Ok, but the original ROM? Nothing. My guess is the ROM is also busted, so I programmed another 27128 EPROM with the right image and inserted it into the drive.
Everything worked! So, time to plug in the head cable OH CRAP I PLUGGED IT IN BACKWARDS. Bang, I blew the head coils. Crap.
Anyway, the rest of the drive seemed fine. Stepper motor, drive motor control. Now, the challenge - it's a mitsumi drive. I went on ebay to find a replacement drive - lots of "untested" 1541's everywhere. But I did find a "tested, guaranteed works" SX-64 drive. However, it's an Alps drive. They're supposed to be more reliable, but .. well, it arrived a few days later.
The main physical difference between the two is the connector. The thing I remember is that the write current is slightly different and some 1541 drives have a jumper to change said current.
Luckily there's a 1541 service manual and it has the Alps drive pinout for the 1541, which is surprisingly exactly what I need for the 1551:
So I followed this guide, verified at each step that it worked, and connected it all up.
And yes, I put superglue in the key hole for the head connector so I didn't plug it in backwards.
And .. well, it works!
Well, kinda. I had the commodore 16 drop into the monitor after HEADER (which formats a blank disk) completed. I've also had some issues with commands hanging and not running on the drive. So, there may be some other issues lurking.
I also want to figure out a suitable mod for the write head current change.
But hey, I guess I do have a working Alps drive in my 1551.
And yes I did tear the head apart to see how it's put together... :-)
The PinePhone keyboard contains a battery, which will be used to charge the PinePhone when the keyboard is attached. Althrough there are existing warnings on the pine64 wiki which sums up to ‘don’t charge or connect anything to your pinephone’s type C interface when the keyboard is attached’, my two pinephone keyboards still managed to fry themselves, with one releasing stinky magic smoke and the other melting the plastic around the pogo pins on the pinephone backplate.
This all happened while the pinephone’s type C interface being physically block when attached to the keyboard. In the first case, the keyboard’s controller PCB blew up when I tried to charge it, in the latter case the keyboard somehow overheated and melted the plastic near the pogo interface on the phone side.
Pine64 provided me a free replacement keyboard after multiple emails back and forth, but according to Pine64 there will be no more free replacement for me in future, and there is no guarantee that this will not happen to my replacement keyboard.
The cost for replacing all the fried parts with spare parts from the Pine64 store is about 40 USD (pogo pins + backplate + keyboard PCB), and considering this problem is likely to happen again, I don’t think purchasing those parts is a wise decision.
Both the melting plastic and the magic smoke originated from the fact that charges are constantly shuffled around when the keyboard is attached to the pinephone, and since the keyboard can function independently from the battery, we can disconnect and remove the battery from the keyboard case to make sure it will not blow up again. After such precedure the keyboard will keep functioning althrough the keyboard-attached pinephone might flip over much more easily due to the lightened keyboard base. Be aware that the keyboard isn’t designed to be taken apart, and doing so will likely result in scratches on the case. As for me, I’d much rather have a keyboard case without builtin battery than have something that can overheat or blow up.
On Friday, 1st March, it will be exactly one year since I walked into
Zen Motorcycles, signed the
paperwork, and got on my brand new Energica Experia electric motorbike. I
then rode it back to Canberra, stopping at two places to charge along the
way, but that was more in the nature of making sure - it could have done the
trip on one better-chosen charging stop.
I got a call yesterday from a guy who had looked at the Experia Bruce has at
Zen and was considering buying one. I talked with him for about three
quarters of an hour, going through my experience, and to sum it up simply I
can just say: this is a fantastic motorbike.
Firstly, it handles exactly like a standard motorbike - it handles almost
exactly like my previous Triumph Tiger Sport 1050. But it is so much easier
to ride. You twist the throttle and you go. You wind it back and you slow
down. If you want to, the bike will happily do nought to 100km/hr in under
four seconds. But it will also happily and smoothly glide along in traffic.
It says "you name the speed, I'm happy to go". It's not temperamental or
impatient; it has no weird points where the throttle suddenly gets an extra
boost or where the engine braking suddenly drops off. It is simple to ride.
As an aside, this makes it perfect for lane filtering. On my previous bike
this would always be tinged with a frisson of danger - I had to rev it and
ease the clutch in with a fair bit of power so I didn't accidentally stall it,
but that always took some time. Now, I simply twist the throttle and I am
ahead of the traffic - no danger of stalling, no delay in the clutch gripping,
just power. It is much safer in that scenario.
I haven't done a lot of touring yet, but I've ridden up to Gosford once and
up to Sydney several times. This is where Energica really is ahead of pretty
much every other electric motorbike on the market now - they do DC fast
charging. And by 'fast charger' here I mean anything from 50KW up; the
Energica can only take 25KW maximum anyway :-) But this basically means I
have to structure any stops we do around where I can charge up - no more
stopping in at the local pub or a cafe on a whim for morning tea. That has
to either offer DC fast charging or I'm moving on - the 3KW onboard AC
charger means a 22KW AC charger is useless to me. In the hour or two we
might stop for lunch I'd only get another 60 - 80 kilometres more range on
AC; on DC I would be done in less than an hour.
But OTOH my experience so far is that structuring those breaks around where I
can charge up is relatively easy. Most riders will furiously nod when I say
that I can't sit in the seat for more than two hours before I really need to
stretch the legs and massage the bum :-) So if that break is at a DC charger,
no problems. I can stop at Sutton Forest or Pheasant's Nest or even
Campbelltown and, in the time it takes for me to go to the toilet and have a
bit of a coffee and snack break, the bike is basically charged and ready to
go again.
The lesson I've learned, though, is to always give it that bit longer and
charge as much as I can up to 80%. It's tempting sometimes when I'm standing
around in a car park watching the bike charge to move on and charge up a bit
more at the next stop. The problem is that, with chargers still relatively
rare and there often only being one or two at each site, a single charger
not working can mean another fifty or even a hundred kilometres more riding.
That's a quarter to half my range, so I cannot afford to risk that. Charge
up and take a good book (and a spare set of headphones).
In the future, of course, when there's a bank of a dozen DC fast chargers in
every town, this won't be a problem. Charger anxiety only exists because
they are still relatively rare. When charging is easy to find and always
available, and there are electric forecourts like the UK is starting to get,
charging stops will be easy and will fit in with my riding.
Anyway.
Other advantages of the Experia:
You can get it with a complete set of Givi MonoKey top box and panniers. This
means you can buy your own much nicer and more streamlined top box and it fits
right on.
Charging at home takes about six hours, so it's easy to do overnight. The
Experia comes with an EVSE so you don't need any special charger at home. And
really, since the onboard AC charger can only accept 3KW, there's hardly any
point in spending much money on a home charger for the Experia.
Minor niggles:
The seat is a bit hard. I'm considering getting the
EONE
Canyon saddle, although I also just need to try to work out how to get
underneath the seat to see if I can fit my existing sheepskin seat cover.
There are a few occasional glitches in the display in certain rare situations.
I've mentioned them to Energica, hopefully they'll be addressed.
Way back in the distant past, when the Apple ][ and the Commodore 64 were king, you could read the manual for a microprocessor and see how many CPU cycles each instruction took, and then do the math as to how long a sequence of instructions would take to execute. This cycle counting was used pretty effectively to do really neat things such as how you’d get anything on the screen from an Atari 2600. Modern CPUs are… complex. They can do several things at once, in a different order than what you wrote them in, and have an interesting arrangement of shared resources to allocate.
So, unlike with simpler hardware, if you have a sequence of instructions for a modern processor, it’s going to be pretty hard to work out how many cycles that could take by hand, and it’s going to differ for each micro-architecture available for the instruction set.
When designing a microprocessor, simulating what a series of existing instructions will take to execute compared to the previous generation of microprocessor is pretty important. The aim should be for it to take less time or energy or some other metric that means your new processor is better than the old one. It can be okay if processor generation to generation some sequence of instructions take more cycles, if your cycles are more frequent, or power efficient, or other positive metric you’re designing for.
Programmers may want this simulation too, as some code paths get rather performance critical for certain applications. Open Source tools for this aren’t as prolific as I’d like, but there is llvm-mca which I (relatively) recently learned about.
llvm-mca is a performance analysis tool that uses information available in LLVM (e.g. scheduling models) to statically measure the performance of machine code in a specific CPU.
So, when looking at an issue in the IPv6 address and connection hashing code in Linux last year, and being quite conscious of modern systems dealing with a LOT of network packets, and thus this can be quite CPU usage sensitive, I wanted to make sure that my suggested changes weren’t going to have a large impact on performance – across the variety of CPU generations in use.
There’s two ways to do this: run everything, throw a lot of packets at something, and measure it. That can be a long dev cycle, and sometimes just annoying to get going. It can be a lot quicker to simulate the small section of code in question and do some analysis of it before going through the trouble of spinning up multiple test environments to prove it in the real world.
So, enter llvm-mca and the ability to try and quickly evaluate possible changes before testing them. Seeing as the code in question was nicely self contained, I could easily get this to a point where I could easily get gcc (or llvm) to spit out assembler for it separately from the kernel tree. My preference was for gcc as that’s what most distros end up compiling Linux with, including the Linux distribution that’s my day job (Amazon Linux).
In order to share the results of the experiments as part of the discussion on where the code changes should end up, I published the code and results in a github project as things got way too large to throw on a mailing list post and retain sanity.
I used a container so that I could easily run it in a repeatable isolated environment, as well as have others reproduce my results if needed. Different compiler versions and optimization levels will very much produce different sequences of instructions, and thus possibly quite different results. This delta in compiler optimization levels is partially why the numbers don’t quite match on some of the mailing list messages, although the delta of the various options was all the same. The other reason is learning how to better use llvm-mca to isolate down the exact sequence of instructions I was caring about (and not including things like the guesswork that llvm-mca has to do for branches).
One thing I learned along the way is how to better use llvm-mca to get the results that I was looking for. One trick is to very much avoid branches, as that’s going to be near complete guesswork as there’s not a simulation of the branch predictor (at least in the version I was using.
The big thing I wanted to prove: is doing the extra work having a small or large impact on number of elapsed cycles. The answer was that doing a bunch of extra “work” was essentially near free. The CPU core could execute enough things in parallel that the incremental cost of doing extra work just… wasn’t relevant.
This helped getting a patch deployed without impact to performance, as well as get a patch upstream, fixing an issue that was partially fixed 10 years prior, and had existed since day 1 of the Linux IPv6 code.
Naturally, this wasn’t a solo effort, and that’s one of the joys of working with a bunch of smart people – both at the same company I work for, and in the broader open source community. It’s always humbling when you’re looking at code outside your usual area of expertise that was written (and then modified) by Really Smart People, and you’re then trying to fix a problem in it, while trying to learn all the implications of changing that bit of code.
Anyway, check out llvm-mca for your next adventure into premature optimization, as if you’re going to get started with evil, you may as well start with what’s at the root of all of it.
At this rate, there is no real blogging here, regardless of the lofty plans to starting writing more. Stats update from Hello 2023:
219 days on the road (less than 2022! -37, over a month, shocking), 376,961km travelled, 44 cities, 17 countries.
Can’t say why it was less, because it felt like I spent a long time away…
In Kuala Lumpur, I purchased a flat (just in time to see Malaysia go down), and I swapped cars (had a good 15 year run). I co-founded a company, and I think there is a lot more to come.
2024 is shaping up to be exciting, busy, and a year, where one must just do.
It’s time for a review of the second year of operation of our Redflow ZCell battery and Victron Energy inverter/charger system. To understand what follows it will help to read the earlier posts in this series:
Go With The Flow (what all the pieces are, what they do, some teething problems)
TANSTAAFL (review/analysis of the first year of operation)
In case ~12,000 words of background reading seem daunting, I’ll try to summarise the most important details here:
We have a 5.94kW solar array hooked up to a Victron MPPT RS solar charge controller, two Victron 5kW Multi-Plus II inverter/chargers, a Victron Cerbo GX console, and a single 10kWh Redflow ZCell battery. It works really well. We’re using most of our generated power locally, and it’s enabled us to blissfully coast through several grid power outages and various other minor glitches. The Victron gear and the ZCell were installed by Lifestyle Electrical Services.
Redflow batteries are excellent because you can 100% cycle them every day, and they aren’t a giant lump of lithium strapped to your house that’s impossible to put out if it bursts into flames. The catch is that they need to undergo periodic maintenance where they are completely discharged for a few hours at least every three days. If you have more than one, that’s fine because the maintenance cycles interleave (it’s all automatic). If you only have one, you can’t survive grid outages if you’re in a maintenance period, and you can’t ordinarily use the Cerbo’s Minimum State of Charge (MinSoC) setting to perpetually keep a small charge in the battery in case of emergencies. As we still only have one battery, I’ve spent a fair bit of time experimenting to mitigate this as much as I can.
The system itself requires a certain amount of power to run. Think of the pumps and fans in the battery, and the power used directly by the inverters and the console. On top of that a certain amount of power is simply lost to AC/DC conversion and charge/discharge inefficiencies. That’s power that comes into your house from the grid and from the sun that your loads, i.e. the things you care about running, don’t get to use. This is true of all solar PV and battery storage systems to a greater or lesser degree, but it’s not something that people always think about.
With the background out of the way we can get on to the fun stuff, including a roof replacement, an unexpected fault after a power outage followed by some mains switchboard rewiring, a small electrolyte leak, further hackery to keep a bit of charge in the battery most of the time, and finally some numbers.
The big job we did this year was replacing our concrete tile roof with colorbond steel. When we bought the house – which is in a rural area and thus a bushfire risk – we thought: “concrete brick exterior, concrete tile roof – sweet, that’s not flammable”. Unfortunately it turns out that while a tile roof works just fine to keep water out, it won’t keep embers out. There’s a gadzillion little gaps where the tiles overlap each other, and in an ember attack, embers will get up in there and ignite the fantastic amount of dust and other stuff that’s accumulated inside the ceiling over several decades, and then your house will burn down. This could be avoided by installing roof blanket insulation under the tiles, but in order to do that you have to first remove all the tiles and put them down somewhere without breaking them, then later put them all back on again. It’s a lot of work. Alternately, you can just rip them all off and replace the whole lot with nice new steel, with roof blanket insulation underneath.
Of course, you need good weather to replace a roof, and you need to take your solar panels down while it’s happening. This meant we had twenty-two solar panels stacked on our back porch for three weeks of prime PV time from February 17 – March 9, 2023, which I suspect lost us a good 500kW of power generation. Also, the roof job meant we didn’t have the budget to get a second ZCell this year – for the cost of the roof replacement, we could have had three new ZCells installed – but as my wife rightly pointed out, all the battery storage in the world won’t do you any good if your house burns down.
We had at least five grid power outages during the year. A few were brief, the grid being down for only a couple of minutes, but there were two longer ones in September (one for 30 minutes, one for about an hour and half). We got through the long ones just fine with either the sun high in the sky, or charge in the battery, or both. One of the earlier short outages though uncovered a problem. On the morning of May 30, my wife woke up to discover there was no power, and thus no running water. Not a good thing to wake up to. This happened while I was away, because of course something like this would happen while I was away. It turns out there had been a grid outage at about 02:10, then the grid power had come back, but our system had not. The Multis ended up in some sort of fault state and were refusing to power our loads. On the console was an alarm message: “#8 – Ground relay test failed”.
That doesn’t look good.
Note the times in the console messages are about 08:00. I confirmed via the logs from the VRM portal that the grid really did go out some time between 02:10 and 02:15, but after that there was nothing in the logs until 07:59, which is when my wife used the manual changeover switch to shift all our loads back to direct grid power, bypassing the Victron kit. That brought our internet connection back, along with the running water. I contacted Murray Roberts from Lifestyle Electrical and Simon Hackett for assistance, Murray logged in remotely and reset the Multis, my wife flicked the changeover switch back and everything was fine. But the question remained, what had gone wrong?
The ground relay in the Multis is there to connect neutral to ground when the grid fails. Neutral and ground are already physically connected on the grid (AC input) side of the Multis in the main switchboard, but when the grid power goes out, the Multis disconnect their inputs, which means the loads on the AC output side no longer have that fixed connection from neutral to ground. The ground relay activates in this case to provide that connection, which is necessary for correct operation of the safety switches on the power circuits in the house.
The ground relay is tested automatically by the Multis. Looking up Error 8 – Ground relay test failed on Victron’s web site indicated that either the ground relay really was faulty, or possibly there was a wiring fault or an issue with one of the loads in our house. So I did some testing. First, with the battery at 50% State of Charge (SoC), I did the following:
Disconnected all loads (i.e. flipped the breaker on the output side of the Multis)
Killed the mains (i.e. flipped the breaker on the input side of the Multis)
Verified the system switched to inverting mode (i.e. running off the battery)
Restored mains power
Verified there was no error
This demonstrated that the ground relay and the Multis in general were fine. Had there been a problem at that level we would have seen an error when I restored mains power. I then reconnected the loads and repeated steps 2-5 above. Again, there was no error which indicated the problem wasn’t due to a wiring defect or short in any of the power or lighting circuits. I also re-tested with the heater on and the water pump running just in case there may have been an issue specifically with either of those devices. Again, there was no error.
The only difference between my test above and the power outage in the middle of the night was that in the middle of the night there was no charge in the battery (it was right after a maintenance cycle) and no power from the sun. So in the evening I turned off the DC isolators for the PV and deactivated my overnight scheduled grid charge so there’d be no backup power of any form in the morning. Then I repeated the test:
Disconnected all loads
Killed the mains.
Checked the console which showed the system as “off”, as opposed to “inverting”, as there was no battery power or solar generation
Restored mains power
Shortly thereafter, I got the ground relay test failed error
The underlying detailed error message was “PE2 Closed”, which meant that it was seeing the relay as closed when it’s meant to be open. Our best guess is that we’d somehow hit an edge case in the Multi’s ground relay test, where they maybe tried to switch to inverting mode and activated the ground relay, then just died in that state because there was no backup power, and got confused when mains power returned. I got things running again by simply power cycling the Multis.
So it kinda wasn’t a big deal, except that if the grid went out briefly with no backup power, our loads would remain without power until one of us manually reset the system. This was arguably worse than not having the system at all, especially if it happened in the middle of the night, or when we were away from home. The fact that we didn’t hit this problem in the first year of operation is a testament to how unlikely this event is, but the fact that it could happen at all remained a problem.
One fix would have been to get a second battery, because then we’d be able to keep at least a tiny bit of backup power at all times regardless of maintenance cycles, but we’re not there yet. Happily, Simon found another fix, which was to physically connect the neutral together between the AC input and AC output sides of the Multis, then reconfigure them to use the grid code “AS4777.2:2015 AC Neutral Path externally joined”. That physical link means the load (output) side picks up the ground connection from the grid (input) side in the swichboard, and changing the grid code setting in the Multis disables the ground relay and thus the test which isn’t necessary anymore.
Murray needed to come out anyway to replace the carbon sock in the ZCell (a small item of annual maintenance) and was able to do that little bit of rewriting and configuration at the same time. I repeated my tests both with and without backup power and everything worked perfectly, i.e. the system came back immediately by itself after a grid outage with no backup power, and of course switched over to inverting just fine when there was backup power available.
This leads to the next little bit of fun. The carbon sock is a thing that sits inside the zinc electrolyte tank and helps to keep the electrolyte pH in the correct operating range. Unfortunately I didn’t manage to get a photo of one, but they look a bit like door snakes. Replacing the carbon sock means opening the case, popping one side of the Gas Handling Unit (GHU) off the tank, pulling out the old sock and putting in a new one. Here’s a picture of the ZCell with the back of the case off, indicating where the carbon sock goes:
The tank on the left (with the cooling fan) is for zinc electrolyte. The tank on the right is for bromine electrolyte. The blocky assembly of pipes going into both tanks is the GHU. The rectangular box behind that contains the electrode stacks.
When Murray popped the GHU off, he noticed that one of the larger pipes on one side had perished slightly. Thankfully he happened to have a spare GHU with him so was able to replace the assembly immediately. All was well until later that afternoon, when the battery indicated hardware failure due to “Leak 1 Trip” and shut itself down out of an abundance of caution. Upon further investigation the next day, Murry and I discovered there was a tiny split in one of the little hoses going into the GHU which was letting the electrolyte drip out.
Drip… Drip… Drip…
This small electrolyte leak was caught lower down in the battery, where the leak sensor is. Murray sucked the leaked electrolyte out of there, re-terminated that little hose and we were back in business. I was happy to learn that Redflow had obviously thought about the possibility of this type of failure and handled it. As I said to Murray at the time, we’d rather have a battery that leaks then turns itself off than a battery that catches fire!
Aside from those two interesting events, the rest of the year of operation was largely quite boring, which is exactly what one wants from a power system. As before I kept a small overnight scheduled charge and a larger late afternoon scheduled charge active on weekdays to ensure there was some power in the battery to use at peak (i.e. expensive) grid times. In spring and summer the afternoon charge is largely superfluous because the battery has usually been well filled up from the solar by then anyway, but there’s no harm in leaving it turned on. The one hack I did do during the year was to figure out a way to keep a small (I went with 15%) MinSoC in the battery at all times except for maintenance cycle evenings, and the morning after. This is more than enough to smooth out minor grid outages of a few minutes, and given our general load levels should be enough to run the house for more than an hour overnight if necessary, provided the hot water system and heating don’t decide to come on at the same time.
My earlier experiment along these lines involved a script that ran on the Cerbo twice a day to adjust scheduled charge settings in order to keep the battery at 100% SoC at all times except for peak electricity hours and maintenance cycle evenings. As mentioned in TANSTAAFL I ran that for all of July, August and most of September 2022. It worked fine, but ultimately I decided it was largely a waste of energy and money, especially when run during the winter months when there’s not much sun and you end up doing a lot of grid charging. This is a horribly inefficient way of getting power into the battery (AC to DC) versus charging the battery direct from solar PV. We did still use those scripts in the second year, but rather more judiciously, i.e. we kept an eye on the BOM forecasts as we always do, then occasionally activated the 100% charge when we knew severe weather and/or thunderstorms were on the way, those being the things most likely to cause extended grid outages. I also manually triggered maintenance on the battery earlier than strictly necessary several times when we expected severe weather in the coming days, to avoid having a maintenance cycle (and thus empty battery) coincide with potential outages. On most of those occasions this effort proved to be unnecessary. Bearing all that in mind, my general advice to anyone else with a single ZCell system (aside from maybe adding scheduled charges to time-shift expensive peak electricity) is to just leave it alone and let it do its thing. You’ll use most of your locally generated electricity onsite, you’ll save some money on your power bills, and you’ll avoid some, but not all, grid outages. This is a pretty good position to be in.
That said, I couldn’t resist messing around some more, hence my MinSoC experiment. Simon’s installation guide points out that “for correct system operation, the Settings->ESS menu ‘Min SoC’ value must be set to 0% in single-ZCell systems”. The issue here is that if MinSoC is greater than 0%, the Victron gear will try to charge the battery while the battery is simultaneously trying to empty itself during maintenance, which of course just isn’t going to work. My solution to this is the following script, which I run from a cron job on the Cerbo twice a day, once at midnight UTC and again at 06:00 UTC with the --check-maintenance flag set:
Midnight UTC corresponds to the end of our morning peak electricity time, and 06:00 UTC corresponds to the start of our afternoon peak. What this means is that after the morning peak finishes, the MinSoC setting will cause the system to automatically charge the battery to the value specified if it’s not up there already. Given it’s after the morning peak (10:00 AEST / 11:00 AEDT) this charge will likely come from solar PV, not the grid. When the script runs again just before the afternoon peak (16:00 AEST / 17:00 AEDT), MinSoC is set to either the value specified (effectively a no-op), or zero if it’s a maintenance day. This allows the battery to be discharged correctly in the evening on maintenance days, while keeping some charge every other day in case of emergencies. Unlike the script that tries for 100% SoC, this arrangement results in far less grid charging, while still giving protection from minor outages most of the time.
In case Simon is reading this now and is thinking “FFS, I wrote ‘MinSoC must be set to 0% in single-ZCell systems’ for a reason!” I should also add a note of caution. The script above detects ZCell maintenance cycles based solely on the configured maintenance time limit and the duration since last maintenance. It does not – and cannot – take into account occasions when the user manually forces maintenance, or situations in which a ZCell for whatever reason hypothetically decides to go into maintenance of its own accord. The latter shouldn’t generally happen, but it can. The point is, if you’re running this MinSoC script from a cron job, you really do still want to keep an eye on what the battery is doing each day, in case you need to turn that setting off and disable the cron job. If you’re not up for that I will reiterate my general advice from earlier: just leave the system alone – let it do its thing and you’ll (almost always) be perfectly fine. Or, get a second ZCell and you can ignore the last several paragraphs entirely.
Now, finally, let’s look at some numbers. The year periods here are a little sloppy for irritating historical reasons. 2018-2019, 2019-2020 and 2020-2021 are all August-based due to Aurora Energy’s previous quarterly billing cycle. The 2021-2022 year starts in late September partly because I had to wait until our new electricity meter was installed in September 2021, and partly because it let me include some nice screenshots when I started writing TANSTAAFL on September 25, 2022. I’ve chosen to make this year (2022-2023) mostly sane, in that it runs from October 1, 2022 through September 30, 2023 inclusive. This is only six days offset from the previous year, but notably makes it much easier to accurately correlate data from the VRM portal with our bills from Aurora. Overall we have five consecutive non-overlapping 12 month periods that are pretty close together. It’s not perfect, but I think it’s good enough to work with for our purposes here.
YeaR
Grid In
Solar In
Total In
Loads
Export
2018-2019
9,031
6,682
15,713
11,827
3,886
2019-2020
9,324
6,468
15,792
12,255
3,537
2020-2021
7,582
6,347
13,929
10,358
3,571
2021-2022
8,531
5,640
14,171
10,849
754
2022-2023
8,936
5,744
14,680
11,534
799
Overall, 2022-2023 had a similar shape to 2021-2022, including the fact that in both these years we missed three weeks of solar generation in late summer. In 2022 this was due to replacing the MPPT, and in 2023 it was because we replaced the roof. In both cases our PV generation was lower than it should have been by an estimated 500-600kW. Hopefully nothing like this happens again in future years.
All of our numbers in 2022-2023 were a bit higher than in 2021-2022. We pulled 4.75% more power from the grid, generated 1.84% more solar, the total power going into the system (grid + solar) was 3.59% higher, our loads used 6.31% more power, and we exported 5.97% more power than the previous year.
I honestly don’t know why our loads used more power this year. Here’s a table showing our consumption for both years, and the differences each month (note that September 2022 is only approximate because of how the years don’t quite line up):
Month
2022
2023
Diff
October
988
873
-115
November
866
805
-61
December
767
965
198
January
822
775
-47
February
638
721
83
March
813
911
98
April
775
1,115
340
May
953
1,098
145
June
1,073
1,149
76
July
1,118
1,103
-15
August
966
1,065
99
September
1,070
964
-116
Here’s a graph:
WTF happened in December and April?!?
Did we use more cooling this December? Did we use more heating this April and May? I dug the nearest weather station’s monthly mean minimum and maximum temperatures out of the BOM Climate Data Online tool and found that there’s maybe a degree or so variance one way or the other each month year to year, so I don’t know what I can infer from that. All I can say is that something happened in December and April, but I don’t know what.
Another interesting thing is that what I referred to as “the energy cost of the system” in TANSTAAFL has gone down. That’s the kW figure below in the “what?” column, which is the difference between grid in + solar in – loads – export, i.e. the power consumed by the system itself. In 2021-2022, that was 2,568 kW, or about 18% of the total power that went into the system. In 2022-2023 it was down to 2,347kWh, or just under 16%:
Year
Grid In
Solar In
Total In
Loads
Export
Total Out
what?
2021-2022
8,531
5,640
14,171
10,849
754
11,603
2,568
2022-2023
8,936
5,744
14,680
11,534
799
12,333
2,347
I suspect the cause of this reduction is that we didn’t spend two and a half months doing lots of grid charging of the battery in 2022-2023. If that’s the case, this again points to the advisability of just letting the system do its thing and not messing with it too much unless you really know you need to.
The last set of numbers I have involve actual money. Here’s what our electricity bills looked like over the past five years:
Year
From Grid
Total Bill
Cost/kWh
2018-2019
9,031
$2,278.33
$0.25
2019-2020
9,324
$2,384.79
$0.26
2020-2021
7,582
$1,921.77
$0.25
2021-2022
8,531
$1,731.40
$0.20
2022-2023
8,936
$1,989.12
$0.22
Note that cost/kWh as I have it here is simply the total dollar amount of our bills divided by the total power drawn from the grid (I’m deliberately ignoring the additional power we use that comes from the sun in this calculation). The bills themselves say “peak power costs $X, off-peak costs $Y, you get $Z back for power exported and there’s a daily supply charge of $SUCKS_TO_BE_YOU”, but that’s all noise. What ultimately matters in my opinion is what I call the effective cost per kilowatt hour, which is why those things are all smooshed together here. The important point is that with our existing solar array we were previously effectively paying about $0.25 per kWh for grid power. After getting the battery and switching to Peak & Off-Peak billing, that went down to $0.20/kWh – a reduction of 20%. Now we’ve inched back up to $0.22/kWh, but it turns out that’s just because power prices have increased. As far as I can tell Aurora Energy don’t publish historical pricing data, so as a public service, I’ll include what I’ve been able to glean from our prior bills here:
July 2023 onwards:
Daily supply charge: $1.26389
Peak: $0.36198/kWh
Off-Peak: $0.16855/kWh
Feed-In Tariff: $0.10869/kWh
July 2022 – July 2023
Daily supply charge: $1.09903
Peak: $0.33399/kWh
Off-Peak: $0.15551/kWh
Feed-In Tariff: $0.08883/kWh
Before July 2022:
Daily supply charge: $0.98
Peak: $0.29852
Off-Peak: $0.139
Feed-In Tariff: $0.06501
It’s nice that the feed-in tariff (i.e. what you get credited when you export power) has gone up quite a bit, but unless you’re somehow able to export 2-3x more power than you import, you’ll never get ahead of the ~20% increase in power prices over the last two years.
Having calculated the effective cost/kWh for grid power, I’m now going to do one more thing which I didn’t think to do during last year’s analysis, and that’s calculate the effective cost/kWh of running our loads, bearing in mind that they’re partially powered from the grid, and partially from the sun. I’ve managed to dig up some old Aurora bills from 2016-2017, back before we put the solar panels on. This should make for an interesting comparison.
Year
From Grid
Total Bill
Grid $/kWh
Loads
Loads $/kWh
2016-2017
17,026
$4,485.45
$0.26
17,026
$0.26
2018-2019
9,031
$2,278.33
$0.25
11,827
$0.19
2019-2020
9,324
$2,384.79
$0.26
12,255
$0.19
2020-2021
7,582
$1,921.77
$0.25
10,358
$0.19
2021-2022
8,531
$1,731.40
$0.20
10,849
$0.16
2022-2023
8,936
$1,989.12
$0.22
11,534
$0.17
The first thing to note is the horrifying 17 megawatts we pulled in 2016-2017. Given the hot water and lounge room heat pump were on a separate tariff, I was able to determine that four of those megawatts (i.e. about 24% of our power usage) went on heating that year. Replacing the crusty old conventional electric hot water system with a Sanden heat pump hot water service cut that in half – subsequent years showed the heating/hot water tariff using about 2MW/year. We obviously also somehow reduced our loads by another ~3MW/year on top of that, but I can’t find the Aurora bills for 2017-2018 so I’m not sure exactly when that drop happened. My best guess is that I probably got rid of some old, always-on computer equipment.
The second thing to note is how the cost of running the loads drops. In 2016-2017 the grid cost/kWh is the same as the loads cost/kWh, because grid power is all we had. From 2018-2021 though, the load cost/kWh drops to $0.19, a saving of about 26%. It remains there until 2021-2022 when we got the battery and it dropped again to $0.16 (another 15% or so). So the big win was certainly putting the solar panels on and swapping the hot water system, with the battery being a decent improvement on top of that.
Further wins are going to come from decreasing our power consumption. In previous posts I had mentioned the need to replace panel heaters with heat pumps, and also that some of our aging computer equipment needed upgrading. We did finally get a heat pump installed in the master bedroom this year, and we replaced the old undersized lounge room heat pump with a new correctly sized unit. This happened on June 30 though, so will have had minimal impact on this years’ figures. Likewise an always-on computer that previously pulled ~100W is now better, stronger and faster in all respects, while only pulling ~50W. That will save us ~438kW of power per year, but given the upgrade happened in mid August, again we won’t see the full effects until later.
I’m looking forward to doing another one of these posts in a year’s time. Hopefully I will have nothing at all interesting to report.
This post is about AmigaOS 3.1.4 on my Amiga 2000. AmigaOS 3.1 from Amiga works fine. However, there are a few interestingly subtle differences between 3.1 and 3.1.4 that are worth knowing about, and they stem from both OS and ROM changes that you need to be aware of.
Let's start with why I reinstalled it.
I did it a few months ago and didn't notice that I had only allocated a 10 megabyte OS partition. Oops. So, I figured I'd install it again before I started doing more work on it, and I remembered the hilarity from last time. This time, though, I took more photos to demonstrate it.
First up, the Amiga 2000. It has the 3.1 ROM from Amiga Forever. I think it doesn't include workbench.library and icons.library in the ROM due to size restrictions. So, you need to have that installed onto your boot media. AmigaOS 3.1.4 does that for you. If you use 3.1 ROMs with earlier installs of AmigaOS then you need to grab those libraries and put them in your SYS: folder yourself.
So, yes I bought some.
Then, the install disk. I have a TF536 in here and 8MB of Zorro-II RAM, hence the large amount of RAM.
Anyway, I started off by re-partitioning the drive using the HDToolBox program. It's supplied on the installation disk. Now, the 3.1.4 ROM includes a scsi.device that works with Amiga 600 style IDE, so I don't need any extra stuff to use the CF adapter on the TF536.
Oops. My boot partition is too small. Let's delete and reinitialise this.
Ok, that's better. Let's save and reboot.
Next - we reboot and reinitialise the disks with a fast format. Here's workbench:
Easy. Now, we run the installer. And, we select "Intermediary" install - or it won't correctly the detect the machine I am installing on, and thus won't install the right version of libraries that are no longer on the 3.1.4 ROM.
And now we begin.
Now after a bunch of disk swaps, it'll ask which version of hardware you have.
The first time I did this on the Amiga 2000 I did the Novice install and it asked for my Amiga 600 disks. Well, obviously I didn't have an Amiga 600. But when I bought the disks I didn't have the modules disks either! I had to sleuth around on the internet to find them. So now I have them for my Amiga 500/1000, 1200 and 2000.
Anyway, it goes and installs the extra bits and pieces.
Finally it's done and I am told that I have a 32 bit CPU (which I do) and I need to do some extra work after reboot (which I will.)
I reboot, and here we are, basic install done. I'm warned again that I should go and install the CPU support stuff.
That's it for now. Next time (if I remember) I'll take photos of installing the CPU support toolkit, the network interface driver and then run AmigaTestKit and SysInfo to show it all together. Then after that it'll be reinstalling the network stack, and then on to music editing stuff.
I (relatively) recently went down the rabbit hole of trying out personal finance apps to help get a better grip on, well, the things you’d expect (personal finances and planning around them).
In the past, I’ve had an off-again-on-again relationship with GNUCash. I did give it a solid go for a few months in 2004/2005 it seems (I found my old files) and I even had the OFX exports of transactions for a limited amount of time for a limited number of bank accounts! Amazingly, there’s a GNUCash port to macOS, and it’ll happily open up this file from what is alarmingly close to 20 years ago.
Back in those times, running Linux on the desktop was even more of an adventure than it has been since then, and I always found GNUCash to be strange (possibly a theme with me and personal finance software), but generally fine. It doesn’t seem to have changed a great deal in the years since. You still have to manually import data from your bank unless you happen to be lucky enough to live in the very limited number of places where there’s some kind of automation for it.
So, going back to GNUCash was an option. But I wanted to survey the land of what was available, and if it was possible to exchange money for convenience. I am not big on the motivation to go and spend a lot of time on this kind of thing anyway, so it had to be easy for me to do so.
For my requirements, I basically had:
Support multiple currencies
Be able to import data from my banks, even if manually
Some kind of reporting and planning tools
Be easy enough to use for me, and not leave me struggling with unknown concepts
The ability to export data. No vendor lock-in
I viewed a mobile app (iOS) as a Nice to Have rather than essential. Given that, my shortlist was:
I’ve used it before, its web site at https://www.gnucash.org/ looks much the same as it always has. It’s Free and Open Source Software, and is thus well aligned with my values, and that’s a big step towards not having vendor lock-in.
I honestly could probably make it work. I wish it had the ability to import transactions from banks for anywhere I have ever lived or banked with. I also wish the UI got to be a bit more consistent and modern, and even remotely Mac like on the Mac version.
Honestly, if the deal was that a web service would pull bank transactions in exchange for ~$10/month and also fund GNUCash development… I’d struggle to say no.
Here’s an option that has been around forever – https://www.quicken.com/ – and one that I figured I should solidly look at. It’s actually one I even spent money on…. before requesting a refund. It’s Import/Export is so broken it’s an insult to broken software everywhere.
Did you know that Quicken doesn’t import the Quicken Interchange Format (QIF), and hasn’t since 2005?
Me, incredulously, when trying out quicken
I don’t understand why you wouldn’t support as many as possible formats that banks export your transaction data as. It cannot possibly be that hard to parse these things, nor can it possibly be code that requires a lot of maintenance.
This basically meant that I couldn’t import data from my Australian Banks. Urgh. This alone ruled it out.
It really didn’t build confidence in ever getting my data out. At every turn it seemed to be really keen on locking you into Quicken rather than having a good experience all-up.
This one was new to me – https://www.wiz.money/ – and had a fancy URL and everything. I spent a bunch of time trying MoneyWiz, and I concluded that it is pretty, but buggy. I had managed to create a report where it said I’d earned $0, but you click into it, and then it gives actual numbers. Not being self consistent and getting the numbers wrong, when this is literally the only function of said app (to get the numbers right), took this out of the running.
It did sync from my US and Australian banks though, so points there.
Intuit used to own Quicken until it sold it to H.I.G. Capital in 2016 (according to Wikipedia). I have no idea if that has had an impact as to the feature set / usability of Quicken, but they now have this Cloud-only product called Mint.
The big issue I had with Mint was that there didn’t seem to be any way to get your data out of it. It seemed to exemplify vendor lock-in. This seems to have changed a bit since I was originally looking, which is good (maybe I just couldn’t find it?). But with the cloud-only approach I wasn’t hugely comfortable with having everything there. It also seemed to be lacking a few features that I was begging to find useful in other places.
It is the only product that links with the Apple Card though. No idea why that is the case.
The price tag of $0 was pretty unbeatable, which does make me wonder where the money is made from to fund its development and maintenance. My guess is that it’s through commission on the various financial products advertised through it, and I dearly hope it is not through selling data on its users (I have no reason to believe it is, there’s just the popular habit of companies doing this).
This is what I’ve settled on. It seemed to be easy enough for me to figure out how to use, sync with an iPhone App, be a reasonable price, and be able to import and sync things from accounts that I have. Oddly enough, nothing can connect and pull things from the Apple Card – which is really weird. That isn’t a Banktivity thing though, that’s just universal (except for Intuit’s Mint).
I’ve been using it for a bit more than a year now, and am still pretty happy. I wish there was the ability to attach a PDF of a statement to the Statement that you reconcile. I wish I could better tune the auto match/classification rules, and a few other relatively minor things.
Periodically in life I’ve had the desire to be somewhat fit, or at least have the benefits that come with that such as not dying early and being able to navigate a mountain (or just the city of Seattle) on foot without collapsing. I have also found that holding myself accountable via data is pretty vital to me actually going and repeatedly doing something.
So, at some point I got myself a Garmin watch. The year was 2012 and it was a Garmin Forerunner 410. It had a standard black/grey LCD screen, GPS (where getting a GPS lock could be utterly infuriatingly slow), a sensor you attached to your foot, a sensor you strap to your chest for Heart Rate monitoring, and an ANT+ dongle for connecting to a PC to download your activities. There was even some open source software that someone wrote so I could actually get data off my watch on my Linux laptops. This wasn’t a smart watch – it was exclusively for wearing while exercising and tracking an activity, otherwise it was just a watch.
However, as I was ramping up to marathon distance running, one huge flaw emerged: I was not fast enough to run a marathon in the time that the battery in my Garmin lasted. IIRC it would end up dying around 3hr30min into something, which at the time was increasingly something I’d describe as “not going for too long of a run”. So, the search for a replacement began!
The year was 2017, and the Garmin fenix 5x attracted me for two big reasons: a battery life to be respected, and turn-by-turn navigation. At the time, I seldom went running with a phone, preferring a tiny SanDisk media play (RIP, they made a new version that completely sucked) and a watch. The attraction of being able to get better maps back to where I started (e.g. a hotel in some strange city where I didn’t speak the language) was very appealing. It also had (what I would now describe as) rudimentary smart-watch features. It didn’t have even remotely everything the Pebble had, but it was enough.
So, a (non-trivial) pile of money later (even with discounts), I had myself a shiny and virtually indestructible new Garmin. I didn’t even need a dongle to sync it anywhere – it could just upload via its own WiFi connection, or through Bluetooth to the Garmin Connect app to my phone. I could also (if I ever remembered to), plug in the USB cable to it and download the activities to my computer.
One problem: my skin rebelled against the Garmin fenix 5x after a while. Like, properly rebelled. If it wasn’t coming off, I wanted to rip it off. I tried all of the tricks that are posted anywhere online. Didn’t help. I even got tested for what was the most likely culprit (a Nickel allergy), and didn’t have one of them, so I (still) have no idea what I’m actually allergic to in it. It’s just that I cannot wear it constantly. Urgh. I was enjoying the daily smart watch uses too!
So, that’s one rather expensive watch that is special purpose only, and even then started to get to be a bit of an issue around longer activities. Urgh.
So the hunt began for a smart watch that I could wear constantly. This usually ends in frustration as anything I wanted was hundreds of $ and pretty much nobody listed what materials were in it apart from “stainless steel”, “may contain”, and some disclaimer about “other materials”, which wasn’t a particularly useful starting point for “it is one of these things that my skin doesn’t like”. As at least if the next one also turned out to cause me problems, I could at least have a list of things that I could then narrow down to what I needed to avoid.
So that was all annoying, with the end result being that I went a long time without really wearing a watch. Why? The search resumed periodically and ended up either with nothing, or totally nothing. That was except if I wanted to get further into some vendor lock-in.
Honestly, the only manufacturer of anything smartwatch like which actually listed everything and had some options was Apple. Bizarre. Well, since I already got on the iPhone bandwagon, this was possible. Rather annoyingly, they are very tied together and thus it makes it a bit of a vendor-lock-in if you alternate phone and watch replacement and at any point wish to switch platforms.
That being said though, it does work well and not irritate my skin. So that’s a bonus! If I get back into marathon level distance running, we’ll see how well it goes. But for more common distances that I’ve run or cycled with it… the accuracy seems decent, HR monitor never just sometimes decides I’m not exerting myself, and the GPS actually gets a lock in reasonable time. Plus it can pair with headphones and be the only thing I take out with me.
A few random notes about things that can make life on macOS (the modern one, as in, circa 2023) better for those coming from Linux.
For various reasons you may end up with Mac hardware with macOS on the metal rather than Linux. This could be anything from battery life of the Apple Silicon machines (and not quite being ready to jump on the Asahi Linux bandwagon), to being able to run the corporate suite of Enterprise Software (arguably a bug more than a feature), to some other reason that is also fine.
My approach to most of my development is to have a remote more powerful Linux machine to do the heavy lifting, or do Linux development on Linux, and not bank on messing around with a bunch of software on macOS that would approximate something on Linux. This also means I can move my GUI environment (the Mac) easily forward without worrying about whatever weird workarounds I needed to do in order to get things going for whatever development work I’m doing, and vice-versa.
Terminal emulator? iTerm2. The built in Terminal.app is fine, but there’s more than a few nice things in iTerm2, including tmuxintegration which can end up making it feel a lot more like a regular Linux machine. I should probably go read the tmux integration best practices before I complain about some random bugs I think I’ve hit, so let’s pretend I did that and everything is perfect.
I tend to use the Mac for SSHing to bigger Linux machines for most of my work. At work, that’s mostly to a Graviton 2 EC2 Instance running Amazon Linux with all my development environments on it. At home, it’s mostly a Raptor Blackbird POWER9 system running Fedora.
Running Linux locally? For all the use cases of containers, Podman Desktop or finch. There’s a GUI part of Podman which is nice, and finch I know about because of the relatively nearby team that works on it, and its relationship to lima. Lima positions itself as WSL2-like but for Mac. There’s UTM for a full virtual machine / qemu environment, although I rarely end up using this and am more commonly using a container or just SSHing to a bigger Linux box.
There’s XCode for any macOS development that may be needed (e.g. when you want that extra feature in UTM or something) I do use Homebrew to install a few things locally.
Last week I had occasion to test deploying ceph-csi on a k3s cluster, so that Kubernetes workloads could access block storage provided by an external Ceph cluster. I went with the upstream Ceph documentation, because assuming everything worked it’d then be really easy for me to say to others “just go do this”.
Everything did not work.
I’d gone through all the instructions, inserting my own Ceph cluster’s FSID and MON IP addresses in the right places, applied the YAML to deploy the provisioner and node plugins, and all the provisioner bits were running just fine, but the csi-rbdplugin pods were stuck in CrashLoopBackOff:
The csi-rbdplugin pod consists of three containers – driver-registrar, csi-rbdplugin, liveness-prometheus – and csi-rbdplugin wasn’t able to load the rbd kernel module:
> kubectl logs csi-rbdplugin-22zjr --container csi-rbdplugin
I0726 10:25:12.862125 7628 cephcsi.go:199] Driver version: canary and Git version: d432421a88238a878a470d54cbf2c50f2e61cdda
I0726 10:25:12.862452 7628 cephcsi.go:231] Starting driver type: rbd with name: rbd.csi.ceph.com
I0726 10:25:12.865907 7628 mount_linux.go:284] Detected umount with safe 'not mounted' behavior
E0726 10:25:12.872477 7628 rbd_util.go:303] modprobe failed (an error (exit status 1) occurred while running modprobe args: [rbd]): "modprobe: ERROR: could not insert 'rbd': Key was rejected by service\n"
F0726 10:25:12.872702 7628 driver.go:150] an error (exit status 1) occurred while running modprobe args: [rbd]
Matching “modprobe: ERROR: could not insert ‘rbd’: Key was rejected by service” in the above was an error on each host’s console: “Loading of unsigned module is rejected”. These hosts all have secure boot enabled, so I figured it had to be something to do with that. So I logged into one of the hosts and ran modprobe rbd as root, but that worked just fine. No key errors, no unsigned module errors. And once I’d run modprobe rbd (and later modprobe nbd) on the host, the csi-rbdplugin container restarted and worked just fine.
So why wouldn’t modprobe work inside the container? /lib/modules from the host is mounted inside the container, the container has the right extra privileges… Clearly I needed to run a shell in the failing container to poke around inside when it was in CrashLoopBackOff state, but I realised I had no idea how to do that. I knew I could kubectl exec -it csi-rbdplugin-22zjr --container csi-rbdplugin -- /bin/bash but of course that only works if the container is actually running. My container wouldn’t even start because of that modprobe error.
Having previously spent a reasonable amount of time with podman, which has podman run, I wondered if there were a kubectl run that would let me start a new container using the upstream cephcsi image, but running a shell, instead of its default command. Happily, there is a kubectl run, so I tried it:
> kubectl run -it cephcsi --image=quay.io/cephcsi/cephcsi:canary --rm=true --command=true -- /bin/bash
If you don't see a command prompt, try pressing enter.
[root@cephcsi /]# modprobe rbd
modprobe: FATAL: Module rbd not found in directory /lib/modules/5.14.21-150400.24.66-default
[root@cephcsi /]# ls /lib/modules/
[root@cephcsi /]#
Ohhh, right, of course, that doesn’t have the host’s /lib/modules mounted. podman run lets me add volume mounts using -v options , so surely kubectl run will let me do that too.
At this point in the story, the notes I wrote last week include an awful lot of swearing.
See, kubectl run doesn’t have a -v option to add mounts, but what it does have is an --overrides option to let you add a chunk of JSON to override the generated pod. So I went back to the relevant YAML and teased out the bits I needed to come up with this monstrosity:
But at least I could get a shell and reproduce the problem:
> kubectl run -it cephcsi-test [honking great horrible chunk of JSON]
[root@cephcsi-test /]# ls /lib/modules/
5.14.21-150400.24.66-default
[root@cephcsi-test /]# modprobe rbd
modprobe: ERROR: could not insert 'rbd': Key was rejected by service
A certain amount more screwing around looking at the source for modprobe and bits of the kernel confirmed that the kernel really didn’t think the module was signed for some reason (mod_verify_sig() was returning -ENODATA), but I knew these modules were fine, because I could load them on the host. Eventually I hit on this:
[root@cephcsi-test /]# ls /lib/modules/*/kernel/drivers/block/rbd*
/lib/modules/5.14.21-150400.24.66-default/kernel/drivers/block/rbd.ko.zst
Wait, what’s that .zst extension? It turns out we (SUSE) have been shipping zstd-compressed kernel modules since – as best as I can tell – some time in 2021. modprobe on my SLE Micro 5.3 host of course supports this:
# grep PRETTY /etc/os-release
PRETTY_NAME="SUSE Linux Enterprise Micro for Rancher 5.3"
# modprobe --version
kmod version 29
+ZSTD +XZ +ZLIB +LIBCRYPTO -EXPERIMENTAL
modprobe in the CentOS Stream 8 upstream cephcsi container does not:
Mystery solved, but I have to say the error messages presented were spectacularly misleading. I later tried with secure boot disabled, and got something marginally better – in that case modprobe failed with “modprobe: ERROR: could not insert ‘rbd’: Exec format error”, and dmesg on the host gave me “Invalid ELF header magic: != \x7fELF”. If I’d seen messaging like that in the first place I might have been quicker to twig to the compression thing.
Anyway, the point of this post wasn’t to rant about inscrutable kernel errors, it was to rant about how there’s no way anyone could be reasonably expected to figure out how to do that --overrides thing with the JSON to debug a container stuck in CrashLoopBackOff. Assuming I couldn’t possibly be the first person to need to debug containers in this state, I told my story to some colleagues, a couple of whom said (approximately) “Oh, I edit the pod YAML and change the container’s command to tail -f /dev/null or sleep 1d. Then it starts up just fine and I can kubectl exec into it and mess around”. Those things totally work, and I wish I’d thought to do that myself. The best answer I got though was to use kubectl debug to make a copy of the existing pod but with the command changed. I didn’t even know kubectl debug existed, which I guess is my reward for not reading the entire manual
So, finally, here’s the right way to do what I was trying to do:
> kubectl debug csi-rbdplugin-22zjr -it \
--copy-to=csi-debug --container=csi-rbdplugin -- /bin/bash
[root@... /]# modprobe rbd
modprobe: ERROR: could not insert 'rbd': Key was rejected by service
(...do whatever other messing around you need to do, then...)
[root@... /]# exit
Session ended, resume using 'kubectl attach csi-debug -c csi-rbdplugin -i -t' command when the pod is running
> kubectl delete pod csi-debug
pod "csi-debug" deleted
In the above kubectl debug invocation, csi-rbdplugin-22zjr is the existing pod that’s stuck in CrashLoopBackOff, csi-debug is the name of the new pod being created, and csi-rbdplugin is the container in that pod that has its command replaced with /bin/bash, so you can mess around inside it.
The July 2023 meeting sparked multiple new topics including Linux security architecture, Debian ports of LoongArch and Risc-V as well as hardware design of PinePhone backplates.
On the practical side, Russell Coker demonstrated running different applications in isolated environment with bubblewrap sandbox, as well as other hardening techniques and the way they interact with the host system. Russell also discussed some possible pathways of hardening desktop Linux to reach the security level of modern Android. Yifei Zhan demonstrated sending and receiving messages with the PineDio USB LoRa adapter and how to inspect LoRa signal with off-the-shelf software defined radio receiver, and discussed how the driver situation for LoRa on Linux might be improved. Yifei then gave a demonstration on utilizing KVM on PinePhone Pro to run NetBSD and OpenBSD virtual machines, more details on running VMs on the PinePhone Pro can be found on this blog post from Yifei.
We also had some discussion of the current state of Mobian and Debian ecosystem, along with how to contribute to different parts of Mobian with a Mobian developer who joined us.
I’ve had a pretty varied experience with photo management on Linux over the past couple of decades. For a while I used f-spot as it was the new hotness. At some point this became…. slow and crashy enough that it was unusable. Today, it appears that the GitHub project warns that current bugs include “Not starting”.
At some point (and via a method I have long since forgotten), I did manage to finally get my photos over to Shotwell, which was the new hotness at the time. That data migration was so long ago now I actually forget what features I was missing from f-spot that I was grumbling about. I remember the import being annoying though. At some point in time Shotwell was no longer was the new hotness and now there is GNOME Photos. I remember looking at GNOME Photos, and seeing no method of importing photos from Shotwell, so put it aside. Hopefully that situation has improved somewhere.
At some point Shotwell was becoming rather stagnated, and I noticed more things stopping to work rather than getting added features and performance. The good news is that there has been some more development activity on Shotwell, so hopefully my issues with it end up being resolved.
One recommendation for Linux photo management was digiKam, and one that I never ended up using full time. One of the reasons behind that was that I couldn’t really see any non manual way to import photos from Shotwell into it.
With tens of thousands of photos (~58k at the time of writing), doing things manually didn’t seem like much fun at all.
As I postponed my decision, I ended up moving my main machine over to a Mac for a variety of random reasons, and one quite motivating thing was the ability to have Photos from my iPhone magically sync over to my photo library without having to plug it into my computer and copy things across.
So…. how to get photos across from Shotwell on Linux to Photos on a Mac/iPhone (and also keep a very keen eye on how to do it the other way around, because, well, vendor lock-in isn’t great).
It would be kind of neat if I could just run Shotwell on the Mac and have some kind of import button, but seeing as there wasn’t already a native Mac port, and that Shotwell is written in Vala rather than something I know has a working toolchain on macOS…. this seemed like more work than I’d really like to take on.
Luckily, I remembered that Shotwell’s database is actually just a SQLite database pointing to all the files on disk. So, if I could work out how to read it accurately, and how to import all the relevant metadata (such as what Albums a photo is in, tags, title, and description) into Apple Photos, I’d be able to make it work.
So… is there any useful documentation as to how the database is structured?
Semi annoyingly, Shotwell is written in Vala, a rather niche programming language that while integrating with all the GObject stuff that GNOME uses, is largely unheard of. Luckily, the database code in Shotwell isn’t too hard to read, so was a useful fallback for when the documentation proves inadequate.
Programming the Mac side of things, it was a good excuse to start looking at Swift, so knowing I’d also need to read a SQLite database directly (rather than use any higher level abstraction), I armed myself with the following resources:
From here, I could work on getting the first half going, the ability to view my Shotwell database on the Mac (which is what I posted a screenshot of back in Feb 2022).
But also, I had to work out what I was doing on the other end of things, how would I import photos? It turns out there’s an API!
A bit of SwiftUI code:
import SwiftUI
import AppKit
import Photos
struct ContentView: View {
@State var favorite_checked : Bool = false
@State var hidden_checked : Bool = false
var body: some View {
VStack() {
Text("Select a photo for import")
Toggle("Favorite", isOn: $favorite_checked)
Toggle("Hidden", isOn: $hidden_checked)
Button("Import Photo")
{
let panel = NSOpenPanel()
panel.allowsMultipleSelection = false
panel.canChooseDirectories = false
if panel.runModal() == .OK {
let photo_url = panel.url!
print("selected: " + String(photo_url.absoluteString))
addAsset(url: photo_url, isFavorite: favorite_checked, isHidden: hidden_checked)
}
}
.padding()
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Combined with a bit of code to do the import (which does look a bunch like the examples in the docs):
import SwiftUI
import Photos
import AppKit
@main
struct SinglePhotoImporterApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
func addAsset(url: URL, isFavorite: Bool, isHidden: Bool) {
// Add the asset to the photo library.
let path = "/Users/stewart/Pictures/1970/01/01/1415446258647.jpg"
let url = URL(fileURLWithPath: path)
PHPhotoLibrary.shared().performChanges({
let addedImage = PHAssetChangeRequest.creationRequestForAssetFromImage(atFileURL: url)
addedImage?.isHidden = isHidden
addedImage?.isFavorite = isFavorite
}, completionHandler: {success, error in
if !success { print("Error creating the asset: \(String(describing: error))") } else
{
print("Imported!")
}
})
}
This all meant I could import a single photo. However, there were some limitations.
There’s the PHAssetCollectionChangeRequest to do things to Albums, so it would solve that problem, but I couldn’t for the life of me work out how to add/edit Titles and Descriptions.
It was so close!
So what did I need to do in order to import Titles and Descriptions? It turns out you can do that via AppleScript. Yes, that thing that launched in 1993 and has somehow survived the transition of m68k based Macs to PowerPC based Macs to Intel based Macs to ARM based Macs.
The Photos dictionary for AppleScript
So, just to make it easier to debug what was going on, I started adding code to my ShotwellImporter tool that would generate snippets of AppleScript I could run and check that it was doing the right thing…. but then very quickly ran into a problem…. it appears that the AppleScript language interpreter on modern macOS has limits that you’d be more familiar with in 1993 than 2023, and I very quickly hit limits where the script would just error out before running (I was out of dictionary size allegedly).
But there’s a new option! Everything you can do with AppleScript you can now do with JavaScript – it’s just even less documented than AppleScript is! But it does work! I got to the point where I could generate JavaScript that imported photos, into all the relevant albums, and set title and descriptions.
In my last post, I wrote about how I taught sesdev (originally a tool for deploying Ceph clusters on virtual machines) to deploy k3s, because I wanted a little sandbox in which I could break learn more about Kubernetes. It’s nice to be able to do a toy deployment locally, on a bunch of VMs, on my own hardware, in my home office, rather than paying to do it on someone else’s computer. Given the k3s thing worked, I figured the next step was to teach sesdev how to deploy Longhorn so I could break that learn more about that too.
Install nfs-client, open-iscsi and e2fsprogs packages on all nodes.
Make an ext4 filesystem on /dev/vdb on all the nodes that have extra disks, then mount that on /var/lib/longhorn.
Use kubectl label node -l 'node-role.kubernetes.io/master!=true' node.longhorn.io/create-default-disk=true to ensure Longhorn does its storage thing only on the nodes that aren’t the k3s master.
Install Longhorn with Helm, because that will install the latest version by default vs. using kubectl where you always explicitly need to specify the version.
Create an ingress so the UI is exposed… from all nodes, via HTTP, with no authentication. Remember: this is a sandbox – please don’t do this sort of thing in production!
So, now I can do this:
> sesdev create k3s --deploy-longhorn
=== Creating deployment "k3s-longhorn" with the following configuration ===
Deployment-wide parameters (applicable to all VMs in deployment):
- deployment ID: k3s-longhorn
- number of VMs: 5
- version: k3s
- OS: tumbleweed
- public network: 10.20.78.0/24
Proceed with deployment (y=yes, n=no, d=show details) ? [y]: y
=== Running shell command ===
vagrant up --no-destroy-on-error --provision
Bringing machine 'master' up with 'libvirt' provider…
Bringing machine 'node1' up with 'libvirt' provider…
Bringing machine 'node2' up with 'libvirt' provider…
Bringing machine 'node3' up with 'libvirt' provider…
Bringing machine 'node4' up with 'libvirt' provider…
[... lots more log noise here - this takes several minutes... ]
=== Deployment Finished ===
You can login into the cluster with:
$ sesdev ssh k3s-longhorn
Longhorn will now be deploying, which may take some time.
After logging into the cluster, try these:
# kubectl get pods -n longhorn-system --watch
# kubectl get pods -n longhorn-system
The Longhorn UI will be accessible via any cluster IP address
(see the kubectl -n longhorn-system get ingress output above).
Note that no authentication is required.
…and, after another minute or two, I can access the Longhorn UI and try creating some volumes. There’s a brief period while the UI pod is still starting where it just says “404 page not found”, and later after the UI is up, there’s still other pods coming online, so on the Volume screen in the Longhorn UI an error appears: “failed to get the parameters: failed to get target node ID: cannot find a node that is ready and has the default engine image longhornio/longhorn-engine:v1.4.1 deployed“. Rest assured thisgoes away in due course (it’s not impossible I’m suffering here from rural Tasmanian internet lag pulling container images). Anyway, with my five nodes – four of which have an 8GB virtual disk for use by Longhorn – I end up with a bit less than 22GB storage available:
21.5 GiB isn’t much, but remember this is a toy deployment running in VMs on my desktop Linux box
Now for the fun part. Longhorn is a distributed storage solution, so I thought it would be interesting to see how it handled a couple of types of failure. The following tests are somewhat arbitrary (I’m really just kicking the tyres randomly at this stage) but Longhorn did, I think, behave pretty well given what I did to it.
Volumes in Longhorn consist of replicas stored as sparse files on a regular filesystem on each storage node. The Longhorn documentation recommends using a dedicated disk rather than just having /var/lib/longhorn backed by the root filesystem, so that’s what sesdev does: /var/lib/longhorn is an ext4 filesystem mounted on /dev/vdb. Now, what happens to Longhorn if that underlying block device suffers some kind of horrible failure? To test that, I used the Longhorn UI to create a 2GB volume, then attached that to the master node:
The Longhorn UI helpfully tells me the volume replicas are on node3, node4 and node1
Then, I ssh’d to the master node and with my 2GB Longhorn volume attached, made a filesystem on it and created a little file:
> sesdev ssh k3s-longhorn
Have a lot of fun...
master:~ # cat /proc/partitions
major minor #blocks name
253 0 44040192 vda
253 1 2048 vda1
253 2 20480 vda2
253 3 44016623 vda3
8 0 2097152 sda
master:~ # mkfs /dev/sda
mke2fs 1.46.5 (30-Dec-2021)
Discarding device blocks: done
Creating filesystem with 524288 4k blocks and 131072 inodes
Filesystem UUID: 3709b21c-b9a2-41c1-a6dd-e449bdeb275b
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Allocating group tables: done
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
master:~ # mount /dev/sda /mnt
master:~ # echo foo > /mnt/foo
master:~ # cat /mnt/foo
foo
Then I went and trashed the block device backing one of the replicas:
> sesdev ssh k3s-longhorn node3
Have a lot of fun...
node3:~ # ls /var/lib/longhorn
engine-binaries longhorn-disk.cfg lost+found replicas unix-domain-socket
node3:~ # dd if=/dev/urandom of=/dev/vdb bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes (105 MB, 100 MiB) copied, 0.486205 s, 216 MB/s
node3:~ # ls /var/lib/longhorn
node3:~ # dmesg|tail -n1
[ 6544.197183] EXT4-fs error (device vdb): ext4_map_blocks:607: inode #393220: block 1607168: comm longhorn: lblock 0 mapped to illegal pblock 1607168 (length 1)
At this point, the Longhorn UI still showed the volume as green (healthy, ready, scheduled). Then, back on the master node, I tried creating another file:
master:~ # echo bar > /mnt/bar
master:~ # cat /mnt/bar
bar
That’s fine so far, but suddenly the Longhorn UI noticed that something very bad had happened:
The volume is still usable, but one of the replicas has failed
Ultimately node3 was rebooted and ended up stalled with the console requesting the root password for maintenance:
Failed to mount /var/lib/longhorn – Can’t find ext4 filesystem
Meanwhile, Longhorn went and rebuilt a third replica on node2:
All green again!
…and the volume remained usable the entire time:
master:~ # echo baz > /mnt/baz
master:~ # ls /mnt
bar baz foo lost+found
That’s perfect!
Looking at the Node screen we could see that node3 was still down:
There may be disk size errors with down nodes (4.87 TiB looks a lot like integer overflow to me)
That’s OK, I was able to fix node3. I logged in on the console and ran mkfs.ext4 /dev/vdb then brought the node back up again.The disk remained unschedulable, because Longhorn was still expecting the ‘old’ disk to be there (I assume based on the UUID stored in /var/lib/longhorn/longhorn-disk.cfg) and of course the ‘new’ disk is empty. So I used the Longhorn UI to disable scheduling for that ‘old’ disk, then deleted it. Shortly after, Longhorn recognised the ‘new’ disk mounted at /var/lib/longhorn and everything was back to green across the board.
So Longhorn recovered well from the backing store of one replica going bad. Next I thought I’d try to break it from the other end by running a volume out of space. What follows is possibly not a fair test, because what I did was create a single Longhorn volume larger than the underlying disks, then filled that up. In normal usage, I assume one would ensure there’s plenty of backing storage available to service multiple volumes, that individual volumes wouldn’t generally be expected to get more than a certain percentage full, and that some sort of monitoring and/or alerting would be in place to warn of disk pressure.
With four nodes, each with a single 8GB disk, and Longhorn apparently reserving 2.33GB by default on each disk, that means no Longhorn volume can physically store more than a bit over 5.5GB of data (see the Size column in the previous screenshot). Given that the default setting for Storage Over Provisioning Percentage is 200, we’re actually allowed to allocate up to a bit under 11GB.
So I went and created a 10GB volume, attached that to the master node, created a filesystem on it, and wrote a whole lot of zeros to it:
…there was a lot of unpleasantness on the master node’s console…
So many I/O errors!
…the replicas became unschedulable due to lack of space…
This doesn’t look good
…and finally the volume faulted:
This really doesn’t look good
Now what?
It turns out that Longhorn will actually recover if we’re able to somehow expand the disks that store the replicas. This is probably a good argument for backing Longhorn with an LVM volume on each node in real world deployments, because then you could just add another disk and extend the volume onto it. In my case though, given it’s all VMs and virtual block devices, I can actually just enlarge those devices. For each node then, I:
Shut it down
Ran qemu-img resize /var/lib/libvirt/images/k3s-longhorn_$NODE-vdb.qcow2 +8G
Started it back up again and ran resize2fs /dev/vdb to take advantage of the extra disk space.
After doing that to node1, Longhorn realised there was enough space there and brought node1’s replica of my 10GB volume back online. It also summarily discarded the other two replicas from the still-full disks on node2 and node3, which didn’t yet have enough free space to be useful:
One usable replica is better than three unusable replicas
As I repeated the virtual disk expansion on the other nodes, Longhorn happily went off and recreated the missing replicas:
Finally I could re-attach the volume to the master node, and have a look to see how many of my zeros were actually written to the volume:
master:~ # cat /proc/partitions
major minor #blocks name
254 0 44040192 vda
254 1 2048 vda1
254 2 20480 vda2
254 3 44016623 vda3
8 0 10485760 sda
master:~ # mount /dev/sda /mnt
master:~ # ls -l /mnt
total 7839764
-rw-r--r-- 1 root root 8027897856 May 3 04:41 big-lot-of-zeros
drwx------ 2 root root 16384 May 3 04:34 lost+found
Recall that dd claimed to have written 9039773696 bytes before it stalled when the volume faulted, so I guess that last gigabyte of zeros is lost in the aether. But, recall also that this isn’t really a fair test – one overprovisioned volume deliberately being quickly and deliberately filled to breaking point vs. a production deployment with (presumably) multiple volumes that don’t fill quite so fast, and where one is hopefully paying at least a little bit of attention to disk pressure as time goes by.
It’s worth noting that in a situation where there are multiple Longhorn volumes, assuming one disk or LVM volume per node, the replicas will all share the same underlying disks, and once those disks are full it seems all the Longhorn volumes backed by them will fault. Given multiple Longhorn volumes, one solution – rather than expanding the underlying disks – is simply to delete a volume or two if you can stand to lose the data, or maybe delete some snapshots (I didn’t try the latter yet). Once there’s enough free space, the remaining volumes will come back online. If you’re really worried about this failure mode, you could always just disable overprovisioning in the first place – whether this makes sense or not will really depend on your workloads and their data usage patterns.
All in all, like I said earlier, I think Longhorn behaved pretty well given what I did to it. Some more information in the event log could perhaps be beneficial though. In the UI I can see warnings from longhorn-node-controller e.g. “the disk default-disk-1cdbc4e904539d26(/var/lib/longhorn/) on the node node1 has 3879731200 available, but requires reserved 2505089433, minimal 25% to schedule more replicas” and warnings from longhorn-engine-controller e.g. “Detected replica overprovisioned-r-73d18ad6 (10.42.3.19:10000) in error“, but I couldn’t find anything really obvious like “Dude, your disks are totally full!”
Later, I found more detail in the engine manager logs after generating a support bundle ([…] level=error msg=”I/O error” error=”tcp://10.42.4.34:10000: write /host/var/lib/longhorn/replicas/overprovisioned-c3b9b547/volume-head-003.img: no space left on device”) so the error information is available – maybe it’s just a matter of learning where to look for it.
We – that is to say the storage team at SUSE – have a tool we’ve been using for the past few years to help with development and testing of Ceph on SUSE Linux. It’s called sesdev because it was created largely for SES (SUSE Enterprise Storage) development. It’s essentially a wrapper around vagrant and libvirt that will spin up clusters of VMs running openSUSE or SLES, then deploy Ceph on them. You would never use such clusters in production, but it’s really nice to be able to easily spin up a cluster for testing purposes that behaves something like a real cluster would, then throw it away when you’re done.
I’ve recently been trying to spend more time playing with Kubernetes, which means I wanted to be able to spin up clusters of VMs running openSUSE or SLES, then deploy Kubernetes on them, then throw the clusters away when I was done, or when I broke something horribly and wanted to start over. Yes, I know there’s a bunch of other tools for doing toy Kubernetes deployments (minikube comes to mind), but given I already had sesdev and was pretty familiar with it, I thought it’d be worthwhile seeing if I could teach it to deploy k3s, a particularly lightweight version of Kubernetes. Turns out that wasn’t too difficult, so now I can do this:
> sesdev create k3s
=== Creating deployment "k3s" with the following configuration ===
Deployment-wide parameters (applicable to all VMs in deployment):
deployment ID: k3s
number of VMs: 5
version: k3s
OS: tumbleweed
public network: 10.20.190.0/24
Proceed with deployment (y=yes, n=no, d=show details) ? [y]: y
=== Running shell command ===
vagrant up --no-destroy-on-error --provision
Bringing machine 'master' up with 'libvirt' provider...
Bringing machine 'node1' up with 'libvirt' provider...
Bringing machine 'node2' up with 'libvirt' provider...
Bringing machine 'node3' up with 'libvirt' provider...
Bringing machine 'node4' up with 'libvirt' provider...
[...wait a few minutes(there's lots more log information output here in real life)
...]
=== Deployment Finished ===
You can login into the cluster with:
$ sesdev ssh k3s
…and then I can do this:
> sesdev ssh k3s
Last login: Fri Mar 24 11:50:15 CET 2023 from 10.20.190.204 on ssh
Have a lot of fun…
master:~ # kubectl get nodes
NAME STATUS ROLES AGE VERSION
master Ready control-plane,master 5m16s v1.25.7+k3s1
node2 Ready 2m17s v1.25.7+k3s1
node1 Ready 2m15s v1.25.7+k3s1
node3 Ready 2m16s v1.25.7+k3s1
node4 Ready 2m16s v1.25.7+k3s1
master:~ # kubectl get pods -A
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system local-path-provisioner-79f67d76f8-rpj4d 1/1 Running 0 5m9s
kube-system metrics-server-5f9f776df5-rsqhb 1/1 Running 0 5m9s
kube-system coredns-597584b69b-xh4p7 1/1 Running 0 5m9s
kube-system helm-install-traefik-crd-zz2ld 0/1 Completed 0 5m10s
kube-system helm-install-traefik-ckdsr 0/1 Completed 1 5m10s
kube-system svclb-traefik-952808e4-5txd7 2/2 Running 0 3m55s
kube-system traefik-66c46d954f-pgnv8 1/1 Running 0 3m55s
kube-system svclb-traefik-952808e4-dkkp6 2/2 Running 0 2m25s
kube-system svclb-traefik-952808e4-7wk6l 2/2 Running 0 2m13s
kube-system svclb-traefik-952808e4-chmbx 2/2 Running 0 2m14s
kube-system svclb-traefik-952808e4-k7hrw 2/2 Running 0 2m14s
…and then I can make a mess with kubectl apply, helm, etc.
One thing that sesdev knows how to do is deploy VMs with extra virtual disks. This functionality is there for Ceph deployments, but there’s no reason we can’t turn it on when deploying k3s:
> sesdev create k3s --num-disks=2
> sesdev ssh k3s
master:~ # for node in \
$(kubectl get nodes -o 'jsonpath={.items[*].metadata.name}') ;
do echo $node ; ssh $node cat /proc/partitions ; done
master
major minor #blocks name
253 0 44040192 vda
253 1 2048 vda1
253 2 20480 vda2
253 3 44016623 vda3
node3
major minor #blocks name
253 0 44040192 vda
253 1 2048 vda1
253 2 20480 vda2
253 3 44016623 vda3
253 16 8388608 vdb
253 32 8388608 vdc
node2
major minor #blocks name
253 0 44040192 vda
253 1 2048 vda1
253 2 20480 vda2
253 3 44016623 vda3
253 16 8388608 vdb
253 32 8388608 vdc
node4
major minor #blocks name
253 0 44040192 vda
253 1 2048 vda1
253 2 20480 vda2
253 3 44016623 vda3
253 16 8388608 vdb
253 32 8388608 vdc
node1
major minor #blocks name
253 0 44040192 vda
253 1 2048 vda1
253 2 20480 vda2
253 3 44016623 vda3
253 16 8388608 vdb
253 32 8388608 vdc
As you can see this gives all the worker nodes an extra two 8GB virtual disks. I suspect this may make sesdev an interesting tool for testing other Kubernetes based storage systems such as Longhorn, but I haven’t tried that yet.
I recently bought an
Energica
Experia - the latest, largest and longest distance of Energica's
electric motorbike models.
The decision to do this rather than build my own was complicated, and I'm
going to mostly skip over the detail of that. At some time I might put it in
another blog post. But for now it's enough to say that I'd accidentally
cooked the motor in my Mark I, the work on the Mark II was going to take ages,
and I was in the relatively fortunate situation of being able to afford the
Experia if I sold my existing Triumph Tiger Sport and the parts for the Mark
II.
For other complicated reasons I was planning to be in Sydney after the weekend
that Bruce at Zen Motorcycles told
me the bike would be arriving. Rather than have it freighted down, and since
I would have room for my riding gear in our car, I decided to pick it up and
ride it back on the Monday. In reconnoitering the route, we discovered that
by pure coincidence Zen Motorcycles is on Euston Road in Alexandria, only
200 metres away from the entrance to WestConnex and the M8. So with one
traffic light I could be out of Sydney.
I will admit to being more than a little excited that morning. Electric
vehicles are still, in 2023, a rare enough commodity that waiting lists can be
months long; I ordered this bike in October 2022 and it arrived in March 2023.
So I'd had plenty of time to build my expectations. And likewise the thought
of riding a brand new bike - literally one of the first of its kind in the
country (it is the thirty-second Experia ever made!) - was a little daunting.
I obtained PDF copies of the manual and familiarised myself with turning the
cruise control on and off, as well as checking and setting the regen braking
levels. Didn't want to stuff anything up on the way home.
There is that weird feeling in those situations of things being both very
ordinary and completely unique. I met Bruce, we chatted, I saw the other
Experia models in the store, met Ed - who had come down to chat with Bruce,
and just happened to be the guy who rode a Harley Davidson Livewire from
Perth to Sydney and then from Sydney to Cape Tribulation and back. He shared
stories from his trip and tips on hypermiling. I signed paperwork, picked up
the keys, put on my gear, prepared myself.
Even now I still get a bit choked up just thinking of that moment. Seeing
that bike there, physically real, in front of me - after those months of
anticipation - made the excitement real as well.
So finally, after making sure I wasn't floating, and making sure I had my
ear plugs in and helmet on the right way round, I got on. Felt the bike's
weight. Turned it on. Prepared myself. Took off. My partner followed
behind, through the lights, onto the M8 toward Canberra. I gave her the
thumbs up.
We planned to stop for lunch at Mittagong, while the NRMA still offers the
free charger at the RSL there. One lady was charging her Nissan Leaf on the
ChaDeMo side; shortly after I plugged in a guy arrived in his Volvo XC40
Recharge. He had the bigger battery and would take longer; I just needed a
ten minute top up to get me to Marulan.
I got to Marulan and plugged in; a guy came thinking he needed to tell the
petrol motorbike not to park in the electric vehicle bay, but then realised
that the plug was going into my bike. Kate headed off, having charged up as
well, and I waited another ten minutes or so to get a bit more charge. Then
I rode back.
I stopped, only once more - at Mac's Reef Road. I turned off and did a U
turn, then waited for the traffic to clear before trying the bike's
acceleration. Believe me when I say this bike will absolutely do a 0-100km/hr
in under four seconds! It is not a light bike, but when you pull on the power
it gets up and goes.
Here is my basic review, given that experience and then having ridden it for
about ten weeks around town.
The absolute best feature of the Energica Experia is that it is perfectly
comfortable riding around town. Ease on the throttle and it gently takes off
at the traffic lights and keeps pace with the traffic. Ease off, and it
gently comes to rest with regenerative braking and a light touch on the rear
brake after stopping to hold it still. If you want to take off faster, wind
the throttle on more. It is not temperamental or twitchy, and you have no
annoying gears and clutch to balance.
In fact, I feel much more confident lane filtering, because before I would
have to have the clutch ready and be prepared to give the Tiger Sport lots of
throttle lest I accidentally stall it in front of an irate line of traffic.
With the Experia, I can simply wait peacefully - using no power - and then
when the light goes green I simply twist on the throttle and I am away ahead
of even the most aggressive car driver.
It is amazingly empowering.
I'm not going to bore you with the stats - you can probably look them up
yourself if you care. The main thing to me is that it has DC fast charging,
and watching 75KW go into a 22.5KWHr battery is just a little bit terrifying
as well as incredibly cool. The stated range of 250km on a charge at highway
speeds is absolutely correct, from my experience riding it down from Sydney.
And that plus the fast charging means that I think it is going to be quite
reasonable to tour on this bike, stopping off at fast or even mid-level
chargers - even a boring 22KW charger can fill the battery up in an hour.
The touring group I travel with stops often enough that if those stops can be
top ups, I will not hold anyone up.
Some time in the near future I hope to have a nice fine day where I can take
it out on the Cotter Loop. This is an 80km stretch of road that goes west of
Canberra into the foothills of the Brindabella Ranges, out past the Deep
Space Tracking Station and Tidbinbilla Nature Reserve. It's a great
combination of curving country roads and hilly terrain, and reasonably well
maintained as well. I did that on the Tiger Sport, with a GoPro, before I
sold it - and if I can ever convince PiTiVi to actually compile the video
from it I will put that hour's ride up on a platform somewhere.
I want to do that as much to show off Canberra's scenery as to show off the
bike.
And if the CATL battery capacity improvement comes through to the rest of the
industry, and we get bikes that can do 400km to 500km on a charge, then
electric motorbike touring really will be no different to petrol motorbike
touring. The Experia is definitely at the forefront of that change, but it
is definitely possible on this bike.
Rustup (the community package manage for the Rust language) was starting to really suffer : CI times were up at ~ one hour.
We’ve made some strides in bringing this down.
Caching factory for test scenarios
The first thing, which achieved about a 30% reduction in test time was to stop recreating all the test context every time.
Rustup tests the download/installation/upgrade of distributions of Rust. To avoid downloading gigabytes in the test suite, the suite creates mocks of the published Rust artifacts. These mocks are GPG signed and compressed with multiple compression methods, both of which are quite heavyweight operations to perform – and not actually the interesting code under test to execute.
Previously, every test was entirely hermetic, and usually the server state was also unmodified.
There were two cases where the state was modified. One, a small number of tests testing error conditions such as GPG signature failures. And two, quite a number of tests that were testing temporal behaviour: for instance, install nightly at time A, then with a newer server state, perform a rustup update and check a new version is downloaded and installed.
We’re partway through this migration, but compare these two tests:
The former version mutates the date with set_current_dist_date; the new version uses two scenarios, one for the earlier time, and one for the later time. This permits the server state to be constructed only once. On a per-test basis it can move as much as 50% of the time out of the test.
Single binary for the integration test suite
The next major gain was moving from having 14 separate integration test binaries to just one. This reduces the link cost of linking the test binaries, all of which link in the same library. It also permits us to see unused functions in our test support library, which helps with cleaning up cruft rather than having it accumulate.
Hard linking rather than copying ‘rustup-init’
Part of the test suite for each test is setting up an installed rustup environment. Why not start from scratch every time? Well, we obviously have tests that do that, but most tests are focused on steps beyond the new-user case. Setting up an installed rustup environment has a few steps, but particular ones are copying a binary of rustup into the test sandbox, and hard linking it under various names: cargo, rustc, rustup etc.
A debug build of rustup is ~20MB. Running 400 tests means about 8GB of IO; on some platforms most of that IO won’t hit disk, on others it will.
In review now is a PR that changes the initial copy to a hardlink: we hardlink the rustup-init built by cargo into each test, and then hardlink that to the various binaries. That saves 8GB of IO, which isn’t much from some perspectives, but it adds pressure on the page cache, and is wasted work. One wrinkle is a very low max-links limit on NTFS of 1023; to mitigate that we count the links made to rustup-init and generate a new inode for the original to avoid failures happening.
Future work
In GitHub actions this lowers our test time to 19m for Linux, 24m for Windows, which is a lot better but not great.
I plan on experimenting with separate actions for building release artifacts and doing CI tests – at the moment we have the same action do both, but they don’t share artifacts in the cache in any meaningful way, so we can probably gain parallelism there, as well as turning off release builds entirely for CI.
We should finish the cached test context work and use it everywhere.
Also we’re looking at having less integration tests and more narrow close to the code tests.
Back in 2012, I received a box of eight hundred openSUSE 12.1 promo DVDs, which I then set out to distribute to local Linux users’ groups, tech conferences, other SUSE crew in Australia, and so forth. I didn’t manage to shift all 800 DVDs at the time, and I recently rediscovered the remaining three hundred and eighty four while installing some new shelves. As openSUSE 12.1 went end of life in May 2013, it seemed likely the DVDs were now useless, but I couldn’t bring myself to toss them in landfill. Instead, given last week was Hack Week, I decided to use them for an art project. Here’s the end result:
Geeko mosaic made of cut up openSUSE DVDs, on a 900mm x 600mm piece of plywood
Making that mosaic was extremely fiddly. It’s possibly the most annoying Hack Week project I’ve ever done, but I’m very happy with the outcome
The backing is a piece of 900mm x 600mm x 6mm plywood, primed with some leftover kitchen and bathroom undercoat, then spray pained black. I’d forgotten how bad spray paint smells, but it makes for a nice finish. To get the Geeko shape, I took the official openSUSE logo, then turned it into an outline in Inkscape, saved that as a PNG, opened it in GIMP, and cut it into nine 300mm x 200mm pieces which I then printed on A4 paper, stuck together with tape, and cut out to make a stencil. Of course, the first time I did that, nothing quite lined up, so I had to reprint it but with “Ignore page margins” turned off and “Draw crop marks” turned on, then cut the pages down along the crop marks before sticking them together the second time. Then I placed the stencil on the backing, glued the eye down (that just had to be made from the centre of a DVD!) and started laying out cut up DVD shards.
Geeko mosaic work in progress
I initially tried cutting the DVDs with tin snips, which is easy on the hands, but had a tendency to sometimes warp the DVD pieces and/or cause them to delaminate, so I reverted to a large pair of scissors which was more effort but ultimately less problematic.
After placing the pieces that made up the head, tail, feet and spine, and deciding I was happy with how they looked, I glued each piece down with superglue. Think: carefully pick up DVD shard without moving too many other shards, turn over, dab on a few tiny globs of superglue, lower into place, press for a few seconds, move to next piece. Do not get any superglue on your fingers, or you’ll risk sticking your fingers together and/or make a gluey mess on the shiny visible side of the DVD shards.
It was another three sessions of layout-then-glue-down to fill in the body. I think I stuck my fingers together about six, or eight, or maybe twenty times. Also, despite my best efforts to get superglue absolutely nowhere near the stencil at all, when I removed the stencil, it had stuck to the backing in several places. I managed to scrape/cut that off with a combination of fingernails, tweezers, and the very sharp knife in my SLE 12 commemorative Leatherman tool, then touched up the remaining white bits with a fine point black Sharpie.
SLE 12 commemorative Leatherman tool (it seemed appropriate to use this)
Judging from the leftover DVD centre pieces, this mosaic used about 12 DVDs in all, which isn’t very many considering my initial stash. I had a few other ideas for the remainder, mostly involving hanging them up somehow, which I messed around with earlier on while waiting for the paint to dry on the plywood.
One (failed) idea was to use a cutting wheel on my Dremel tool to slice half way through a few DVDs, then slot them into each other to make a hanging thingy that would spin in the wind. I was unable to make a smooth/straight enough cut for this to work, and superglue doesn’t bridge gaps. You can maybe get an idea of what I was aiming at from this photo:
Four DVDs slotted into each other vertically, kinda, one with nasty superglue smear
My wife had an idea for a better way to do this, which is to take a piece of dowel, cut slots in the sides, and glue DVD halves into the slots using Araldite (that’s an epoxy resin, in case you didn’t grow up with that brand name). I didn’t get around to trying this, but I reckon she’s onto something. Next time I’m at the hardware store, I’ll try to remember to pick up some suitably sized dowel.
I did make one somewhat simpler hanging thingy, which I call “Geeko’s Tail (Uncurled)”. It’s just DVDs superglued together on the flat, hanging from fishing line, but I think it’s kinda cool:
No, it’s not an upside down question mark, it’s “Geeko’s Tail (Uncurled)”
Also, I’ve discovered that Officeworks has an e-waste recycling program, so any DVDs I don’t use in future projects needn’t go to landfill.
I gave my amiga 1000 keyboard cable to a friend so she could complete her Amiga 1000 setup. I then ordered some replacement RJ12 cables (4 wires!) to get mine working.
But they didn't.
Let's talk about why.
Firstly - yes, the cable is a RJ12 4P4C rollover cable. Ie, if you hold both connectors up next to each other and aligned the same way, the left hand pins are numbered "1-2-3-4" and the right hand connector is "4-3-2-1". Don't get this backwards or you'll end up reversing the power to the keyboard and damage stuff. It seems most phone cables are 4-wire RJ-12 and rollover pinout, but it's good to double check.
This is different to the early Macintosh keyboard - the RJ12 cable there is straight through. "1-2-3-4" goes to "1-2-3-4".
But it didn't work. I pulled apart the keyboard and started debugging it ... way too hard. The TL;DR is this. When I powered the keyboard from a 5v dedicated supply it was pulling 5v at around 125mA.
The cable I was using, straight from the bag:
The pinout is fine, but each leg has a 40 ohm resistance. There's no way to get 125mA out of 5v at 80 ohm resistance (+5v and GND, 40 ohms each.) The voltage on the keyboard side was closer to 2v.
The one I build/crimped until it worked:
18 ohms now, and can supply ~ 250mA. It was happy with this.
So if you're looking to replace a keyboard cable with an RJ11/RJ12 from Amazon or some other store, double check the pinout, double check that there's 4 wires in the cable, and double-check the series resistance!
I have long said “Long Malaysians, Short Malaysia” in conversation to many. Maybe it took me a while to tweet it, but this was the first example: Dec 29, 2021. I’ve tweeted it a lot more since.
Malaysia has a 10th Prime Minister, but in general, it is a very precarious partnership. Consider it, same shit, different day?
5/n: Otherwise, there will be no change.
So change via “purported democracy” is never going to happen with a country like Malaysia, rotten to the core. It is a crazy dream.
I just have to get off the Malaysian news diet. Malaysians elsewhere, are generally very successful. Malaysians suffering by their daily doldrums, well, they just need to wake up, see the light, and succeed.
In the end, as much as people paraphrase, ask not what the country can do for you, legitimately, this is your life, and you should be taking good care of yourself and your loved ones. You succeed, despite of. Politics and the state happens, regardless of.
Me, personally? Ideas are abound for how to get Malaysians who see the light, to succeed elsewhere. And if I read, and get angry at something (tweet rage?), I’m going to pop RM50 into an investment account, which should help me get off this poor habit. I’ll probably also just cut subscriptions to Malaysian news things… Less exposure, is actually better for you. I can’t believe that it has taken me this long to realise this.
I did poorly blogging last year. Oops. I think to myself when I read, This Thing Still On?, I really have to do better in 2023. Maybe the catalyst is the fact that Twitter is becoming a shit show. I doubt people will leave the platform in droves, per se, but I think we are coming back to the need for decentralised blogs again.
I have 477 days to becoming 40. I ditched the Hobonich Techo sometime in 2022, and just focused on the Field Notes, and this year, I’ve got a Monocle x Leuchtturm1917 + Field Notes combo (though it seems my subscription lapsed Winter 2022, I should really burn down the existing collection, and resubscribe).
2022 was pretty amazing. Lots of work. Lots of fun. 256 days on the road (what a number), 339,551km travelled, 49 cities, 20 countries.
The getting back into doing, and not being afraid of experimenting in public is what 2023 is all about. The Year of The Rabbit is upon us tomorrow, hence why I don’t mind a little later Hello 2023 :)
Get back into the habit of doing. And publishing by learning and doing. No fear. Not that I wasn’t doing, but its time to be prolific with what’s been going on.
Wait, no. I never had one as a kid, I had access to a couple of BBC micros in my primary school for playing a pirate / math educational game that I have since not found online, and I've never really wanted one. Until a close friend's birthday - at which point I got them one.
And then we fell down a rabbit hole together.
So, I bought a dead Electron motherboard. Here you go.
And the ULA - quite a bit of damaged tracks there.
Yes, the ULA is supposedly dead, like a lot of these Electron PCBs. My goal was to strip the PCB of components and make a replica rev4 board. However, first up, i wanted to see if i could repair it.
So, I took off the ULA and fixed up the busted pins. Some copper tape and solder did the trick. One pin was completely missing, and that was quite a challenge to get right.
Then I socketed the 6502 CPU and BASIC/OS ROM. The 6502 was already socketed but the soldering job was pretty bad. I tossed the nice machined socket because it was soldered in bad and I didn't want to clean up all the bad solder from on top of the pins, and I instead just whacked a cheap socket down to test.
Then I powered it up.
Oops. Guess I have a working Acorn Electron. Well, I don't have a case, power supply or keyboard. Guess I'm going to have to make a keyboard for it.
I like using Catalyst Cloud to host some of my personal sites. In the past I used to use CAcert for my TLS certificates, but more recently I've been using Let's Encrypt for my TLS certificates as they're trusted in all browsers. Currently the LoadBalancer as a Service (LBaaS) in Catalyst Cloud doesn't have built in support for Let's Encrypt. I could use an apache2/nginx proxy and handle the TLS termination there and have that manage the Let's Encrypt lifecycle, but really, I'd rather use LBaaS.
So I thought I'd set about working out how to get Dehydrated (the Let's Encrypt client I've been using) to drive LBaaS (known as Octavia). I figured this would be of interest to other people using Octavia with OpenStack in general, not just Catalyst Cloud.
There's a few things you need to do. These instructions are specific to Debian:
Install and configure Dehydrated to create the certificates for the domain(s) you want.
apt install barbican
Create the LoadBalancer (use the API, ClickOps, whatever), just forward port 80 for now (see sample Apache configs below).
Save the sample hook.sh below to /etc/dehydrated/hook.sh, you'll probably need to customise it, mine is a bit more complicated!
Insert the UUID of your LoadBalancer in hook.sh where LB_LISTENER is set.
Create /etc/dehydrated/catalystcloud/password as described in hook.sh
Save OpenRC file from the Catalyst Cloud dashboard as /etc/dehydrated/catalystcloud/openrc.sh
Install jq, openssl and the openstack tools, on Debian this is:
You should be able to rename the latest certs /var/lib/dehydrated/certs/$DOMAIN and then run dehydrated -c to have it reissue and then deploy a cert.
As we're using HTTP-01 Challenge Type here, you need to have the LoadBalancer forwarding port 80 to your website to allow for the challenge response. It is good practice to have a redirect to HTTPS, here's an example virtual host for Apache:
You all also need this in /etc/apache2/conf-enabled/letsencrypt.conf:
Alias /.well-known/acme-challenge /var/lib/dehydrated/acme-challenges
<Directory /var/lib/dehydrated/acme-challenges>
Options None
AllowOverride None
# Apache 2.x
<IfModule !mod_authz_core.c>
Order allow,deny
Allow from all
</IfModule>
# Apache 2.4
<IfModule mod_authz_core.c>
Require all granted
</IfModule>
</Directory>
And that should be all that you need to do. Now, when Dehydrated updates your certificate, it should update your LoadBalancer as well!
Sample hook.sh:
deploy_cert() {
local DOMAIN="${1}" KEYFILE="${2}" CERTFILE="${3}" FULLCHAINFILE="${4}" \
CHAINFILE="${5}" TIMESTAMP="${6}"
shift 6
# File contents should be:
# export OS_PASSWORD='your password in here'
. /etc/dehydrated/catalystcloud/password
# OpenRC file from the Catalyst Cloud dashboard
. /etc/dehydrated/catalystcloud/openrc.sh --no-token
# UUID of the LoadBalancer to be managed
LB_LISTENER='xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
# Barbican uses P12 files, we need to make one.
P12=$(readlink -f $KEYFILE \
| sed -E 's/privkey-([0-9]+)\.pem/barbican-\1.p12/')
openssl pkcs12 -export -inkey $KEYFILE -in $CERTFILE -certfile \
$FULLCHAINFILE -passout pass: -out $P12
# Keep track of existing certs for this domain (hopefully no more than 100)
EXISTING_URIS=$(openstack secret list --limit 100 \
-c Name -c 'Secret href' -f json \
| jq -r ".[]|select(.Name | startswith(\"$DOMAIN\"))|.\"Secret href\"")
# Upload the new cert
NOW=$(date +"%s")
openstack secret store --name $DOMAIN-$TIMESTAMP-$NOW -e base64 \
-t "application/octet-stream" --payload="$(base64 < $P12)"
NEW_URI=$(openstack secret list --name $DOMAIN-$TIMESTAMP-$NOW \
-c 'Secret href' -f value) \
|| unset NEW_URI
# Change LoadBalancer to use new cert - if the old one was the default,
# change the default. If the old one was in the SNI list, update the
# SNI list.
if [ -n "$EXISTING_URIS" ]; then
DEFAULT_CONTAINER=$(openstack loadbalancer listener show $LB_LISTENER \
-c default_tls_container_ref -f value)
for URI in $EXISTING_URIS; do
if [ "x$URI" = "x$DEFAULT_CONTAINER" ]; then
openstack loadbalancer listener set $LB_LISTENER \
--default-tls-container-ref $NEW_URI
fi
done
SNI_CONTAINERS=$(openstack loadbalancer listener show $LB_LISTENER \
-c sni_container_refs -f value | sed "s/'//g" | sed 's/^\[//' \
| sed 's/\]$//' | sed "s/,//g")
for URI in $EXISTING_URIS; do
if echo $SNI_CONTAINERS | grep -q $URI; then
SNI_CONTAINERS=$(echo $SNI_CONTAINERS | sed "s,$URI,$NEW_URI,")
openstack loadbalancer listener set $LB_LISTENER \
--sni-container-refs $SNI_CONTAINERS
fi
done
# Remove old certs
for URI in $EXISTING_URIS; do
openstack secret delete $URI
done
fi
}
HANDLER="$1"; shift
#if [[ "${HANDLER}" =~ ^(deploy_challenge|clean_challenge|sync_cert|deploy_cert|deploy_ocsp|unchanged_cert|invalid_challenge|request_failure|generate_csr|startup_hook|exit_hook)$ ]]; then
if [[ "${HANDLER}" =~ ^(deploy_cert)$ ]]; then
"$HANDLER" "$@"
fi
It’s been a little over a year since our Redflow ZCell battery and Victron Energy inverter/charger kit were installed on our existing 5.94kW solar array. Now that we’re past the Southern Hemisphere spring equinox it seems like an opportune time to review the numbers and try to see exactly how the system has performed over its first full year. For background information on what all the pieces are and what they do, see my earlier post, Go With The Flow.
As we look at the figures for the year, it’s worth keeping in mind what we’re using the battery for, and how we’re doing it. Naturally we’re using it to store PV generated electricity for later use when the sun’s not shining. We are also charging the battery from the grid at certain times so it can be drawn down if necessary during peak times, for example I set up a small overnight charge to ensure there was power for the weekday morning peak, when the sun isn’t really happening yet, but grid power is more than twice as expensive. More recently in the winter months, I experimented with keeping the battery full with scheduled charges during most non-peak times. This involved quite a bit more grid charging, but got us through a couple of three hour grid outages without a hitch during some severe weather in August.
I spent some time going through data from the VRM portal for the last year, and correlating that with current bills from Aurora energy, and then I tried to compare our last year of usage with a battery, to the previous three years of usage without a battery. For reasons that will become apparent later, this turned out to be a massive pain in the ass, so I’m going to start by looking only at what we can see in the VRM portal for the past year.
The VRM portal has three summary views: System Overview, Consumption and Solar. System Overview tells us overall how much total power was pulled from the grid, how much was exported to the grid, how much was produced locally, and how much was consumed by our loads. The Consumption view (which I wish they’d named “Loads”, because I think that would be clearer) gives us the same consumption figure, but tells us how much of that came from the grid, vs. what came from the battery vs. what came from solar. The Solar view tells us how much PV generation went to the grid, how much went to the battery, and how much was used directly. There is some overlap in the figures from these three views, but there are also some interesting discrepancies, notably: the “From Grid” and “To Grid” figures shown under System Overview are higher than what’s shown in the Consumption and Solar views. But, let’s start by looking at the Consumption and Solar views, because those tell us what the system gives us, and what we’re using. I’ll come back after that to the System Overview, which is where things start to get weird and we discover what the system costs to run.
The VRM portal lets you chose any date range you like to get historical figures and bar charts. It also gives you pie charts of the last 24 hours, 7 days, 30 days and 365 days. To make the figures and bar charts match the pie charts, the year we’re analysing starts at 4pm on September 25, 2021 and ends at 4pm on September 25, 2022, because that’s exactly when I took the following screenshots. This means we get a partial September at each end of the bar chart. I’m sorry about that.
Here’s the Consumption view:
Consumption view from VRM portal, 2021-09-25 16:00 – 2022-09-25 16:00
This shows us that in the last 12 months, our loads consumed 10,849kWh of electricity. Of that, 54% (5,848kWh) came from the grid, 23% (2,506kWh) came direct from solar PV and the final 23% (2,494kWh) came from the battery.
From the rough curve of the bar chart we can see that our consumption is lower in the summer months and higher in the winter months. I can’t say for certain, but I have to assume that’s largely due to heating. The low in February was 638kWh (an average of 22.8kWh/day). The high in July was 1,118kWh (average 36kWh/day).
Now let’s look at the Solar view:
Solar view from VRM portal, 2021-09-25 16:00 – 2022-09-25 16:00
In that same time period we generated 5,640kWh with our solar array, of which 44% (2,506kWh) was used directly by our loads, 43% (2,418kWh) went into the battery and 13% (716kWh) was exported to the grid.
Unsurprisingly our generation is significantly higher in summer than in winter. We got 956kWh (average 30kWh/day) in December but only 161kWh (5.3kWh/day) in June. Peak summer figures like that mean we’ll theoretically be able to do without grid power at all during that period once we get a second ZCell (note that we’re still exporting to the grid in December – that’s because we’ve got more generation capacity than storage). The winter figures clearly indicate that there’s no way we can provide anywhere near all our own power at that time of year with our current generation capacity and loads.
Now look closely at the summer months (December, January and February). There should be a nice curve evident there from December to March, but instead January and February form a weird dip. This is because we were without solar generation for three weeks from January 20 – February 11 due to replacing a faulty MPPT. Based on figures from previous years, I suspect we lost 500-600kWh of potential generation in that period.
Another interesting thing is that if we compare “To Battery” on the Solar view (2,418kWh) with “From Battery” on the Consumption view (2,494kWh), we see that our loads consumed 76kWh more from the battery than we actually put into it with solar generation. This discrepancy is due to the fact that in addition to charging the battery from solar, we’ve also been charging it from the grid at certain times, but the amount of power sent to the battery from the grid isn’t broken out explicitly anywhere in the VRM portal.
Now let’s look at the System Overview:
System Overview view from VRM portal, 2021-09-25 16:00 – 2022-09-25 16:00
Here we see the same figures for “Production” (5,640kWh) and “Consumption” (10,849kWh) as were in the Consumption and Solar views, and the bar chart shows the same consumption and generation curves (ignore the blue overlay and line which indicate battery minimum/maximum and average state of charge – that information is largely meaningless at this scale, given we cycle the battery completely every day).
Now look at “To Grid” and “From Grid”. “To Grid” is 754 kWh, i.e. we somehow sent 38kWh more to the grid than came from solar. “From Grid”, at 8,531kWh, is a whopping 2,683kWh more than the 5,848kWh grid power consumed by our loads (i.e. close to half as much again).
So, what’s going on here?
One factor is that we’re charging the battery from the grid at certain times. Initially that was a few hours overnight and a few hours in the afternoon on weekdays, although the afternoon charge is obviously also provided by the solar if the sun is shining. For all of July, August and most of September though I was using a charge schedule to keep the battery full except for peak times and maintenance cycle nights, which meant quite a bit more grid charging overnight than earlier in the year, as well as grid charging most of the day during days with no or minimal sunshine. Grid power sent to the battery isn’t visible in the “From Grid” figure on the Consumption view – that view shows only our loads, i.e. the equipment the system is powering – but it is part of the “From Grid” figure in the System Overview.
Similarly, some of the power we export to the grid is actually exported from the battery, as opposed to being exported from solar generation. That usually only happens during maintenance cycles when our loads aren’t enough to draw the battery down at the desired discharge rate. But again, same thing, that figure is present here on the system overview page as part of “To Grid”, but of course is not part of the “To Grid” figure on the Solar view.
Another factor is that the system itself needs some amount of power to operate. The Victron kit (the MultiPlus II Inverter/Chargers, the Cerbo GX, the MPPT) use some small amount of power themselves. The ZCell battery also requires power to operate its pumps and fans. When the sun is out this power can of course come from solar. When solar power is not available, power to run the system needs to come from some combination of the remaining charge in the battery, and the grid.
On that note, I did a little experiment to see how much power the system uses just to operate. On July 9 (which happened to be a maintenance cycle day), I disabled all scheduled battery charges, and I shut off the DC isolators for the solar PV, so the battery would remain online (pumps and fans running) but empty for all of July 10. The following day I went and checked the figures on the System Overview, which showed we drew 35kWh, but that our consumption was 33kWh. So, together, the battery doing nothing other than running its pumps and fans, plus the Multis doing nothing other than passing grid power through, used 2kWh of power in 24 hours. Over a year, that’s 730kWh. As mentioned above, ordinarily some of that will be sourced from mains and some from solar, but if we look at the total power that came into the system as a whole (5,640kWh from solar + 8,531kWh from the grid = 14,171kWh), 730kWh is just slightly over 5% of that.
The final factor in play is that a certain amount of power is naturally lost due to conversion at various points. The ZCell has a maximum 80% DC-DC stack efficiency, meaning in the absolute best case if you want to get 10kW out of it, you have to put 12.5kW in. In reality you’ll never hit the best case: the lifetime charge and discharge figures the BMS currenly shows for our ZCell are 4,423 and 3,336kWh respectively, which is a bit over 75%. The Multis have a maximum efficiency of 96% when doing their invert/charge dance, so if we grid charge the battery, we lose at least 4% on the way in, and at least 4% on the way out as well, going to and from AC/DC. Again, in reality that loss will be higher than 4% each way, because 96% is the maximum efficiency.
A bunch of the stuff above just doesn’t apply to the previous system with the ABB inverter and no battery. I also don’t have anything like as much detailed data to go on for the old system, which makes comparing performance with the new system fiendishly difficult. The best comparison I’ve been able to come up with so far involves looking at total power input to the system (power from grid plus solar generation), total consumption by loads (i.e. actual locally usable power), and total power exported.
Prior to the Victron gear and Redflow battery installation, I had grid import and export figures from my Aurora Energy bills, and I had total generation figures from the ABB inverter. From this I can synthesise what are hopefully reasonably accurate load consumption figures by adding grid input to total PV generation minus grid export.
I had hoped to do this analysis on a quarterly basis to line up with Aurora bills, because then I would also be able to see how seasonal solar generation and usage went up and down. Unfortunately the billing for 2020 and 2021 was totally screwed up by the COVID-19 pandemic, because there were two quarters during which nobody was coming out to read the electricity meter. The bills for those quarters stated estimated usage (i.e. were wrong, especially given they estimated grid export as zero), with subsequent quarters correcting the figures. I have no way to reliably correlate that mess with my PV generation figures, except on an annual basis. Also, using billing periods from pre-battery years, the closest I can get to the September 25 based 2021-2022 year I’m looking at now is billing periods starting and ending in mid-August. But, that’s close enough. We’ve still got four pretty much back-to-back 12 month periods to look at.
Year
Grid In
Solar In
Total In
Loads
Export
2018-2019
9,031
6,682
15,713
11,827
3,886
2019-2020
9,324
6,468
15,792
12,255
3,537
2020-2021
7,582
6,347
13,929
10,358
3,571
2021-2022
8,531
5,640
14,171
10,849
754
One thing of note here is that in the 2018-2019 and 2019-2020 years, our annual consumption was pretty close to 12MWh, whereas in 2020-2021 and 2021-2022 it was closer to 10.5MWh. If I had to guess, I’d say that ~1.5MWh/year drop is due to a couple of pieces of computer equipment that were previously always on, now mostly running in standby mode except when actually needed. A couple of hundred watts constant draw is a fair whack of power over the course of a year. Another thing to note is the big drop in power exported in 2021-2022, because most of our solar generation is now used locally.
The thing that freaked me out when looking at these figures is that in the battery year, while our loads consumed 491kWh more than in the previous non-battery year, we pulled 949kWh more power in from the grid! This is the opposite of what I had expected to see, especially having previously written:
In the eight months the system has been running we’ve generated 4631kWh of electricity and “only” sent 588kWh to the grid, which means we’ve used 87% of what we generated locally – much better than the pre-battery figure of 45%. I suspect we’ve reduced the amount of power we pull from the grid by about 30% too, but I’ll have to wait until we have a full year’s worth of data to be sure.
When I wrote that, I was looking at August 31, 2021 through April 27, 2022, and comparing that to the August 2020 to May 2021 grid power figures from my old Aurora bills. The mistake I must have made back then was to look at “From Grid” on the Consumption view, rather than “From Grid” on the System Overview. I’ve just done this exercise again, and the total grid draw from our Aurora bills from August 2020 to May 2021 is 4,980kWh. “From Grid” on the Consumption view for August 2021 to May 2022 is 3,575kWh, which is about 30% less, but “From Grid” on the System Overview is 4,754kWh, which is only about 5% less. So our loads pulled about 30% less from the grid than the same time the year before, but our system as a whole didn’t.
Now let’s break our ridiculous September-based year down further into months, to see if we can see more detail. I’ve highlighted some interesting periods in bold.
Month
Grid In
Solar In
Total In
Loads
Export
Sep 21 (part)
153
101
254
213
6
Oct 21
636
629
1,265
988
55
Nov 21
430
747
1,177
866
97
Dec 21
232
956
1,188
767
176
Jan 22
652
450
1,102
822
74
Feb 22
470
430
900
638
83
Mar 22
498
568
1,066
813
64
Apr 22
609
377
986
775
27
May 22
910
238
1,148
953
3
Jun 22
1,114
161
1,275
1073
2
Jul 22
1,163
223
1,386
1118
11
Aug 22
910
375
1,285
966
64
Sep 22 (part)
754
385
1,139
857
92
Total
8,531
5,640
14,171
10,849
754
December is great. We generated about 25% more power than our loads use (956/767=1.25), and our grid input was only about 30% of the total of our loads (232/767=0.30).
January and February show the effects of missing three weeks of potential generation. I mean, just look at December through February 2021-2022 versus the previous three summers.
PV Generation December through January 2018-2022
2018-2019
2019-2020
2020-2021
2021-2022
December
919
882
767
956
January
936
797
818
450
February
699
656
711
430
June and July are terrible. They’re our highest load months, with the lowest solar generation and we pulled 3-4% more power from the grid than our loads actually consumed. I’m going to attribute the latter largely to grid charging the battery.
If I dig a couple of interesting figures out for June and July I see “To Battery” on the Solar view shows 205kWh, and “From Battery” on the Consumption view shows 558kWh. Total consumption in that period was 2,191kWh, with the total “From Grid” reported in System Overview of 2,277kWh. Let’s mess with that a bit.
Bearing in mind the efficiency numbers mentioned earlier, if 205kWh went to the battery from PV, that means no more than 154kWh of what we got out of the battery was from PV generation (remember: real world DC-DC stack efficiency of about 75%). The remaining 404kWh out of the battery is power that went into it from the grid. And that means at least 538kWh in (404/0.75). Note that total from grid for these two months was 86kWh more than the 2,191kWh used by our loads. If I hadn’t been keeping the battery topped up from the grid, I’d’ve saved at least 134kWh of grid power, which would have brought our grid input figure back down below our consumption figure. Note also that this number will actually be higher in reality because I haven’t factored in AC/DC conversion losses from the Multis.
Now let’s look at some costs. When I started trying to compare the new system to the previous system, I went in thinking to look at in in terms of total power input to the system, total consumption by loads, and total power exported. There’s one piece missing there, so let’s add another couple of columns to an earlier table:
Year
Grid In
Solar In
Total In
Loads
Export
Total Out
what?
2021-2022
8,531
5,640
14,171
10,849
754
11,603
2,568
The total usable output of the system was 11,603kWh for 14,171kWh input. The difference between these two figures – 2,568kWh, or about 18% – went somewhere else. Per my earlier experiment, 5% is power that went to actually operate the system components, including the battery. That means about 13% of the power input to the system over the course of the year must have gone to some combination of charge/discharge and AC/DC conversion (in)efficiencies. We can consider this the energy cost of the system. To have the ability to time-shift expensive peak grid electricity, and to run the house without the grid if the sun is out, or from the battery when it has charge, costs us 18% of the total available energy input.
Finally, speaking of expensive grid electricity, let’s look at how much we paid Aurora Energy over the past four years for our power. The bills are broken out into different tariffs, for which you’re charged different amounts per kilowatt hour and then there’s an additional daily supply charge, and also credits for power exported. We can simplify that by just taking the total dollar value of all the power bills and dividing that by the total power drawn from the grid to arrive at an effective cost per kilowatt hour for the entire year. Here it is:
Year
From Grid
Total Bill
Cost/kWh
2018-2019
9,031
$2,278.33
$0.25
2019-2020
9,324
$2,384.79
$0.26
2020-2021
7,582
$1,921.77
$0.25
2021-2022
8,531
$1,731.40
$0.20
So, the combination of the battery plus the switch from Flat Rate to Peak & Off-Peak billing has reduced the cost of our grid power by about 20%. I call that a win.
Going forwards it will be interesting to see how the next twelve months go, and, in particular, what we can do to reduce our power consumption. A significant portion of our power is used by a bunch of always-on computer equipment. Some of that I need for my work, and some of that provides internet access, file storage and email for us personally. Altogether, according to the UPSes, this kit pulls 200-250 watts continuously, but will pull more than that during the day when it’s being used interactively. If we call it 250W continuous, that’s a minimum of 6kWh/day, which is 2,190kWh/year, or about 20% of the 2021-2022 consumption. Some of that equipment should be replaced with newer, more power efficient kit. Some of it could possibly even be turned off or put into standby mode some of the time.
We still need to get a heat pump to replace the 2400W panel heater in our bedroom. That should save a huge amount of power in winter. We’re also slowly working our way through the house installing excellent double glazed windows from Elite Double Glazing, which will save on power for heating and cooling year round.
And of course, we still need to get that second ZCell.
What is HCX? VMware HCX is an application mobility platform designed for simplifying application migration, workload rebalancing and business continuity across datacenters and clouds. VMware HCX was formerly known as Hybrid Cloud Extension and NSX Hybrid Connect.
GCVE HCX GCVE deploys the Enterprise version of HCX as part of the cost of the solution.
HCX Enterprise has the following benefits:
Hybrid Interconnect WAN Optimisation Bulk Migration, Live Migration and HCX Replication Assisted vMotion Cloud to cloud migration Disaster Protection KVM & Hyper-V to vSphere migrations Traffic Engineering Mobility Groups Mobility Optimised Networking Changeover scheduling Definitions Cold Migration
We have seen a lot of Google Cloud VMware Engine over the last few months and for the entire time we have used click-ops to provision new infrastructure, networks and VM’s. Now we are going to the next level and we will be using Terraform to manage our infrastructure as code so that it is version controlled and predictable.
Installing Terraform The first part of getting this working is installing Terraform on your local machine.
Picking up where we left off last month, let’s dive into disaster recovery and how to use Site Recovery Manager and Google Backup & Protect to DR into and within the cloud with GCVE.
But before we do, a quick advertisement:
If you are in Brisbane, Australia, I suggest coming to the awesome Google Infrastructure Group (GIG) which focuses on GCVE where on 04 July 2022 I will be presenting on Terraform in GCVE.
Let’s pick up where we left off from last months article and start setting up some of the features of GCVE, starting with Advanced Autoscaling.
What is Advanced Auto-Scaling? Advanced Autoscaling automatically expands or shrinks a private cloud based on CPU, memory and storage utilisation metrics.
GCVE monitors the cluster based on the metrics defined in the autoscale policy and decides to add or remove nodes automatically. Remember: GCVE is physical Dell Poweredge servers, not a container/VM running in Docker or on a hypervisor like VMware.
We’ve done this a number of times over the last decade, from OSDC to LCA. The idea is to provide a free psychologist or counsellor at an in-person conference. Attendees can do an anonymous booking by taking a stickynote (with the timeslot) from a signup sheet, and thus get a free appointment.
Many people find it difficult taking the first (very important) step towards getting professional help, and we’ve received good feedback that this approach indeed assists.
So far we’ve always focused on open source conferences. Now we’re moving into information security! First BrisSEC 2022 (Friday 29 April at the Hilton in Brisbane, QLD) and then AusCERT 2022 (10-13 May at the Star Hotel, Gold Coast QLD). The awesome and geek friendly Dr Carla Rogers will be at both events.
How does this get funded? Well, we’ve crowdfunded some, nudged sponsors, most mostly it gets picked up by the conference organisers (aka indirectly by the sponsors, mostly).
If you’re a conference organiser, or would like a particular upcoming conference to offer this service, do drop us a line and we’re happy to chase it up for you and help the organisers to make it happen. We know how to run that now.
In-person is best. But for virtual conferences, sure contact us as well.
The hack day didn’t go as well as I hoped, but didn’t go too badly. There was smaller attendance than hoped and the discussion was mostly about things other than FLOSS. But everyone who attended had fun and learned interesting things so generally I think it counts as a success. There was discussion on topics including military hardware, viruses (particularly Covid), rocketry, and literature. During the discussion one error in a Wikipedia page was discussed and hopefully we can get that fixed.
I think that everyone who attended will be interested in more such meetings. Overall I think this is a reasonable start to the Hack Day meetings, when I previously ran such meetings they often ended up being more social events than serious hacking events and that’s OK too.
One conclusion that we came to regarding meetings is that they should always be well announced in email and that the iCal file isn’t useful for everyone. Discussion continues on the best methods of announcing meetings but I anticipate that better email will get more attendance.
What is GCVE? Google Cloud VMware Engine, or GCVE, is a fully managed VMware hypervisor and associated management and networking components, (vSphere, NSX-T, vSAN and HCX) built on top of Google’s highly performant and scalable infrastructure with fully redundant and dedicated 100Gbps networking that provides 99.99% availability.
The solution is integrated into Google Cloud Platform, so businesses benefit from having full access to GCP services, native VPC networking, Cloud VPN or Interconnect as well as all the normal security features you expect from GCP.
The March 2022 meeting went reasonably well. Everyone seemed to have fun and learn useful things about computers. After 2 hours my Internet connection dropped out which stopped the people who were using VMs from doing the tutorial. Fortunately most people seemed ready for a break so we ended the meeting. The early and abrupt ending of the meeting was a disappointment but it wasn’t too bad, the meeting would probably only have gone for another half hour otherwise.
The BigBlueButton system was shown to be effective for training when one person got confused with the Debian package configuration options for Postfix and they were able to share the window with everyone else to get advice. I was also confused by that stage.
Future Meetings
The main feature of the meeting was training in setting up a mailserver with Postfix, here are the lecture notes for it [1]. The consensus at the end of the meeting was that people wanted more of that for the April meeting. So for the April meeting I will add to the Postfix Training to include SpamAssassin, SPF, DKIM, and DMARC. For the start of the next meeting instead of providing bare Debian installations for the VMs I’ll provide a basic Postfix/Dovecot setup so people can get straight into SpamAssassin etc.
For the May meeting training on SE Linux was requested.
Social Media
Towards the end of the meeting we discussed Matrix and federated social media. LUV has a Matrix server and I can give accounts to anyone who’s involved in FOSS in the Australia and New Zealand area. For Mastodon the NZOSS Mastodon server [2] seems like a good option. I have an account there to try Mastodon, my Mastodon address is @etbe@mastodon.nzoss.nz .
We are going to make Matrix a primary communication method for the Flounder group, the room is #flounder:luv.asn.au . My Matrix address is @etbe:luv.asn.au .
We also have a new URL for the blog and events. See the right sidebar for the link to the iCal file which can be connected to Google Calendar and most online calendaring systems.
We just had the first Flounder meeting which went well. Had some interesting discussion of storage technology, I learnt a few new things. Some people did the ZFS training and BTRFS training and we had lots of interesting discussion.
Andrew Pam gave a summary of new things in Linux and talked about the sites lwn.net, gamingonlinux.com, and cnx-software.com that he uses to find Linux news. One thing he talked about is the latest developments with SteamDeck which is driving Linux support in Steam games. The site protondb.com tracks Linux support in Steam games.
We had some discussion of BPF, for an introduction to that technology see the BPF lecture from LCA 2022.
Next Meeting
The next meeting (Saturday 5th of March 1PM Melbourne time) will focus on running your own mail server which is always of interest to people who are interested in system administration and which is probably of more interest than usual because of Google forcing companies with “a legacy G Suite subscription” to transition to a more expensive “Business family” offering.
I “recently” wrote about obtaining a new (to me, actually quite old) computer over in The Apple Power Macintosh 7200/120 PC Compatible (Part 1). This post is a bit of a detour, but may help others understand why some images they download from the internet don’t work.
Disk partitioning is (of course) a way to divide up a single disk into multiple volumes (partitions) for different uses. While the idea is similar, computer platforms over the ages have done this in a variety of different ways, with varying formats on disk, and varying limitations. The ones that you’re most likely to be familiar with are the MBR partitioning scheme (from the IBM PC), and the GPT partitioning scheme (common for UEFI systems such as the modern PC and Mac). One you’re less likely to be familiar with is the Apple Partition Map scheme.
The way all IBM PCs and compatibles worked from the introduction of MS-DOS 2.0 in 1983 until some time after 2005 was the Master Boot Record partitioning scheme. It was outrageously simple: of the first 512 byte sector of a disk, the first 446 bytes was for the bootstrapping code (the “boot sector”), the last 2 bytes were for the magic two bytes telling the BIOS this disk was bootable, and the other 64 bytes were four entries of 16 bytes, each describing a disk partition. The Wikipedia page is a good overview of what it all looks like. Since “four partitions should be enough for anybody” wasn’t going to last, DOS 3.2 introduced “extended partitions” which was just using one of those 4 partitions as another similar data structure that could point to more partitions.
In the 1980s (similar to today), the Macintosh was, of course, different. The Apple Partition Map is significantly more flexible than the MBR on PCs. For a start, you could have more than four partitions! You could actually have a lot more than four partitions, as the Apple Partition Map is a single 512-byte sector for each partition, and the partition map is itself a partition. Instead of being block 0 (like the MBR is), it actually starts at block 1, and is contiguous (The Driver Descriptor Record is what’s at block 0). So, once created, it’s hard to extend. Typically it’d be created as 64×512-byte entries, for 32kb… which turns out is actually about enough for anyone.
The Inside Macintosh reference on the SCSI Manager goes through more detail as to these structures. If you’re wondering what language all the coding examples are in, it’s Pascal – which was fairly popular for writing Macintosh applications in back in the day.
But the actual partition map isn’t the “interesting” part of all this (and yes, the quotation marks are significant here), because Macs are pretty darn finicky about what disks to boot off, which gets to be interesting if you’re trying to find a CD-ROM image on the internet from which to boot, and then use to install an Operating System from.
I never programmed a 1980s Macintosh actually in the 1980s. It was sometime in the early 1990s that I first experienced Microsoft Basic for the Macintosh. I’d previously (unknowingly at the time as it was branded Commodore) experienced Microsoft BASIC on the Commodore 16, Commodore 64, and even the Apple ][, but the Macintosh version was something else. It let you do some pretty neat things such as construct a GUI with largely the same amount of effort as it took to construct a Text based UI on the micros I was familiar with.
Okay, to be fair, I’d also dabbled in Microsoft QBasic that came bundled with MS-DOS of the era, which let you do a whole bunch of graphics – so you could theoretically construct a GUI with it. Something I did attempt to do. Programming on the Mac was so much easier to construct a GUI.
Of course, Microsoft Basic wasn’t the preferred way to program on the Macintosh. At that time it was largely Pascal, with C being something that also existed – but you were going to see Pascal in Inside Macintosh. It was probably somewhat fortuitous that I’d poked at Pascal a bit as something alternate to look at in the high school computing classes. I can only remember using TurboPascal on DOS systems and never actually writing Pascal on the Macintosh.
By the middle part of the 1990s though, I was firmly incompetently writing C on the Mac. No doubt the quality of my code increased after I’d done some university courses actually covering the language rather than the only practical way I had to attempt to write anything useful being looking at Inside Macintosh examples in Pascal and “C for Dummies” which was very not-Macintosh. Writing C on UNIX/Linux was a lot easier – everything was made for it, including Actual Documentation!
Anyway, in the early 2000s I ran MacOS X for a bit on my white iBook G3, and did a (very) small amount of any GUI / Project Builder (the precursor to Xcode) related development – instead largely focusing on command line / X11 things. The latest coolness being to use Objective-C to program applications (unless you were bringing over your Classic MacOS Carbon based application, then you could still write C). Enter some (incompetent) Objective-C coding!
Then Apple went to x86, so the hardware ceased being interesting, and I had no reason to poke at it even as a side effect of having hardware that could run the software stack. Enter a long-ass time of Debian, Ubuntu, and Fedora on laptops.
Come 2022 though, and (for reasons I should really write up), I’m poking at a Mac again and it’s now Swift as the preferred way to write apps. So, I’m (incompetently) hacking away at Swift code. I have to admit, it’s pretty nice. I’ve managed to be somewhat productive in a relative short amount of time, and all the affordances in the language gear towards the kind of safety that is a PITA when coding in C.
So this is my WIP utility to be able to import photos from a Shotwell database into the macOS Photos app:
There’s a lot of rough edges and unknowns left, including how to actually do the import (it looks like there’s going to be Swift code doing AppleScript things as the PhotoKit API is inadequate). But hey, some incompetent hacking in not too much time has a kind-of photo browser thing going on that feels pretty snappy.
Recently I read Michael Snoyman’s post on combining Axum, Hyper, Tonic and Tower. While his solution worked, it irked me – it seemed like there should be a much tighter solution possible.
I can deep dive into the code in a later post perhaps, but I think there are four points of difference. One, since the post was written Axum has started boxing its routes : so the enum dispatch approach taken, which delivers low overheads actually has no benefits today.
Two, while writing out the entire type by hand has some benefits, async code is much more pithy.
Thirdly, the code in the post is entirely generic, except the routing function itself.
And fourth, the outer Service<AddrStream> is an unnecessary layer to abstract over: given the similar constraints – the inner Service must take Request<..>, it is possible to just not use a couple of helpers and instead work directly with Service<Request...>.
So, onto a pithier version.
First, the app server code itself.
use std::{convert::Infallible, net::SocketAddr};
use axum::routing::get;
use hyper::{server::conn::AddrStream, service::make_service_fn};
use hyper::{Body, Request};
use tonic::async_trait;
use demo::echo_server::{Echo, EchoServer};
use demo::{EchoReply, EchoRequest};
struct MyEcho;
#[async_trait]
impl Echo for MyEcho {
async fn echo(
&self,
request: tonic::Request<EchoRequest>,
) -> Result<tonic::Response<EchoReply>, tonic::Status> {
Ok(tonic::Response::new(EchoReply {
message: format!("Echoing back: {}", request.get_ref().message),
}))
}
}
#[tokio::main]
async fn main() {
let addr = SocketAddr::from(([0, 0, 0, 0], 3000));
let axum_service = axum::Router::new().route("/", get(|| async { "Hello world!" }));
let grpc_service = tonic::transport::Server::builder()
.add_service(EchoServer::new(MyEcho))
.into_service();
let both_service =
demo_router::Router::new(axum_service, grpc_service, |req: &Request<Body>| {
Ok::<bool, Infallible>(
req.headers().get("content-type").map(|x| x.as_bytes())
== Some(b"application/grpc"),
)
});
let make_service = make_service_fn(move |_conn: &AddrStream| {
let both_service = both_service.clone();
async { Ok::<_, Infallible>(both_service) }
});
let server = hyper::Server::bind(&addr).serve(make_service);
if let Err(e) = server.await {
eprintln!("server error: {}", e);
}
}
Note the Router: it takes the two services and Fn to determine which to use on any given request. Then we just drop that composed service into make_service_fn and we’re done.
Next up we have the Router implementation. This is generic across any two Service<Request<...>> types as long as they are both Into<Bytes> for their Data, and Into<Box<dyn Error>> for errors.
Interesting things here – I use boxed_unsync to abstract over the body concrete type, and I implement the future using async code rather than as a separate struct. It becomes much smaller even after a few bits of extra type constraining.
One thing that flummoxed me for a little was the need to capture the future for the underlying response outside of the async block. Failing to do so provokes a 'static requirement which was tricky to debug. Fortunately there is a bug on making this easier to diagnose in rustc already. The underlying problem is that if you create the async block, and then dereference self, the type for impl of .first has to live an arbitrary time. Whereas by capturing the future immediately, only the impl of the future has to live an arbitrary time, and that doesn’t then require changing the signature of the function.
This is almost worth turning into a crate – I couldn’t see an existing one when I looked, though it does end up rather small – < 100 lines. What do you all think?
The first meeting will start at 1PM Australian Eastern time (Melbourne/Sydney) which is +1100 on Saturday the 5th of February.
I will start the video chat an hour early in case someone makes a timezone mistake and gets there an hour before it starts. If anyone else joins early we will have random chat until the start time (deliberately avoiding topics worthy of the main meeting). The link http://b.coker.com.au will redirect to the meeting URL on the day.
The first scheduled talk is a summary and discussion of free software related news. Anyone who knows of something new that excites them is welcome to speak about it.
The main event is discussion of storage technology and hands-on training on BTRFS and ZFS for those who are interested. Here are the ZFS training notes and here are the BTRFS training notes. Feel free to do the training exercises on your own VM before the meeting if you wish.
Then discussion of the future of the group and the use of FOSS social media. While social media is never going to be compulsory some people will want to use it to communicate and we could run some servers for software that is considered good (lots of server capacity is available).
Finally we have to plan future meetings and decide on which communication methods are desired.
The BBB instance to be used for the video conference is sponsored by NZOSS and Catalyst Cloud.
The main aim is to provide educational benefits to free software users via an online meeting that can’t be obtained by watching YouTube videos etc in a scope that is larger than one country. When the pandemic ends we will keep running this as there are benefits to be obtained from a meeting of a wide geographic scope that can’t be obtained by meetings in a single city. People from other countries are welcome to attend but they aren’t the focus of the meeting.
Until we get a better DNS name the address http://b.coker.com.au will redirect to the BBB instance used for online meetings (the meeting address isn’t yet setup so it redirects to the blog). The aim is that there will always be a short URL for the meeting so anyone who has one device lose contact can quickly type the URL into their backup device.
The first meeting will be on the 5th of Feb 2022 at 1PM Melbourne time +1100. When we get a proper domain I’ll publish a URL for an iCal file with entries for all meetings. I will also find some suitable way for meeting times to be localised (I’m sure there’s a WordPress plugin for that).
For the hands-on part of the meetings there will be virtual machine images you can download to run on your own system (tested with KVM, should work with other VM systems) and the possibility of logging in to a running VM. The demonstration VMs will have public IPv6 addresses and will also be available through different ports on a single IPv4 address, having IPv6 on your workstation will be convenient for you but you can survive without it.
Linux Australia has a list of LUGs in Australia, is there a similar list for NZ? One thing I’d like to see is a list of links for iCal files for all the meetings and also an iCal aggregator that for all iCal feeds of online meetings. I’ll host it myself if necessary, but it’s probably best to do it via Linux Australia (Linux Australasia?) if possible.
I’m attending the https://linux.conf.au/ conference online this weekend, which is always a good opportunity for some sideline hacking.
I found something boneheaded doing that today.
There have been a few times while inventing the OpenHMD Rift driver where I’ve noticed something strange and followed the thread until it made sense. Sometimes that leads to improvements in the driver, sometimes not.
In this case, I wanted to generate a graph of how long the computer vision processing takes – from the moment each camera frame is captured until poses are generated for each device.
To do that, I have a some logging branches that output JSON events to log files and I write scripts to process those. I used that data and produced:
Two things caught my eye in this graph. The first is the way the baseline latency (pink lines) increases from ~20ms to ~58ms. The 2nd is the quantisation effect, where pose latencies are clearly moving in discrete steps.
Neither of those should be happening.
Camera frames are being captured from the CV1 sensors every 19.2ms, and it takes that 17-18ms for them to be delivered across the USB. Depending on how many IR sources the cameras can see, figuring out the device poses can take a different amount of time, but the baseline should always hover around 17-18ms because the fast “device tracking locked” case take as little as 1ms.
Did you see me mention 19.2ms as the interframe period? Guess what the spacing on those quantisation levels are in the graph? I recognised it as implying that something in the processing is tied to frame timing when it should not be.
OpenHMD Rift CV1 tracking timing
This 2nd graph helped me pinpoint what exactly was going on. This graph is cut from the part of the session where the latency has jumped up. What it shows is a ~1 frame delay between when the frame is received (frame-arrival-finish-local-ts) before the initial analysis even starts!
That could imply that the analysis thread is just busy processing the previous frame and doesn’t get start working on the new one yet – but the graph says that fast analysis is typically done in 1-10ms at most. It should rarely be busy when the next frame arrives.
This is where I found the bone headed code – a rookie mistake I wrote when putting in place the image analysis threads early on in the driver development and never noticed.
There are 3 threads involved:
USB service thread, reading video frame packets and assembling pixels in framebuffers
Fast analysis thread, that checks tracking lock is still acquired
Long analysis thread, which does brute-force pose searching to reacquire / match unknown IR sources to device LEDs
These 3 threads communicate using frame worker queues passing frames between each other. Each analysis thread does this pseudocode:
while driver_running:
Pop a frame from the queue
Process the frame
Sleep for new frame notification
The problem is in the 3rd line. If the driver is ever still processing the frame in line 2 when a new frame arrives – say because the computer got really busy – the thread sleeps anyway and won’t wake up until the next frame arrives. At that point, there’ll be 2 frames in the queue, but it only still processes one – so the analysis gains a 1 frame latency from that point on. If it happens a second time, it gets later by another frame! Any further and it starts reclaiming frames from the queues to keep the video capture thread fed – but it only reclaims one frame at a time, so the latency remains!
The fix is simple:
while driver_running:
Pop a frame
Process the frame
if queue_is_empty():
sleep for new frame notification
Doing that for both the fast and long analysis threads changed the profile of the pose latency graph completely.
Pose latency and inter-pose spacing after fix
This is a massive win! To be clear, this has been causing problems in the driver for at least 18 months but was never obvious from the logs alone. A single good graph is worth a thousand logs.
What does this mean in practice?
The way the fusion filter I’ve built works, in between pose updates from the cameras, the position and orientation of each device are predicted / updated using the accelerometer and gyro readings. Particularly for position, using the IMU for prediction drifts fairly quickly. The longer the driver spends ‘coasting’ on the IMU, the less accurate the position tracking is. So, the sooner the driver can get a correction from the camera to the fusion filter the less drift we’ll get – especially under fast motion. Particularly for the hand controllers that get waved around.
Before: Left Controller pose delays by sensorAfter: Left Controller pose delays by sensor
Poses are now being updated up to 40ms earlier and the baseline is consistent with the USB transfer delay.
You can also visibly see the effect of the JPEG decoding support I added over Christmas. The ‘red’ camera is directly connected to USB3, while the ‘khaki’ camera is feeding JPEG frames over USB2 that then need to be decoded, adding a few ms delay.
The latency reduction is nicely visible in the pose graphs, where the ‘drop shadow’ effect of pose updates tailing fusion predictions largely disappears and there are fewer large gaps in the pose observations when long analysis happens (visible as straight lines jumping from point to point in the trace):
Before: Left Controller posesAfter: Left Controller poses
Yes, the blog is still on. January 2004 I moved to WordPress, and it is still here January 2022. I didn’t write much last year (neither here, not experimenting with the Hey blog). I didn’t post anything to Instagram last year either from what I can tell, just a lot of stories.
August 16 2021, I realised I was 1,000 days till May 12 2024, which is when I become 40. As of today, that leads 850 days. Did I squander the last 150 days? I’m back to writing almost daily in the Hobonichi Techo (I think last year and the year before were mostly washouts; I barely scribbled anything offline).
I got a new Apple Watch Series 7 yesterday. I can say I used the Series 4 well (79% battery life), purchased in the UK when I broke my Series 0 in Edinburgh airport.
TripIt stats for last year claimed 95 days on the road. This is of course, a massive joke, but I’m glad I did get to visit London, Lisbon, New York, San Francisco, Los Angeles without issue. I spent a lot of time in Kuantan, a bunch of Langkawi trips, and also, I stayed for many months at the Grand Hyatt Kuala Lumpur during the May lockdowns (I practically stayed there all lockdown).
With 850 days to go till I’m 40, I have plenty I would like to achieve. I think I’ll write a lot more here. And elsewhere. Get back into the habit of doing. And publishing by learning and doing. No fear. Not that I wasn’t doing, but its time to be prolific with what’s been going on.
Once again time has passed, and another update on Oculus Rift support feels due! As always, it feels like I’ve been busy with work and not found enough time for Rift CV1 hacking. Nevertheless, looking back over the history since I last wrote, there’s quite a lot to tell!
In general, the controller tracking is now really good most of the time. Like, wildly-swing-your-arms-and-not-lose-track levels (most of the time). The problems I’m hunting now are intermittent and hard to identify in the moment while using the headset – hence my enthusiasm over the last updates for implementing stream recording and a simulation setup. I’ll get back to that.
Outlier Detection
Since I last wrote, the tracking improvements have mostly come from identifying and rejecting incorrect measurements. That is, if I have 2 sensors active and 1 sensor says the left controller is in one place, but the 2nd sensor says it’s somewhere else, we’ll reject one of those – choosing the pose that best matches what we already know about the controller. The last known position, the gravity direction the IMU is detecting, and the last known orientation. The tracker will now also reject observations for a time if (for example) the reported orientation is outside the range we expect. The IMU gyroscope can track the orientation of a device for quite a while, so can be relied on to identify strong pose priors once we’ve integrated a few camera observations to get the yaw correct.
It works really well, but I think improving this area is still where most future refinements will come. That and avoiding incorrect pose extractions in the first place.
Plot of headset tracking – orientation and position
The above plot is a sample of headset tracking, showing the extracted poses from the computer vision vs the pose priors / tracking from the Kalman filter. As you can see, there are excursions in both position and orientation detected from the video, but these are largely ignored by the filter, producing a steadier result.
Left Touch controller tracking – orientation and position
This plot shows the left controller being tracked during a Beat Saber session. The controller tracking plot is quite different, because controllers move a lot more than the headset, and have fewer LEDs to track against. There are larger gaps here in the timeline while the vision re-acquires the device – and in those gaps you can see the Kalman filter interpolating using IMU input only (sometimes well, sometimes less so).
Improved Pose Priors
Another nice thing I did is changes in the way the search for a tracked device is made in a video frame. Before starting looking for a particular device it always now gets the latest estimate of the previous device position from the fusion filter. Previously, it would use the estimate of the device pose as it was when the camera exposure happened – but between then and the moment we start analysis more IMU observations and other camera observations might arrive and be integrated into the filter, which will have updated the estimate of where the device was in the frame.
This is the bit where I think the Kalman filter is particularly clever: Estimates of the device position at an earlier or later exposure can improve and refine the filter’s estimate of where the device was when the camera captured the frame we’re currently analysing! So clever. That mechanism (lagged state tracking) is what allows the filter to integrate past tracking observations once the analysis is done – so even if the video frame search take 150ms (for example), it will correct the filter’s estimate of where the device was 150ms in the past, which ripples through and corrects the estimate of where the device is now.
LED visibility model
To improve the identification of devices better, I measured the actual angle from which LEDs are visible (about 75 degrees off axis) and measured the size. The pose matching now has a better idea of which LEDs should be visible for a proposed orientation and what pixel size we expect them to have at a particular distance.
Better Smoothing
I fixed a bug in the output pose smoothing filter where it would glitch as you turned completely around and crossed the point where the angle jumps from +pi to -pi or vice versa.
Improved Display Distortion Correction
I got a wide-angle hi-res webcam and took photos of a checkerboard pattern through the lens of my headset, then used OpenCV and panotools to calculate new distortion and chromatic aberration parameters for the display. For me, this has greatly improved. I’m waiting to hear if that’s true for everyone, or if I’ve just fixed it for my headset.
Persistent Config Cache
Config blocks! A long time ago, I prototyped code to create a persistent OpenHMD configuration file store in ~/.config/openhmd. The rift-kalman-filter branch now uses that to store the configuration blocks that it reads from the controllers. The first time a controller is seen, it will load the JSON calibration block as before, but it will now store it in that directory – removing a multiple second radio read process on every subsequent startup.
Persistent Room Configuration
To go along with that, I have an experimental rift-room-config branch that creates a rift-room-config.json file and stores the camera positions after the first startup. I haven’t pushed that to the rift-kalman-filter branch yet, because I’m a bit worried it’ll cause surprising problems for people. If the initial estimate of the headset pose is wrong, the code will back-project the wrong positions for the cameras, which will get written to the file and cause every subsequent run of OpenHMD to generate bad tracking until the file is removed. The goal is to have a loop that monitors whether the camera positions seem stable based on the tracking reports, and to use averaging and resetting to correct them if not – or at least to warn the user that they should re-run some (non-existent) setup utility.
Video Capture + Processing
The final big ticket item was a rewrite of how the USB video frame capture thread collects pixels and passes them to the analysis threads. This now does less work in the USB thread, so misses fewer frames, and also I made it so that every frame is now searched for LEDs and blob identities tracked with motion vectors, even when no further analysis will be done on that frame. That means that when we’re running late, it better preserves LED blob identities until the analysis threads can catch up – increasing the chances of having known LEDs to directly find device positions and avoid searching. This rewrite also opened up a path to easily support JPEG decode – which is needed to support Rift Sensors connected on USB 2.0 ports.
Session Simulator
I mentioned the recording simulator continues to progress. Since the tracking problems are now getting really tricky to figure out, this tool is becoming increasingly important. So far, I have code in OpenHMD to record all video and tracking data to a .mkv file. Then, there’s a simulator tool that loads those recordings. Currently it is capable of extracting the data back out of the recording, parsing the JSON and decoding the video, and presenting it to a partially implemented simulator that then runs the same blob analysis and tracking OpenHMD does. The end goal is a Godot based visualiser for this simulation, and to be able to step back and forth through time examining what happened at critical moments so I can improve the tracking for those situations.
To make recordings, there’s the rift-debug-gstreamer-record branch of OpenHMD. If you have GStreamer and the right plugins (gst-plugins-good) installed, and you set env vars like this, each run of OpenHMD will generate a recording in the target directory (make sure the target dir exists):
The next things that are calling to me are to improve the room configuration estimation and storage as mentioned above – to detect when the poses a camera is reporting don’t make sense because it’s been bumped or moved.
I’d also like to add back in tracking of the LEDS on the back of the headset headband, to support 360 tracking. I disabled those because they cause me trouble – the headband is adjustable relative to the headset, so the LEDs don’t appear where the 3D model says they should be and that causes jitter and pose mismatches. They need special handling.
One last thing I’m finding exciting is a new person taking an interest in Rift S and starting to look at inside-out tracking for that. That’s just happened in the last few days, so not much to report yet – but I’ll be happy to have someone looking at that while I’m still busy over here in CV1 land!
As always, if you have any questions, comments or testing feedback – hit me up at thaytan@noraisin.net or on @thaytan Twitter/IRC.
Thank you to the kind people signed up as Github Sponsors for this project!
For a long time computer manufacturers have tried to differentiate themselves and their products from their competitors with fancy names with odd capitalisation and spelling. But as an author, using these names does a disservice to the reader: how are they to know that DEC is pronounced as if it was written Dec ("deck").
It's time we pushed back, and wrote for our readers, not for corporations.
It's time to use standard English rules for these Corporate Fancy Names. Proper names begin with a capital, unlike "ciscoSystems®" (so bad that Cisco itself moved away from it). Words are separated by spaces, so "Cisco Systems". Abbreviations and acronyms are written in lower case if they are pronounced as a word, in upper case if each letter is pronounced: so "ram" and "IBM®".
So from here on in I'll be using the following:
Face Book. Formerly, "Facebook®".
Junos. Formerly JUNOS®.
ram. Formerly RAM.
Pan OS. Formerly PAN-OS®.
Unix. Formerly UNIX®.
I'd encourage you to try this in your own writing. It does look odd for the first time, but the result is undeniably more readable. If we are not writing to be understood by our audience then we are nothing more than an unpaid member of some corporation's marketing team.
I gave the talk On The Use and Misuse of Decorators as part of PyConline AU 2021, the second in annoyingly long sequence of not-in-person PyCon AU events. Here’s some code samples that you might be interested in:
Simple @property implementation
This shows a demo of @property-style getters. Setters are left as an exercise :)
defdemo_property(f):f.is_a_property=TruereturnfclassHasProperties:def__getattribute__(self,name):ret=super().__getattribute__(name)ifhasattr(ret,"is_a_property"):returnret()else:returnretclassDemo(HasProperties):@demo_propertydefis_a_property(self):return"I'm a property"defis_a_function(self):return"I'm a function"a=Demo()print(a.is_a_function())print(a.is_a_property)
@run (The Scoped Block)
@run is a decorator that will run the body of the decorated function, and then store the result of that function in place of the function’s name. It makes it easier to assign the results of complex statements to a variable, and get the advantages of functions having less leaky scopes than if or loop blocks.
A while ago, I wrote a post about how to build and test my Oculus CV1 tracking code in SteamVR using the SteamVR-OpenHMD driver. I have updated those instructions and moved them to https://noraisin.net/diary/?page_id=1048 – so use those if you’d like to try things out.
The pandemic continues to sap my time for OpenHMD improvements. Since my last post, I have been working on various refinements. The biggest visible improvements are:
Adding velocity and acceleration API to OpenHMD.
Rewriting the pose transformation code that maps from the IMU-centric tracking space to the device pose needed by SteamVR / apps.
Adding velocity and acceleration reporting is needed in VR apps that support throwing things. It means that throwing objects and using gravity-grab to fetch objects works in Half-Life: Alyx, making it playable now.
The rewrite to the pose transformation code fixed problems where the rotation of controller models in VR didn’t match the rotation applied in the real world. Controllers would appear attached to the wrong part of the hand, and rotate around the wrong axis. Movements feel more natural now.
Ongoing work – record and replay
My focus going forward is on fixing glitches that are caused by tracking losses or outliers. Those problems happen when the computer vision code either fails to match what the cameras see to the device LED models, or when it matches incorrectly.
Tracking failure leads to the headset view or controllers ‘flying away’ suddenly. Incorrect matching leads to controllers jumping and jittering to the wrong pose, or swapping hands. Either condition is very annoying.
Unfortunately, as the tracking has improved the remaining problems get harder to understand and there is less low-hanging fruit for improvement. Further, when the computer vision runs at 52Hz, it’s impossible to diagnose the reasons for a glitch in real time.
I’ve built a branch of OpenHMD that uses GStreamer to record the CV1 camera video, plus IMU and tracking logs into a video file.
To go with those recordings, I’ve been working on a replay and simulation tool, that uses the Godot game engine to visualise the tracking session. The goal is to show, frame-by-frame, where OpenHMD thought the cameras, headset and controllers were at each point in the session, and to be able to step back and forth through the recording.
Right now, I’m working on the simulation portion of the replay, that will use the tracking logs to recreate all the poses.
GKE in Production - Part 2 This tutorial is part of a series I am creating on creating, running and managing Kubernetes on GCP the way I do in my day job. In this episode, we are covering how to setup a nginx ingress controller to handle incoming requests.
Note: There may be some things I have skimmed over, if so or you see a glaring hole in my configuration, please drop me a line via the contact page linked at the top of the site.
I’ve been asked more than once what it was like at the beginning of Ubuntu, before it was a company, when an email from someone I’d never heard of came into my mailbox.
We’re coming up on 20 years now since Ubuntu was founded, and I had cause to do some spelunking into IMAP archives recently… while there I took the opportunity to grab the very first email I received.
The Ubuntu long shot succeeded wildly. Of course, we liked to joke about how spammy those emails where: cold-calling a raft of Debian developers with job offers, some of them were closer to phishing attacks :). This very early one – I was the second employee (though I started at 4 days a week to transition my clients gradually) – was less so.
I think its interesting though to note how explicit a gamble this was framed as: a time limited experiment, funded for a year. As the company scaled this very rapidly became a hiring problem and the horizon had to be pushed out to 2 years to get folk to join.
And of course, while we started with arch in earnest, we rapidly hit significant usability problems, some of which were solvable with porcelain and shallow non-architectural changes, and we built initially patches, and then the bazaar VCS project to tackle those. But others were not: for instance, I recall exceeding the 32K hard link limit on ext3 due to a single long history during a VCS conversion. The sum of these challenges led us to create the bzr project, a ground up rethink of our version control needs, architecture, implementation and user-experience. While ultimately git has conquered all, bzr had – still has in fact – extremely loyal advocates, due to its laser sharp focus on usability.
Anyhow, here it is: one of the original no-name-here-yet, aka Ubuntu, introductory emails (with permission from Mark, of course). When I clicked through to the website Mark provided there was a link there to a fantastical website about a space tourist… not what I had expected to be reading in Adelaide during LCA 2004.
From: Mark Shuttleworth <xxx@xxx> To: Robert Collins <xxx@xxx> Date: Thu, 15 Jan 2004, 04:30
Tom Lord gave me your email address, I believe he’s already sent you the email that I sent him so I’m sure you have some background.
In short, I am going to fund some open source development for a year. This is part of a new project that I will be getting off the ground in the coming weeks. I don’t know where it will lead, it’s flying in the face of a stiff breeze but I think at the end of the day it will at least fund a few very good open source developers for a full year to work on the projects they like most.
One of the pieces of the puzzle is high end source code management. I’ll be looking to build an infrastructure that will manage source code for between 100 and 8000 open source projects (yes, there’s a big difference between the two, I don’t know at which end of the spectrum we will be at the end of the year but our infrastructure will have to at least be capable of scaling to the latter within two years) with upwards of 2000 developers, drawing code from a variety of sources, playing with it and spitting it out regularly in nice packages.
Arch and Subversion seem to be the two leading contenders for “next generation open source sccm”. I’d be interested in your thoughts on the two of them, and how they stack up. I’m looking to hire one person who will lead that part of the effort. They’ll work alone from home, and be responsible for two things. First, extending the tool (arch or svn) in ways that help the project. Such extensions will be released under an open source licence, and hopefully embraced by the tools maintainers and included in the mainline code for the tool. And second, they will be responsible for our large-scale implementation of SCCM, using that tool, and building the management scripts and other infrastructure to support such a large, and hopefully highly automated, set of repositories.
Would you be interested in this position? What attributes and experience do you think would make you a great person to have on the team? What would your salary expectation be, as a monthly figure, for a one year contract full time?
I’m currently on your continent, well, just off it. On Lizard Island, up North. Am headed today for Brisbane, then on the 17th to Launceston via Melbourne. If you happen to be on any of those stops, would you be interested in meeting up to discuss it further?
If you’re curious you can find out a bit more about me at www.markshuttleworth.com. This project is much lower key than some of what you’ll find there. It’s a very long shot indeed. But if at worst all that happens is a bunch of open source work gets funded at my expense I’ll feel it was money well spent.
Cheers, Mark
===== — “Good judgement comes from experience, and often experience comes from bad judgement” – Rita Mae Brown
GKE in Production - Part 1 This tutorial is part of a series I am creating on creating, running and managing Kubernetes on GCP the way I do in my day job.
Note: There may be some things I have skimmed over, if so or you see a glaring hole in my configuration, please drop me a line via the contact page linked at the top of the site.
What we will build In this first tutorial, we will be building a standard GKE cluster on Google Cloud Platform and deploying the hello world container to confirm everything is working.
Living in California, I’ve (sadly) grown accustomed to needing to keep track of our local air quality index (AQI) ratings, particularly as we live close to places where large wildfires happen every other year.
Last year, Josh and I bought a PurpleAir outdoor air quality meter, which has been great. We contribute our data to a collection of very local air quality meters, which is important, since the hilly nature of the North Bay means that the nearest government air quality ratings can be significantly different to what we experience here in Petaluma.
I recently went looking to pull my PurpleAir sensor data into my Home Assistant setup. Unfortunately, the PurpleAir API does not return the AQI metric for air quality, only the raw PM2.5/PM5/PM10 numbers. After some searching, I found a nice template sensor solution on the Home Assistant forums, which I’ve modernised by adding the AQI as a sub-sensor, and adding unique ID fields to each useful sensor, so that you can assign them to a location.
You’ll end up with sensors for raw PM2.5, the PM2.5 AQI value, the US EPA air quality category, air pressure, relative humidity and air pressure.
How to use this
First up, visit the PurpleAir Map, find the sensor you care about, click “get this widget�, and then “JSON�. That will give you the URL to set as the resource key in purpleair.yaml.
Adding the configuration
In HomeAssistant, add the following line to your configuration.yaml:
sensor:!includepurpleair.yaml
and then add the following contents to purpleair.yaml
-platform:restname:'PurpleAir'# Substitute in the URL of the sensor you care about. To find the URL, go# to purpleair.com/map, find your sensor, click on it, click on "Get This# Widget" then click on "JSON".resource:https://www.purpleair.com/json?key={KEY_GOES_HERE}&show={SENSOR_ID}# Only query once a minute to avoid rate limits:scan_interval:60# Set this sensor to be the AQI value.## Code translated from JavaScript found at:# https://docs.google.com/document/d/15ijz94dXJ-YAZLi9iZ_RaBwrZ4KtYeCy08goGBwnbCU/edit#value_template:>{{ value_json["results"][0]["Label"] }}unit_of_measurement:""# The value of the sensor can't be longer than 255 characters, but the# attributes can. Store away all the data for use by the templates below.json_attributes:-results-platform:templatesensors:purpleair_aqi:unique_id:'purpleair_SENSORID_aqi_pm25'friendly_name:'PurpleAirPM2.5AQI'value_template:>{% macro calcAQI(Cp, Ih, Il, BPh, BPl) -%}{{ (((Ih - Il)/(BPh - BPl)) * (Cp - BPl) + Il)|round|float }}{%- endmacro %}{% if (states('sensor.purpleair_pm25')|float) > 1000 %}invalid{% elif (states('sensor.purpleair_pm25')|float) > 350.5 %}{{ calcAQI((states('sensor.purpleair_pm25')|float), 500.0, 401.0, 500.0, 350.5) }}{% elif (states('sensor.purpleair_pm25')|float) > 250.5 %}{{ calcAQI((states('sensor.purpleair_pm25')|float), 400.0, 301.0, 350.4, 250.5) }}{% elif (states('sensor.purpleair_pm25')|float) > 150.5 %}{{ calcAQI((states('sensor.purpleair_pm25')|float), 300.0, 201.0, 250.4, 150.5) }}{% elif (states('sensor.purpleair_pm25')|float) > 55.5 %}{{ calcAQI((states('sensor.purpleair_pm25')|float), 200.0, 151.0, 150.4, 55.5) }}{% elif (states('sensor.purpleair_pm25')|float) > 35.5 %}{{ calcAQI((states('sensor.purpleair_pm25')|float), 150.0, 101.0, 55.4, 35.5) }}{% elif (states('sensor.purpleair_pm25')|float) > 12.1 %}{{ calcAQI((states('sensor.purpleair_pm25')|float), 100.0, 51.0, 35.4, 12.1) }}{% elif (states('sensor.purpleair_pm25')|float) >= 0.0 %}{{ calcAQI((states('sensor.purpleair_pm25')|float), 50.0, 0.0, 12.0, 0.0) }}{% else %}invalid{% endif %}unit_of_measurement:"bit"purpleair_description:unique_id:'purpleair_SENSORID_description'friendly_name:'PurpleAirAQIDescription'value_template:>{% if (states('sensor.purpleair_aqi')|float) >= 401.0 %}Hazardous{% elif (states('sensor.purpleair_aqi')|float) >= 301.0 %}Hazardous{% elif (states('sensor.purpleair_aqi')|float) >= 201.0 %}Very Unhealthy{% elif (states('sensor.purpleair_aqi')|float) >= 151.0 %}Unhealthy{% elif (states('sensor.purpleair_aqi')|float) >= 101.0 %}Unhealthy for Sensitive Groups{% elif (states('sensor.purpleair_aqi')|float) >= 51.0 %}Moderate{% elif (states('sensor.purpleair_aqi')|float) >= 0.0 %}Good{% else %}undefined{% endif %}entity_id:sensor.purpleairpurpleair_pm25:unique_id:'purpleair_SENSORID_pm25'friendly_name:'PurpleAirPM2.5'value_template:"{{state_attr('sensor.purpleair','results')[0]['PM2_5Value']}}"unit_of_measurement:"μg/m3"entity_id:sensor.purpleairpurpleair_temp:unique_id:'purpleair_SENSORID_temperature'friendly_name:'PurpleAirTemperature'value_template:"{{state_attr('sensor.purpleair','results')[0]['temp_f']}}"unit_of_measurement:"°F"entity_id:sensor.purpleairpurpleair_humidity:unique_id:'purpleair_SENSORID_humidity'friendly_name:'PurpleAirHumidity'value_template:"{{state_attr('sensor.purpleair','results')[0]['humidity']}}"unit_of_measurement:"%"entity_id:sensor.purpleairpurpleair_pressure:unique_id:'purpleair_SENSORID_pressure'friendly_name:'PurpleAirPressure'value_template:"{{state_attr('sensor.purpleair','results')[0]['pressure']}}"unit_of_measurement:"hPa"entity_id:sensor.purpleair
Quirks
I had difficulty getting the AQI to display as a numeric graph when I didn’t set a unit. I went with bit, and that worked just fine. 🤷�♂�
So, this idea has been brewing for a while now… try and watch all of Doctor Who. All of it. All 38 seasons. Today(ish), we started. First up, from 1963 (first aired not quite when intended due to the Kennedy assassination): An Unearthly Child. The first episode of the first serial.
A lot of iconic things are there from the start: the music, the Police Box, embarrassing moments of not quite remembering what time one is in, and normal humans accidentally finding their way into the TARDIS.
I first saw this way back when a child, where they were repeated on ABC TV in Australia for some anniversary of Doctor Who (I forget which one). Well, I saw all but the first episode as the train home was delayed and stopped outside Caulfield for no reason for ages. Some things never change.
Of course, being a show from the early 1960s, there’s some rougher spots. We’re not about to have the picture of diversity, and there’s going to be casual racism and sexism. What will be interesting is noticing these things today, and contrasting with my memory of them at the time (at least for episodes I’ve seen before), and what I know of the attitudes of the time.
“This year-ometer is not calculating properly” is a very 2020 line though (technically from the second episode).
It’s been a while since my last post about tracking support for the Oculus Rift in February. There’s been big improvements since then – working really well a lot of the time. It’s gone from “If I don’t make any sudden moves, I can finish an easy Beat Saber level” to “You can’t hide from me!” quality.
Equally, there are still enough glitches and corner cases that I think I’ll still be at this a while.
Here’s a video from 3 weeks ago of (not me) playing Beat Saber on Expert+ setting showing just how good things can be now:
Beat Saber – Skunkynator playing Expert+, Mar 16 2021
Strap in. Here’s what I’ve worked on in the last 6 weeks:
Pose Matching improvements
Most of the biggest improvements have come from improving the computer vision algorithm that’s matching the observed LEDs (blobs) in the camera frames to the 3D models of the devices.
I split the brute-force search algorithm into 2 phases. It now does a first pass looking for ‘obvious’ matches. In that pass, it does a shallow graph search of blobs and their nearest few neighbours against LEDs and their nearest neighbours, looking for a match using a “Strong” match metric. A match is considered strong if expected LEDs match observed blobs to within 1.5 pixels.
Coupled with checks on the expected orientation (matching the Gravity vector detected by the IMU) and the pose prior (expected position and orientation are within predicted error bounds) this short-circuit on the search is hit a lot of the time, and often completes within 1 frame duration.
In the remaining tricky cases, where a deeper graph search is required in order to recover the pose, the initial search reduces the number of LEDs and blobs under consideration, speeding up the remaining search.
I also added an LED size model to the mix – for a candidate pose, it tries to work out how large (in pixels) each LED should appear, and use that as a bound on matching blobs to LEDs. This helps reduce mismatches as devices move further from the camera.
LED labelling
When a brute-force search for pose recovery completes, the system now knows the identity of various blobs in the camera image. One way it avoids a search next time is to transfer the labels into future camera observations using optical-flow tracking on the visible blobs.
The problem is that even sped-up the search can still take a few frame-durations to complete. Previously LED labels would be transferred from frame to frame as they arrived, but there’s now a unique ID associated with each blob that allows the labels to be transferred even several frames later once their identity is known.
IMU Gyro scale
One of the problems with reverse engineering is the guesswork around exactly what different values mean. I was looking into why the controller movement felt “swimmy” under fast motions, and one thing I found was that the interpretation of the gyroscope readings from the IMU was incorrect.
The touch controllers report IMU angular velocity readings directly as a 16-bit signed integer. Previously the code would take the reading and divide by 1024 and use the value as radians/second.
From teardowns of the controller, I know the IMU is an Invensense MPU-6500. From the datasheet, the reported value is actually in degrees per second and appears to be configured for the +/- 2000 °/s range. That yields a calculation of Gyro-rad/s = Gyro-°/s * (2000 / 32768) * (?/180) – or a divisor of 938.734.
The 1024 divisor was under-estimating rotation speed by about 10% – close enough to work until you start moving quickly.
Limited interpolation
If we don’t find a device in the camera views, the fusion filter predicts motion using the IMU readings – but that quickly becomes inaccurate. In the worst case, the controllers fly off into the distance. To avoid that, I added a limit of 500ms for ‘coasting’. If we haven’t recovered the device pose by then, the position is frozen in place and only rotation is updated until the cameras find it again.
Exponential filtering
I implemented a 1-Euro exponential smoothing filter on the output poses for each device. This is an idea from the Project Esky driver for Project North Star/Deck-X AR headsets, and almost completely eliminates jitter in the headset view and hand controllers shown to the user. The tradeoff is against introducing lag when the user moves quickly – but there are some tunables in the exponential filter to play with for minimising that. For now I’ve picked some values that seem to work reasonably.
Non-blocking radio
Communications with the touch controllers happens through USB radio command packets sent to the headset. The main use of radio commands in OpenHMD is to read the JSON configuration block for each controller that is programmed in at the factory. The configuration block provides the 3D model of LED positions as well as initial IMU bias values.
Unfortunately, reading the configuration block takes a couple of seconds on startup, and blocks everything while it’s happening. Oculus saw that problem and added a checksum in the controller firmware. You can read the checksum first and if it hasn’t changed use a local cache of the configuration block. Eventually, I’ll implement that caching mechanism for OpenHMD but in the meantime it still reads the configuration blocks on each startup.
As an interim improvement I rewrote the radio communication logic to use a state machine that is checked in the update loop – allowing radio communications to be interleaved without blocking the regularly processing of events. It still interferes a bit, but no longer causes a full multi-second stall as each hand controller turns on.
Haptic feedback
The hand controllers have haptic feedback ‘rumble’ motors that really add to the immersiveness of VR by letting you sense collisions with objects. Until now, OpenHMD hasn’t had any support for applications to trigger haptic events. I spent a bit of time looking at USB packet traces with Philipp Zabel and we figured out the radio commands to turn the rumble motors on and off.
In the Rift CV1, the haptic motors have a mode where you schedule feedback events into a ringbuffer – effectively they operate like a low frequency audio device. However, that mode was removed for the Rift S (and presumably in the Quest devices) – and deprecated for the CV1.
With that in mind, I aimed for implementing the unbuffered mode, with explicit ‘motor on + frequency + amplitude’ and ‘motor off’ commands sent as needed. Thanks to already having rewritten the radio communications to use a state machine, adding haptic commands was fairly easy.
I’d say the biggest problem right now is unexpected tracking loss and incorrect pose extractions when I’m not expecting them. Especially my right controller will suddenly glitch and start jumping around. Looking at a video of the debug feed, it’s not obvious why that’s happening:
To fix cases like those, I plan to add code to log the raw video feed and the IMU information together so that I can replay the video analysis frame-by-frame and investigate glitches systematically. Those recordings will also work as a regression suite to test future changes.
Sensor fusion efficiency
The Kalman filter I have implemented works really nicely – it does the latency compensation, predicts motion and extracts sensor biases all in one place… but it has a big downside of being quite expensive in CPU. The Unscented Kalman Filter CPU cost grows at O(n^3) with the size of the state, and the state in this case is 43 dimensional – 22 base dimensions, and 7 per latency-compensation slot. Running 1000 updates per second for the HMD and 500 for each of the hand controllers adds up quickly.
At some point, I want to find a better / cheaper approach to the problem that still provides low-latency motion predictions for the user while still providing the same benefits around latency compensation and bias extraction.
Lens Distortion
To generate a convincing illusion of objects at a distance in a headset that’s only a few centimetres deep, VR headsets use some interesting optics. The LCD/OLED panels displaying the output get distorted heavily before they hit the users eyes. What the software generates needs to compensate by applying the right inverse distortion to the output video.
Everyone that tests the CV1 notices that the distortion is not quite correct. As you look around, the world warps and shifts annoyingly. Sooner or later that needs fixing. That’s done by taking photos of calibration patterns through the headset lenses and generating a distortion model.
Camera / USB failures
The camera feeds are captured using a custom user-space UVC driver implementation that knows how to set up the special synchronisation settings of the CV1 and DK2 cameras, and then repeatedly schedules isochronous USB packet transfers to receive the video.
Occasionally, some people experience failure to re-schedule those transfers. The kernel rejects them with an out-of-memory error failing to set aside DMA memory (even though it may have been running fine for quite some time). It’s not clear why that happens – but the end result at the moment is that the USB traffic for that camera dies completely and there’ll be no more tracking from that camera until the application is restarted.
Often once it starts happening, it will keep happening until the PC is rebooted and the kernel memory state is reset.
Occluded cases
Tracking generally works well when the cameras get a clear shot of each device, but there are cases like sighting down the barrel of a gun where we expect that the user will line up the controllers in front of one another, and in front of the headset. In that case, even though we probably have a good idea where each device is, it can be hard to figure out which LEDs belong to which device.
If we already have a good tracking lock on the devices, I think it should be possible to keep tracking even down to 1 or 2 LEDs being visible – but the pose assessment code will have to be aware that’s what is happening.
Upstreaming
April 14th marks 2 years since I first branched off OpenHMD master to start working on CV1 tracking. How hard can it be, I thought? I’ll knock this over in a few months.
Since then I’ve accumulated over 300 commits on top of OpenHMD master that eventually all need upstreaming in some way.
One thing people have expressed as a prerequisite for upstreaming is to try and remove the OpenCV dependency. The tracking relies on OpenCV to do camera distortion calculations, and for their PnP implementation. It should be possible to reimplement both of those directly in OpenHMD with a bit of work – possibly using the fast LambdaTwist P3P algorithm that Philipp Zabel wrote, that I’m already using for pose extraction in the brute-force search.
Others
I’ve picked the top issues to highlight here. https://github.com/thaytan/OpenHMD/issues has a list of all the other things that are still on the radar for fixing eventually.
Other Headsets
At some point soon, I plan to put a pin in the CV1 tracking and look at adapting it to more recent inside-out headsets like the Rift S and WMR headsets. I implemented 3DOF support for the Rift S last year, but getting to full positional tracking for that and other inside-out headsets means implementing a SLAM/VIO tracking algorithm to track the headset position.
Once the headset is tracking, the code I’m developing here for CV1 to find and track controllers will hopefully transfer across – the difference with inside-out tracking is that the cameras move around with the headset. Finding the controllers in the actual video feed should work much the same.
Sponsorship
This development happens mostly in my spare time and partly as open source contribution time at work at Centricular. I am accepting funding through Github Sponsorships to help me spend more time on it – I’d really like to keep helping Linux have top-notch support for VR/AR applications. Big thanks to the people that have helped get this far.
Why that particular date? It’s Vincent van Gogh’s birthday (1853), and there is a fairly strong argument that the Dutch painter suffered from bipolar (among other things).
The image on the side is Vincent’s drawing “Worn Out” (from 1882), and it seems to capture the feeling rather well – whether (hypo)manic, depressed, or mixed. It’s exhausting.
Bipolar is complicated, often undiagnosed or misdiagnosed, and when only treated with anti-depressants, it can trigger the (hypo)mania – essentially dragging that person into that state near-permanently.
Have you heard of Bipolar II?
Hypo-mania is the “lesser” form of mania that distinguishes Bipolar I (the classic “manic depressive” syndrome) from Bipolar II. It’s “lesser” only in the sense that rather than someone going so hyper they may think they can fly (Bipolar I is often identified when someone in manic state gets admitted to hospital – good catch!) while with Bipolar II the hypo-mania may actually exhibit as anger. Anger in general, against nothing in particular but potentially everyone and everything around them. Or, if it’s a mixed episode, anger combined with strong negative thoughts. Either way, it does not look like classic mania. It is, however, exhausting and can be very debilitating.
Bipolar II people often present to a doctor while in depressed state, and GPs (not being psychiatrists) may not do a full diagnosis. Note that D.A.S. and similar test sheets are screening tools, they are not diagnostic. A proper diagnosis is more complex than filling in a form some questions (who would have thought!)
Call to action
If you have a diagnosis of depression, only from a GP, and are on medication for this, I would strongly recommend you also get a referral to a psychiatrist to confirm that diagnosis.
Our friends at the awesome Black Dog Institute have excellent information on bipolar, as well as a quick self-test – if that shows some likelihood of bipolar, go get that referral and follow up ASAP.
I will be writing more about the topic in the coming time.
This post documented an older method of building SteamVR-OpenHMD. I moved them to a page here. That version will be kept up to date for any future changes, so go there.
I’ve had a few people ask how to test my OpenHMD development branch of Rift CV1 positional tracking in SteamVR. Here’s what I do:
It is important to configure in release mode, as the kalman filtering code is generally too slow for real-time in debug mode (it has to run 2000 times per second)
Please note – only Rift sensors on USB 3.0 ports will work right now. Supporting cameras on USB 2.0 requires someone implementing JPEG format streaming and decoding.
It can be helpful to test OpenHMD is working by running the simple example. Check that it’s finding camera sensors at startup, and that the position seems to change when you move the headset:
Calibrate your expectations for how well tracking is working right now! Hint: It’s very experimental
Start SteamVR. Hopefully it should detect your headset and the light(s) on your Rift Sensor(s) should power on.
Meson
I prefer the Meson build system here. There’s also a cmake build for SteamVR-OpenHMD you can use instead, but I haven’t tested it in a while and it sometimes breaks as I work on my development branch.
I spent some time this weekend implementing a couple of my ideas for improving the way the tracking code in OpenHMD filters and rejects (or accepts) possible poses when trying to match visible LEDs to the 3D models for each device.
In general, the tracking proceeds in several steps (in parallel for each of the 3 devices being tracked):
Do a brute-force search to match LEDs to 3D models, then (if matched)
Assign labels to each LED blob in the video frame saying what LED they are.
Send an update to the fusion filter about the position / orientation of the device
Then, as each video frame arrives:
Use motion flow between video frames to track the movement of each visible LED
Use the IMU + vision fusion filter to predict the position/orientation (pose) of each device, and calculate which LEDs are expected to be visible and where.
Try and match up and refine the poses using the predicted pose prior and labelled LEDs. In the best case, the LEDs are exactly where the fusion predicts they’ll be. More often, the orientation is mostly correct, but the position has drifted and needs correcting. In the worst case, we send the frame back to step 1 and do a brute-force search to reacquire an object.
The goal is to always assign the correct LEDs to the correct device (so you don’t end up with the right controller in your left hand), and to avoid going back to the expensive brute-force search to re-acquire devices as much as possible
What I’ve been working on this week is steps 1 and 3 – initial acquisition of correct poses, and fast validation / refinement of the pose in each video frame, and I’ve implemented two new strategies for that.
Gravity Vector matching
The first new strategy is to reject candidate poses that don’t closely match the known direction of gravity for each device. I had a previous implementation of that idea which turned out to be wrong, so I’ve re-worked it and it helps a lot with device acquisition.
The IMU accelerometer and gyro can usually tell us which way up the device is (roll and pitch) but not which way they are facing (yaw). The measure for ‘known gravity’ comes from the fusion Kalman filter covariance matrix – how certain the filter is about the orientation of the device. If that variance is small this new strategy is used to reject possible poses that don’t have the same idea of gravity (while permitting rotations around the Y axis), with the filter variance as a tolerance.
Partial tracking matches
The 2nd strategy is based around tracking with fewer LED correspondences once a tracking lock is acquired. Initial acquisition of the device pose relies on some heuristics for how many LEDs must match the 3D model. The general heuristic threshold I settled on for now is that 2/3rds of the expected LEDs must be visible to acquire a cold lock.
With the new strategy, if the pose prior has a good idea where the device is and which way it’s facing, it allows matching on far fewer LED correspondences. The idea is to keep tracking a device even down to just a couple of LEDs, and hope that more become visible soon.
While this definitely seems to help, I think the approach can use more work.
Status
With these two new approaches, tracking is improved but still quite erratic. Tracking of the headset itself is quite good now and for me rarely loses tracking lock. The controllers are better, but have a tendency to “fly off my hands” unexpectedly, especially after fast motions.
I have ideas for more tracking heuristics to implement, and I expect a continuous cycle of refinement on the existing strategies and new ones for some time to come.
For now, here’s a video of me playing Beat Saber using tonight’s code. The video shows the debug stream that OpenHMD can generate via Pipewire, showing the camera feed plus overlays of device predictions, LED device assignments and tracked device positions. Red is the headset, Green is the right controller, Blue is the left controller.
Initial tracking is completely wrong – I see some things to fix there. When the controllers go offline due to inactivity, the code keeps trying to match LEDs to them for example, and then there are some things wrong with how it’s relabelling LEDs when they get incorrect assignments.
After that, there are periods of good tracking with random tracking losses on the controllers – those show the problem cases to concentrate on.
These lack of updates are also likely because I’ve been quite caught up with stuff.
Monday I had a steak from Bay Leaf Steakhouse for dinner. It was kind of weird eating it from packs, but then I’m reminded you could do this in economy class. Tuesday I wanted to attempt to go vegetarian and by the time I was done with a workout, the only place was a chap fan shop (Leong Heng) where I had a mixture of Chinese and Indian chap fan. The Indian stall is run by an ex-Hyatt staff member who immediately recognised me! Wednesday, Alice came to visit, so we got to Hanks, got some alcohol, and managed a smorgasbord of food from Pickers/Sate Zul/Lila Wadi. Night ended very late, and on Thursday, visited Hai Tian for their famous salted egg squid and prawns in a coconut shell. Friday was back to being normal, so I grabbed a pizza from Mint Pizza (this time I tried their Aussie variant). Saturday, today, I hit up Rasa Sayang for some matcha latte, but grabbed food from Classic Pilot Cafe, which Faeeza owns! It was the famous salted egg chicken, double portion, half rice.
As for workouts, I did sign up for Mantas but found it pretty hard to do, timezone wise. I did spend a lot of time jogging on the beach (this has been almost a daily affair). Monday I also did 2 MD workouts, Tuesday 1 MD workout, Wednesday half a MD workout, Thursday I did a Ping workout at Pwrhouse (so good!), Friday 1 MD workout, and Saturday an Audrey workout at Pwrhouse and 1 MD workout.
Wednesday I also found out that Rasmus passed away. Frankly, there are no words.
Thursday, my Raspberry Pi 400 arrived. I set it up in under ten minutes, connecting it to the TV here. It “just works”. I made a video, which I should probably figure out how to upload to YouTube after I stitch it together. I have to work on using it a lot more.
COVID-19 cases are through the roof in Malaysia. This weekend we’ve seen two days of case breaking records, with today being 5,728 (yesterday was something close). Nutty. Singapore suspended the reciprocal green lane (RGL) agreement with Malaysia for the next 3 months.
I’ve managed to finish Bridgerton. I like the score. Finding something on Netflix is proving to be more difficult, regardless of having a VPN. Honestly, this is why Cable TV wins… linear programming that you’re just fed.
Stock market wise, I’ve been following the GameStop short squeeze, and even funnier is the Top Glove one, that they’re trying to repeat in Malaysia. Bitcoin seems to be doing “reasonably well” and I have to say, I think people are starting to realise decentralised services have a future. How do we get there?
What an interesting week, I look forward to more productive time. I’m still writing in my Hobonichi Techo, so at least that’s where most personal stuff ends up, I guess?
I hit an important OpenHMD milestone tonight – I completed a Beat Saber level using my Oculus Rift CV1!
I’ve been continuing to work on integrating Kalman filtering into OpenHMD, and on improving the computer vision that matches and tracks device LEDs. While I suspect noone will be completing Expert levels just yet, it’s working well enough that I was able to play through a complete level of Beat Saber. For a long time this has been my mental benchmark for tracking performance, and I’m really happy
Check it out:
I should admit at this point that completing this level took me multiple attempts. The tracking still has quite a tendency to lose track of controllers, or to get them confused and swap hands suddenly.
I have a list of more things to work on. See you at the next update!
What an unplanned day. I woke up in time to do an MD workout, despite feeling a little sore. So maybe I was about 10 minutes late and I missed the first set, but his workouts are so long, and I think there were seven sets anyway. Had a good brunch shortly thereafter.
Did a bit of reading, and then I decided to do a beach boardwalk walk… turns out they were policing the place, and you can’t hit the boardwalk. But the beach is fair game? So I went back to the hotel, dropped off my slippers, and went for a beach jog. Pretty nutty.
Came back to read a little more and figured I might as well do another MD workout. Then I headed out for dinner, trying out a new place — Mint Pizza. Opened 20.12.2020, and they’re empty, and their pizza is actually pretty good. Lamb and BBQ chicken, they did half-and-half.
Twitter was discussing Raspberry Pi’s, and all I could see is a lot of misinformation, which is truly shocking. The irony is that open source has been running the Internet for so long, and progressive web apps have come such a long way…
Learn concepts, not tools.
One ensures lifelong flexibility, the other has potential for obsolescence.
Your knowledge of doing a mail merge will spread from Word, to Pages, to Writer or Docs.
Back in the day when I did OpenOffice.org or Linux training even, we always did say you should learn concepts and not tools. From the time we ran Linux installfests in the late-90s in Sunway Pyramid (back then, yes, Linux was hard, and you had winmodems), but I had forgotten that I even did stuff for school teachers and NGOs back in 2002… I won’t forget PC Gemilang either…
Anyway, I placed an order again for another Raspberry Pi 400. I am certain that most people talk so much crap, without realising that Malaysia isn’t a developed nation and most people can’t afford a Mac let alone a PC. Laptops aren’t cheap. And there are so many other issues…. Saying Windows is still required in 2021 is the nuttiest thing I’ve heard in a long time. Easy to tweet, much harder to think about TCO, and realise where in the journey Malaysia is.
Maybe the best thing was that Malaysian Twitter learned about technology. I doubt many realised the difference between a Pi board vs the 400, but hey, the fact that they talked about tech is still a win (misinformed, but a win).
Today is the first day that in the state of Pahang, we have to encounter what many Malaysians are referring to as the Movement Control Order 2.0 (MCO 2.0). I think everyone finally agrees with the terminology that this is a lockdown now, because I remember back in the day when I was calling it that, I’d definitely offend a handful of journalists.
This is one interesting change for me compared to when I last wrote Life with Rona — Day 56 of being indoors and not even leaving my household, in Kuala Lumpur. I am now not in the state, I am living in a hotel, and I am obviously moving around a little more since we have access to the beach.
KL/Selangor and several other states have already been under the MCO 2.0 since January 13 2021, and while it was supposed to end on January 26, it seems like they’ve extended and harmonised the dates for Peninsular Malaysia to end on February 4 2021. I guess everyone got the “good news” yesterday. The Prime Minister announced some kind of aid last week, but it is still mostly a joke.
Today was the 2nd day I woke up at around 2.30pm because I went to bed at around 8am. First day I had a 23.5 hour uptime, and the today was less brutal, but working from 1-8am with the PST timezone is pretty brutal. Consequently, I barely got too much done, and had one meal, vegetarian, two packs that included rice. I did get to walk by the beach (between Teluk Cempedak and Teluk Cempedak 2), did quite a bit of exercise there and I think even the monkeys are getting hungry… lots of stray cats and monkeys. Starbucks closes at 7pm, and I rocked up at 7.10pm (this was just like yesterday, when I arrived at 9.55pm and was told they wouldn’t grant me a coffee!).
While writing this entry, I did manage to get into a long video call with some friends and I guess it was good catching up with people in various states. It also is what prevented me from publishing this entry!
Day 2
I did wake up reasonable early today because I had pre-ordered room service to arrive at 9am. There is a fixed menu at the hotel for various cuisines (RM48/pax, thankfully gratis for me) and I told them I prefer not having to waste, so just give me what I want which is off menu items anyway. Roti telur double telur (yes, I know it is a roti jantan) with some banjir dhal and sambal and a bit of fruit on the side with two teh tariks. They delivered as requested. I did forget to ask for a jar of honey but that is OK, there is always tomorrow.
I spent most of the day vacillating, and wouldn’t consider it productive by any measure. Just chit chats and napping. It did rain today after a long time, so the day seemed fairly dreary.
When I finally did awaken from my nap, I went for a run on the beach. I did it barefoot. I have no idea if this is how it is supposed to be done, or if you are to run nearer the water or further up above, but I did move around between the two quite often. The beach is still pretty dead, but it is expected since no one is allowed to go unless you’re a hotel guest.
The hotel has closed 3/4 of their villages (blocks) and moved everyone to the village I’m staying in (for long stay guests…). I’m thankful I have a pretty large suite, it is a little over 980sqft, and the ample space, while smaller than my home, is still welcome.
Post beach run, I did a workout with MD via Instagram. It was strength/HIIT based, and I burnt a tonne, because he gave us one of his signature 1.5h classes. It was longer than the 80 minute class he normally charges RM50 for (I still think this is undervaluing his service, but he really does care and does it for the love of seeing his students grow!).
Post-workout I decided to head downtown to find some dinner. Everything at the Teluk Cemepdak block of shops was closed, so they’re not even bothered with doing takeaway. Sg. Lembing steakhouse seemed to have cars parked, Vanggey was empty (Crocodile Rock was open, can’t say if there was a crowd, because the shared parking lot was empty), there was a modest queue at Sate Zul, and further down, Lena was closed, Pickers was open for takeaway but looked pretty closed, Tjantek was open surprisingly, and then I thought I’d give Nusantara a try again, this time for food, but their chef had just gone home at about 8pm. Oops. So I drove to LAN burger, initially ordering just one chicken double special; however they looked like they could use the business so I added on a beef double special. They now accept Boost payments so have joined the e-wallet era. One less place to use cash, which is also why I really like Kuantan. On the drive back, Classic Pilot Cafe was also open and I guess I’ll be heading there too during this lockdown.
Came back to the room to finish both burgers in probably under 15 minutes. While watching the first episode of Bridgerton on Netflix. I’m not sure what really captivates, but I will continue on (I still haven’t finished the first episode). I need to figure out how to use the 2 TVs that I have in this room — HDMI cable? Apple TV? Not normally using a TV, all this is clearly more complex than I care to admit.
I soaked longer than expected, ended up a prune, but I’m sure it will give me good rest!
One thought to leave with:
“Learn to enjoy every minute of your life. Be happy now. Don’t wait for something outside of yourself to make you happy in the future.” — Earl Nightingale
In my experience, the C programming language is still hard to beat, even 50 years after it was first developed (and I feel the same way about UNIX). When it comes to general-purpose utility, low-level systems programming, performance, and portability (even to tiny embedded systems), I would choose C over most modern or fashionable alternatives. In some cases, it is almost the only choice.
Many developers believe that it is difficult to write secure and reliable software in C, due to its free pointers, the lack of enforced memory integrity, and the lack of automatic memory management; however in my opinion it is possible to overcome these risks with discipline and a more secure system of libraries constructed on top of C and libc. Daniel J. Bernstein and Wietse Venema are two developers who have been able to write highly secure, stable, reliable software in C.
My other favourite language is Python. Although Python has numerous desirable features, my favourite is the light-weight syntax: in Python, block structure is indicated by indentation, and braces and semicolons are not required. Apart from the pleasure and relief of reading and writing such light and clear code, which almost appears to be executable pseudo-code, there are many other benefits. In C or JavaScript, if you omit a trailing brace somewhere in the code, or insert an extra brace somewhere, the compiler may tell you that there is a syntax error at the end of the file. These errors can be annoying to track down, and cannot occur in Python. Python not only looks better, the clear syntax helps to avoid errors.
The obvious disadvantage of Python, and other dynamic interpreted languages, is that most programs run extremely slower than C programs. This limits the scope and generality of Python. No AAA or performance-oriented video game engines are programmed in Python. The language is not suitable for low-level systems programming, such as operating system development, device drivers, filesystems, performance-critical networking servers, or real-time systems.
C is a great all-purpose language, but the code is uglier than Python code. Once upon a time, when I was experimenting with the Plan 9 operating system (which is built on C, but lacks Python), I missed Python’s syntax, so I decided to do something about it and write a little preprocessor for C. This converts from a “Pythonesque” indented syntax to regular C with the braces and semicolons. Having forked a little dialect of my own, I continued from there adding other modules and features (which might have been a mistake, but it has been fun and rewarding).
At first I called this translator Brace, because it added in the braces for me. I now call the language CZ. It sounds like “C-easy”. Ease-of-use for developers (DX) is the primary goal. CZ has all of the features of C, and translates cleanly into C, which is then compiled to machine code as normal (using any C compiler; I didn’t write one); and so CZ has the same features and performance as C, but enjoys a more pleasing syntax.
CZ is now self-hosted, in that the translator is written in the language CZ. I confess that originally I wrote most of it in Perl; I’m proficient at Perl, but I consider it to be a fairly ugly language, and overly complicated.
I intend for CZ’s new syntax to be “optional”, ideally a developer will be able to choose to use the normal C syntax when editing CZ, if they prefer it. For this, I need a tool to convert C back to CZ, which I have not fully implemented yet. I am aware that, in addition to traditionalists, some vision-impaired developers prefer to use braces and semicolons, as screen readers might not clearly indicate indentation. A C to CZ translator would of course also be valuable when porting an existing C program to CZ.
CZ has a number of useful features that are not found in standard C, but I did not go so far as C++, which language has been described as “an octopus made by nailing extra legs onto a dog”. I do not consider C to be a dog, at least not in a negative sense; but I think that C++ is not an improvement over plain C. I am creating CZ because I think that it is possible to improve on C, without losing any of its advantages or making it too complex.
One of the most interesting features I added is a simple syntax for fast, light coroutines. I based this on Simon Tatham’s approach to Coroutines in C, which may seem hacky at first glance, but is very efficient and can work very well in practice. I implemented a very fast web server with very clean code using these coroutines. The cost of switching coroutines with this method is little more than the cost of a function call.
CZ has hygienic macros. The regular cpp (C preprocessor) macros are not hygenic and many people consider them hacky and unsafe to use. My CZ macros are safe, and somewhat more powerful than standard C macros. They can be used to neatly add new program control structures. I have plans to further develop the macro system in interesting ways.
I added automatic prototype and header generation, as I do not like having to repeat myself when copying prototypes to separate header files. I added support for the UNIX #! scripting syntax, and for cached executables, which means that CZ can be used like a scripting language without having to use a separate compile or make command, but the programs are only recompiled when something has been changed.
For CZ, I invented a neat approach to portability without conditional compilation directives. Platform-specific library fragments are automatically included from directories having the name of that platform or platform-category. This can work very well in practice, and helps to avoid the nightmare of conditional compilation, feature detection, and Autotools. Using this method, I was able easily to implement portable interfaces to features such as asynchronous IO multiplexing (aka select / poll).
The CZ library includes flexible error handling wrappers, inspired by W. Richard Stevens’ wrappers in his books on Unix Network Programming. If these wrappers are used, there is no need to check return values for error codes, and this makes the code much safer, as an error cannot accidentally be ignored.
CZ has several major faults, which I intend to correct at some point. Some of the syntax is poorly thought out, and I need to revisit it. I developed a fairly rich library to go with the language, including safer data structures, IO, networking, graphics, and sound. There are many nice features, but my CZ library is more prototype than a finished product, there are major omissions, and some features are misconceived or poorly implemented. The misfeatures should be weeded out for the time-being, or moved to an experimental section of the library.
I think that a good software library should come in two parts, the essential low-level APIs with the minimum necessary functionality, and a rich set of high-level convenience functions built on top of the minimal API. I need to clearly separate these two parts in order to avoid polluting the namespaces with all sorts of nonsense!
CZ is lacking a good modern system of symbol namespaces. I can look to Python for a great example. I need to maintain compatibility with C, and avoid ugly symbol encodings. I think I can come up with something that will alleviate the need to type anything like gtk_window_set_default_size, and yet maintain compatibility with the library in question. I want all the power of C, but it should be easy to use, even for children. It should be as easy as BASIC or Processing, a child should be able to write short graphical demos and the like, without stumbling over tricky syntax or obscure compile errors.
Here is an example of a simple CZ program which plots the Mandelbrot set fractal. I think that the program is fairly clear and easy to understand, although there is still some potential to improve and clarify the code.
#!/usr/local/bin/cz --
use b
use ccomplex
Main:
num outside = 16, ox = -0.5, oy = 0, r = 1.5
long i, max_i = 50, rb_i = 30
space()
uint32_t *px = pixel() # CONFIGURE!
num d = 2*r/h, x0 = ox-d*w_2, y0 = oy+d*h_2
for(y, 0, h):
cmplx c = x0 + (y0-d*y)*I
repeat(w):
cmplx w = c
for i=0; i < max_i && cabs(w) < outside; ++i
w = w*w + c
*px++ = i < max_i ? rainbow(i*359 / rb_i % 360) : black
c += d
I wrote a more elaborate variant of this program, which generates images like the one shown below. There are a few tricks used: continuous colouring, rainbow colours, and plotting the logarithm of the iteration count, which makes the plot appear less busy close to the black fractal proper. I sell some T-shirts and other products with these fractal designs online.
An image from the Mandelbrot set, generated by a fairly simple CZ program.
I am interested in graph programming, and have been for three decades since I was a teenager. By graph programming, I mean programming and modelling based on mathematical graphs or diagrams. I avoid the term visual programming, because there is no necessary reason that vision impaired folks could not use a graph programming language; a graph or diagram may be perceived, understood, and manipulated without having to see it.
Mathematics is something that naturally exists, outside time and independent of our universe. We humans discover mathematics, we do not invent or create it. One of my main ideas for graph programming is to represent a mathematical (or software) model in the simplest and most natural way, using relational operators. Elementary mathematics can be reduced to just a few such operators:
+
add, subtract, disjoint union, zero
×
multiply, divide, cartesian product, one
^
power, root, logarithm
◢
sin, cos, sin-1, cos-1, hypot, atan2
δ
differential, integral
a set of minimal relational operators for elementary math
I think that a language and notation based on these few operators (and similar) can be considerably simpler and more expressive than conventional math or programming languages.
CZ is for me a stepping-stone toward this goal of an expressive relational graph language. It is more pleasant for me to develop software tools in CZ than in C or another language.
My CZ project has been stalled for quite some time. I foolishly became discouraged after receiving some negative feedback. I now know that honest negative feedback should be valued as an opportunity to improve, and I intend to continue the project until it lacks glaring faults, and is useful for other people. If this project or this article interests you, please contact me and let me know. It is much more enjoyable to work on a project when other people are actively interested in it!
The uBITX uses an Arduino internally. This article describes how to update its software.
Required hardware
The connector on the back is a Mini-B USB connector, so you'll need a "Mini-B to A" USB cable. This is not the same cable as used with older Android smartphones. The Mini-B connector was used with a lot of cameras a decade ago.
You'll also need a computer. I use a laptop with Fedora Linux installed.
Required software for software development
In Fedora all the required software is installed with sudo dnf install arduino git. Add yourself to the users and lock groups with sudo usermod -a -G users,lock $USER (on Debian-style systems use sudo usermod -a -G dialout,lock $USER). You'll need to log out and log in again for that to have an effect (if you want to see which groups you are already in, then use the id command).
Run arduino as your ordinary non-root user to create the directories used by the Arduino IDE. You can quit the IDE once it starts.
Obtain the uBITX software
$ cd ~/Arduino
$ git clone https://github.com/afarhan/ubitxv6.git ubitx_v6.1_code
Connect the uBITX to your computer
Plug in the USB cable and turn on the radio. Running dmesg will show the Arduino appearing as a "USB serial" device:
usb 1-1: new full-speed USB device number 6 using xhci_hcd
usb 1-1: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
usb 1-1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
usb 1-1: Product: USB Serial
usbcore: registered new interface driver ch341
usbserial: USB Serial support registered for ch341-uart
ch341 1-1:1.0: ch341-uart converter detected
usb 1-1: ch341-uart converter now attached to ttyUSB1
If you want more information about the USB device then use:
$ lsusb -d 1a86:7523
Bus 001 Device 006: ID 1a86:7523 QinHeng Electronics CH340 serial converter
In the last post I had started implementing an Unscented Kalman Filter for position and orientation tracking in OpenHMD. Over the Christmas break, I continued that work.
A Quick Recap
When reading below, keep in mind that the goal of the filtering code I’m writing is to combine 2 sources of information for tracking the headset and controllers.
The first piece of information is acceleration and rotation data from the IMU on each device, and the second is observations of the device position and orientation from 1 or more camera sensors.
The IMU motion data drifts quickly (at least for position tracking) and can’t tell which way the device is facing (yaw, but can detect gravity and get pitch/roll).
The camera observations can tell exactly where each device is, but arrive at a much lower rate (52Hz vs 500/1000Hz) and can take a long time to process (hundreds of milliseconds) to analyse to acquire or re-acquire a lock on the tracked device(s).
The goal is to acquire tracking lock, then use the motion data to predict the motion closely enough that we always hit the ‘fast path’ of vision analysis. The key here is closely enough – the more closely the filter can track and predict the motion of devices between camera frames, the better.
Integration in OpenHMD
When I wrote the last post, I had the filter running as a standalone application, processing motion trace data collected by instrumenting a running OpenHMD app and moving my headset and controllers around. That’s a really good way to work, because it lets me run modifications on the same data set and see what changed.
However, the motion traces were captured using the current fusion/prediction code, which frequently loses tracking lock when the devices move – leading to big gaps in the camera observations and more interpolation for the filter.
By integrating the Kalman filter into OpenHMD, the predictions are improved leading to generally much better results. Here’s one trace of me moving the headset around reasonably vigourously with no tracking loss at all.
Headset motion capture trace
If it worked this well all the time, I’d be ecstatic! The predicted position matched the observed position closely enough for every frame for the computer vision to match poses and track perfectly. Unfortunately, this doesn’t happen every time yet, and definitely not with the controllers – although I think the latter largely comes down to the current computer vision having more troubler matching controller poses. They have fewer LEDs to match against compared to the headset, and the LEDs are generally more side-on to a front-facing camera.
Taking a closer look at a portion of that trace, the drift between camera frames when the position is interpolated using the IMU readings is clear.
Headset motion capture – zoomed in view
This is really good. Most of the time, the drift between frames is within 1-2mm. The computer vision can only match the pose of the devices to within a pixel or two – so the observed jitter can also come from the pose extraction, not the filtering.
The worst tracking is again on the Z axis – distance from the camera in this case. Again, that makes sense – with a single camera matching LED blobs, distance is the most uncertain part of the extracted pose.
Losing Track
The trace above is good – the computer vision spots the headset and then the filtering + computer vision track it at all times. That isn’t always the case – the prediction goes wrong, or the computer vision fails to match (it’s definitely still far from perfect). When that happens, it needs to do a full pose search to reacquire the device, and there’s a big gap until the next pose report is available.
That looks more like this
Headset motion capture trace with tracking errors
This trace has 2 kinds of errors – gaps in the observed position timeline during full pose searches and erroneous position reports where the computer vision matched things incorrectly.
Fixing the errors in position reports will require improving the computer vision algorithm and would fix most of the plot above. Outlier rejection is one approach to investigate on that front.
Latency Compensation
There is inherent delay involved in processing of the camera observations. Every 19.2ms, the headset emits a radio signal that triggers each camera to capture a frame. At the same time, the headset and controller IR LEDS light up brightly to create the light constellation being tracked. After the frame is captured, it is delivered over USB over the next 18ms or so and then submitted for vision analysis. In the fast case where we’re already tracking the device the computer vision is complete in a millisecond or so. In the slow case, it’s much longer.
Overall, that means that there’s at least a 20ms offset between when the devices are observed and when the position information is available for use. In the plot above, this delay is ignored and position reports are fed into the filter when they are available. In the worst case, that means the filter is being told where the headset was hundreds of milliseconds earlier.
To compensate for that delay, I implemented a mechanism in the filter where it keeps extra position and orientation entries in the state that can be used to retroactively apply the position observations.
The way that works is to make a prediction of the position and orientation of the device at the moment the camera frame is captured and copy that prediction into the extra state variable. After that, it continues integrating IMU data as it becomes available while keeping the auxilliary state constant.
When a the camera frame analysis is complete, that delayed measurement is matched against the stored position and orientation prediction in the state and the error used to correct the overall filter. The cool thing is that in the intervening time, the filter covariance matrix has been building up the right correction terms to adjust the current position and orientation.
Here’s a good example of the difference:
Before: Position filtering with no latency compensationAfter: Latency-compensated position reports
Notice how most of the disconnected segments have now slotted back into position in the timeline. The ones that haven’t can either be attributed to incorrect pose extraction in the compute vision, or to not having enough auxilliary state slots for all the concurrent frames.
At any given moment, there can be a camera frame being analysed, one arriving over USB, and one awaiting “long term” analysis. The filter needs to track an auxilliary state variable for each frame that we expect to get pose information from later, so I implemented a slot allocation system and multiple slots.
The downside is that each slot adds 6 variables (3 position and 3 orientation) to the covariance matrix on top of the 18 base variables. Because the covariance matrix is square, the size grows quadratically with new variables. 5 new slots means 30 new variables – leading to a 48 x 48 covariance matrix instead of 18 x 18. That is a 7-fold increase in the size of the matrix (48 x 48 = 2304 vs 18 x 18 = 324) and unfortunately about a 10x slow-down in the filter run-time.
At that point, even after some optimisation and vectorisation on the matrix operations, the filter can only run about 3x real-time, which is too slow. Using fewer slots is quicker, but allows for fewer outstanding frames. With 3 slots, the slow-down is only about 2x.
There are some other possible approaches to this problem:
Running the filtering delayed, only integrating IMU reports once the camera report is available. This has the disadvantage of not reporting the most up-to-date estimate of the user pose, which isn’t great for an interactive VR system.
Keeping around IMU reports and rewinding / replaying the filter for late camera observations. This limits the overall increase in filter CPU usage to double (since we at most replay every observation twice), but potentially with large bursts when hundreds of IMU readings need replaying.
It might be possible to only keep 2 “full” delayed measurement slots with both position and orientation, and to keep some position-only slots for others. The orientation of the headset tends to drift much more slowly than position does, so when there’s a big gap in the tracking it would be more important to be able to correct the position estimate. Orientation is likely to still be close to correct.
Further optimisation in the filter implementation. I was hoping to keep everything dependency-free, so the filter implementation uses my own naive 2D matrix code, which only implements the features needed for the filter. A more sophisticated matrix library might perform better – but it’s hard to say without doing some testing on that front.
Controllers
So far in this post, I’ve only talked about the headset tracking and not mentioned controllers. The controllers are considerably harder to track right now, but most of the blame for that is in the computer vision part. Each controller has fewer LEDs than the headset, fewer are visible at any given moment, and they often aren’t pointing at the camera front-on.
Oculus Camera view of headset and left controller.
This screenshot is a prime example. The controller is the cluster of lights at the top of the image, and the headset is lower left. The computer vision has gotten confused and thinks the controller is the ring of random blue crosses near the headset. It corrected itself a moment later, but those false readings make life very hard for the filtering.
Position tracking of left controller with lots of tracking loss.
Here’s a typical example of the controller tracking right now. There are some very promising portions of good tracking, but they are interspersed with bursts of tracking losses, and wild drifting from the computer vision giving wrong poses – leading to the filter predicting incorrect acceleration and hence cascaded tracking losses. Particularly (again) on the Z axis.
Timing Improvements
One of the problems I was looking at in my last post is variability in the arrival timing of the various USB streams (Headset reports, Controller reports, camera frames). I improved things in OpenHMD on that front, to use timestamps from the devices everywhere (removing USB timing jitter from the inter-sample time).
There are still potential problems in when IMU reports from controllers get updated in the filters vs the camera frames. That can be on the order of 2-4ms jitter. Time will tell how big a problem that will be – after the other bigger tracking problems are resolved.
Sponsorships
All the work that I’m doing implementing this positional tracking is a combination of my free time, hours contributed by my employer Centricular and contributions from people via Github Sponsorships. If you’d like to help me spend more hours on this and fewer on other paying work, I appreciate any contributions immensely!
Next Steps
The next things on my todo list are:
Integrate the delayed-observation processing into OpenHMD (at the moment it is only in my standalone simulator).
Improve the filter code structure – this is my first kalman filter and there are some implementation decisions I’d like to revisit.
Publish the UKF branch for other people to try.
Circle back to the computer vision and look at ways to improve the pose extraction and better reject outlying / erroneous poses, especially for the controllers.
Think more about how to best handle / schedule analysis of frames from multiple cameras. At the moment each camera operates as a separate entity, capturing frames and analysing them in threads without considering what is happening in other cameras. That means any camera that can’t see a particular device starts doing full pose searches – which might be unnecessary if another camera still has a good view of the device. Coordinating those analyses across cameras could yield better CPU consumption, and let the filter retain fewer delayed observation slots.
udev can be used to block a USB device (or even an entire class of devices, such as USB storage). Add a file /etc/udev/rules.d/99-local-blacklist.rules containing:
While I hope to update this site again soon, here’s a photo I captured over the weekend in my back yard. The red flowering plant is attracting wattlebirds and honey-eaters. This wattlebird stayed still long enough for me to take this shot. After a little bit of editing, I think it has turned out rather well.
Photo taken with: Canon 7D Mark II & Canon 55-250mm lens.
Edited in Lightroom and Photoshop (to remove a sun glare spot off the eye).
Digital TV uses MPEG Transport Stream, which is a container for video designed for lossy transmission, such as radio. To save CPU cycles, Personal Video Records often save the MPEG-TS stream directly to disk. The more usual MPEG is technically MPEG Program Stream, which is designed for lossless transmission, such as storage on a disk.
Since these are a container formats, it should be possible to losslessly and quickly re-code from MPEG-TS to MPEG-PS.
I gave the talk Practicality Beats Purity: The Zen of Python’s Escape Hatch as part of PyConline AU 2020, the very online replacement for PyCon AU this year. In that talk, I included a few interesting links code samples which you may be interested in:
__NOT_A_MATCHER__=object()__MATCHER_SORT_KEY__=0defswitch(cls):inst=cls()methods=[]forattrindir(inst):method=getattr(inst,attr)matcher=getattr(method,"__matcher__",__NOT_A_MATCHER__)ifmatcher==__NOT_A_MATCHER__:continuemethods.append(method)methods.sort(key=lambdai:i.__matcher_sort_key__)formethodinmethods:matches=method.__matcher__()ifmatches:returnmethod()raiseValueError(f"No matcher matches value {test_value}")defcase(matcher):def__decorator__(f):global__MATCHER_SORT_KEY__f.__matcher__=matcherf.__matcher_sort_key__=__MATCHER_SORT_KEY____MATCHER_SORT_KEY__+=1returnfreturn__decorator__if__name__=="__main__":foriinrange(100):@switchclassFizzBuzz:@case(lambda:i%15==0)deffizzbuzz(self):return"fizzbuzz"@case(lambda:i%3==0)deffizz(self):return"fizz"@case(lambda:i%5==0)defbuzz(self):return"buzz"@case(lambda:True)defdefault(self):return"-"print(f"{i}{FizzBuzz}")
fuck grey text on white backgrounds
fuck grey text on black backgrounds
fuck thin, spindly fonts
fuck 10px text
fuck any size of anything in px
fuck font-weight 300
fuck unreadable web pages
fuck themes that implement this unreadable idiocy
fuck sites that don’t work without javascript
fuck reactjs and everything like it
thank fuck for Stylus. and uBlock Origin. and uMatrix.
Earlier today I launched this site. It is the result of a lot of work over the past few weeks. It began as an idea to publicise some of my photos, and morphed into the site you see now, including a store and blog that I’ve named “Photekgraddft”.
In the weirdly named blog, I want to talk about photography, the stories behind some of my more interesting shots, the gear and software I use, my technology career, my recent ADHD diagnosis and many other things.
This scares me quite a lot. I’ve never really put myself out onto the internet before. If you Google me, you’re not going to find anything much. Google Images has no photos of me. I’ve always liked it that way. Until now.
ADHD’ers are sometimes known for “oversharing”, one of the side-effects of the inability to regulate emotions well. I’ve always been the opposite, hiding, because I knew I was different, but didn’t understand why.
The combination of the COVID-19 pandemic and my recent ADHD diagnosis have given me a different perspective. I now know why I hid. And now I want to engage, and be engaged, in the world.
If I can be a force for positive change, around people’s knowledge and opinion of ADHD, then I will.
If talking about Business Analysis (my day job), and sharing my ideas for optimising organisations helps anyone at all, then I will.
If I can show my photos and brighten someone’s day by allowing them to enjoy a sunset, or a flying bird, then I will.
And if anyone buys any of my photos, then I will be shocked!
So welcome to my little vanity project. I hope it can be something positive, for me, if for noone else in this new, odd world in which we now find ourselves living together.
Some time ago, I wrote “floats, bits, and constant expressions” about converting floating point number into its representative ones and zeros as a C++ constant expression – constructing the IEEE 754 representation without being able to examine the bits directly.
I’ve been playing around with Rust recently, and rewrote that conversion code as a bit of a learning exercise for myself, with a thoroughly contrived set of constraints: using integer and single-precision floating point math, at compile time, without unsafe blocks, while using as few unstable features as possible.
I’ve included the listing below, for your bemusement and/or head-shaking, and you can play with the code in the Rust Playground and rust.godbolt.org
// Jonathan Adamczewski 2020-05-12
//
// Constructing the bit-representation of an IEEE 754 single precision floating
// point number, using integer and single-precision floating point math, at
// compile time, in rust, without unsafe blocks, while using as few unstable
// features as I can.
//
// or "What if this silly C++ thing https://brnz.org/hbr/?p=1518 but in Rust?"
// Q. Why? What is this good for?
// A. To the best of my knowledge, this code serves no useful purpose.
// But I did learn a thing or two while writing it :)
// This is needed to be able to perform floating point operations in a const
// function:
#![feature(const_fn)]
// bits_transmute(): Returns the bits representing a floating point value, by
// way of std::mem::transmute()
//
// For completeness (and validation), and to make it clear the fundamentally
// unnecessary nature of the exercise :D - here's a short, straightforward,
// library-based version. But it needs the const_transmute flag and an unsafe
// block.
#![feature(const_transmute)]
const fn bits_transmute(f: f32) -> u32 {
unsafe { std::mem::transmute::<f32, u32>(f) }
}
// get_if_u32(predicate:bool, if_true: u32, if_false: u32):
// Returns if_true if predicate is true, else if_false
//
// If and match are not able to be used in const functions (at least, not
// without #![feature(const_if_match)] - so here's a branch-free select function
// for u32s
const fn get_if_u32(predicate: bool, if_true: u32, if_false: u32) -> u32 {
let pred_mask = (-1 * (predicate as i32)) as u32;
let true_val = if_true & pred_mask;
let false_val = if_false & !pred_mask;
true_val | false_val
}
// get_if_f32(predicate, if_true, if_false):
// Returns if_true if predicate is true, else if_false
//
// A branch-free select function for f32s.
//
// If either is_true or is_false is NaN or an infinity, the result will be NaN,
// which is not ideal. I don't know of a better way to implement this function
// within the arbitrary limitations of this silly little side quest.
const fn get_if_f32(predicate: bool, if_true: f32, if_false: f32) -> f32 {
// can't convert bool to f32 - but can convert bool to i32 to f32
let pred_sel = (predicate as i32) as f32;
let pred_not_sel = ((!predicate) as i32) as f32;
let true_val = if_true * pred_sel;
let false_val = if_false * pred_not_sel;
true_val + false_val
}
// bits(): Returns the bits representing a floating point value.
const fn bits(f: f32) -> u32 {
// the result value, initialized to a NaN value that will otherwise not be
// produced by this function.
let mut r = 0xffff_ffff;
// These floation point operations (and others) cause the following error:
// only int, `bool` and `char` operations are stable in const fn
// hence #![feature(const_fn)] at the top of the file
// Identify special cases
let is_zero = f == 0_f32;
let is_inf = f == f32::INFINITY;
let is_neg_inf = f == f32::NEG_INFINITY;
let is_nan = f != f;
// Writing this as !(is_zero || is_inf || ...) cause the following error:
// Loops and conditional expressions are not stable in const fn
// so instead write this as type coversions, and bitwise operations
//
// "normalish" here means that f is a normal or subnormal value
let is_normalish = 0 == ((is_zero as u32) | (is_inf as u32) |
(is_neg_inf as u32) | (is_nan as u32));
// set the result value for each of the special cases
r = get_if_u32(is_zero, 0, r); // if (iz_zero) { r = 0; }
r = get_if_u32(is_inf, 0x7f80_0000, r); // if (is_inf) { r = 0x7f80_0000; }
r = get_if_u32(is_neg_inf, 0xff80_0000, r); // if (is_neg_inf) { r = 0xff80_0000; }
r = get_if_u32(is_nan, 0x7fc0_0000, r); // if (is_nan) { r = 0x7fc0_0000; }
// It was tempting at this point to try setting f to a "normalish" placeholder
// value so that special cases do not have to be handled in the code that
// follows, like so:
// f = get_if_f32(is_normal, f, 1_f32);
//
// Unfortunately, get_if_f32() returns NaN if either input is NaN or infinite.
// Instead of switching the value, we work around the non-normalish cases
// later.
//
// (This whole function is branch-free, so all of it is executed regardless of
// the input value)
// extract the sign bit
let sign_bit = get_if_u32(f < 0_f32, 1, 0);
// compute the absolute value of f
let mut abs_f = get_if_f32(f < 0_f32, -f, f);
// This part is a little complicated. The algorithm is functionally the same
// as the C++ version linked from the top of the file.
//
// Because of the various contrived constraints on thie problem, we compute
// the exponent and significand, rather than extract the bits directly.
//
// The idea is this:
// Every finite single precision float point number can be represented as a
// series of (at most) 24 significant digits as a 128.149 fixed point number
// (128: 126 exponent values >= 0, plus one for the implicit leading 1, plus
// one more so that the decimal point falls on a power-of-two boundary :)
// 149: 126 negative exponent values, plus 23 for the bits of precision in the
// significand.)
//
// If we are able to scale the number such that all of the precision bits fall
// in the upper-most 64 bits of that fixed-point representation (while
// tracking our effective manipulation of the exponent), we can then
// predictably and simply scale that computed value back to a range than can
// be converted safely to a u64, count the leading zeros to determine the
// exact exponent, and then shift the result into position for the final u32
// representation.
// Start with the largest possible exponent - subsequent steps will reduce
// this number as appropriate
let mut exponent: u32 = 254;
{
// Hex float literals are really nice. I miss them.
// The threshold is 2^87 (think: 64+23 bits) to ensure that the number will
// be large enough that, when scaled down by 2^64, all the precision will
// fit nicely in a u64
const THRESHOLD: f32 = 154742504910672534362390528_f32; // 0x1p87f == 2^87
// The scaling factor is 2^41 (think: 64-23 bits) to ensure that a number
// between 2^87 and 2^64 will not overflow in a single scaling step.
const SCALE_UP: f32 = 2199023255552_f32; // 0x1p41f == 2^41
// Because loops are not available (no #![feature(const_loops)], and 'if' is
// not available (no #![feature(const_if_match)]), perform repeated branch-
// free conditional multiplication of abs_f.
// use a macro, because why not :D It's the most compact, simplest option I
// could find.
macro_rules! maybe_scale {
() => {{
// care is needed: if abs_f is above the threshold, multiplying by 2^41
// will cause it to overflow (INFINITY) which will cause get_if_f32() to
// return NaN, which will destroy the value in abs_f. So compute a safe
// scaling factor for each iteration.
//
// Roughly equivalent to :
// if (abs_f < THRESHOLD) {
// exponent -= 41;
// abs_f += SCALE_UP;
// }
let scale = get_if_f32(abs_f < THRESHOLD, SCALE_UP, 1_f32);
exponent = get_if_u32(abs_f < THRESHOLD, exponent - 41, exponent);
abs_f = get_if_f32(abs_f < THRESHOLD, abs_f * scale, abs_f);
}}
}
// 41 bits per iteration means up to 246 bits shifted.
// Even the smallest subnormal value will end up in the desired range.
maybe_scale!(); maybe_scale!(); maybe_scale!();
maybe_scale!(); maybe_scale!(); maybe_scale!();
}
// Now that we know that abs_f is in the desired range (2^87 <= abs_f < 2^128)
// scale it down to be in the range (2^23 <= _ < 2^64), and convert without
// loss of precision to u64.
const INV_2_64: f32 = 5.42101086242752217003726400434970855712890625e-20_f32; // 0x1p-64f == 2^64
let a = (abs_f * INV_2_64) as u64;
// Count the leading zeros.
// (C++ doesn't provide a compile-time constant function for this. It's nice
// that rust does :)
let mut lz = a.leading_zeros();
// if the number isn't normalish, lz is meaningless: we stomp it with
// something that will not cause problems in the computation that follows -
// the result of which is meaningless, and will be ignored in the end for
// non-normalish values.
lz = get_if_u32(!is_normalish, 0, lz); // if (!is_normalish) { lz = 0; }
{
// This step accounts for subnormal numbers, where there are more leading
// zeros than can be accounted for in a valid exponent value, and leading
// zeros that must remain in the final significand.
//
// If lz < exponent, reduce exponent to its final correct value - lz will be
// used to remove all of the leading zeros.
//
// Otherwise, clamp exponent to zero, and adjust lz to ensure that the
// correct number of bits will remain (after multiplying by 2^41 six times -
// 2^246 - there are 7 leading zeros ahead of the original subnormal's
// computed significand of 0.sss...)
//
// The following is roughly equivalent to:
// if (lz < exponent) {
// exponent = exponent - lz;
// } else {
// exponent = 0;
// lz = 7;
// }
// we're about to mess with lz and exponent - compute and store the relative
// value of the two
let lz_is_less_than_exponent = lz < exponent;
lz = get_if_u32(!lz_is_less_than_exponent, 7, lz);
exponent = get_if_u32( lz_is_less_than_exponent, exponent - lz, 0);
}
// compute the final significand.
// + 1 shifts away a leading 1-bit for normal, and 0-bit for subnormal values
// Shifts are done in u64 (that leading bit is shifted into the void), then
// the resulting bits are shifted back to their final resting place.
let significand = ((a << (lz + 1)) >> (64 - 23)) as u32;
// combine the bits
let computed_bits = (sign_bit << 31) | (exponent << 23) | significand;
// return the normalish result, or the non-normalish result, as appopriate
get_if_u32(is_normalish, computed_bits, r)
}
// Compile-time validation - able to be examined in rust.godbolt.org output
pub static BITS_BIGNUM: u32 = bits(std::f32::MAX);
pub static TBITS_BIGNUM: u32 = bits_transmute(std::f32::MAX);
pub static BITS_LOWER_THAN_MIN: u32 = bits(7.0064923217e-46_f32);
pub static TBITS_LOWER_THAN_MIN: u32 = bits_transmute(7.0064923217e-46_f32);
pub static BITS_ZERO: u32 = bits(0.0f32);
pub static TBITS_ZERO: u32 = bits_transmute(0.0f32);
pub static BITS_ONE: u32 = bits(1.0f32);
pub static TBITS_ONE: u32 = bits_transmute(1.0f32);
pub static BITS_NEG_ONE: u32 = bits(-1.0f32);
pub static TBITS_NEG_ONE: u32 = bits_transmute(-1.0f32);
pub static BITS_INF: u32 = bits(std::f32::INFINITY);
pub static TBITS_INF: u32 = bits_transmute(std::f32::INFINITY);
pub static BITS_NEG_INF: u32 = bits(std::f32::NEG_INFINITY);
pub static TBITS_NEG_INF: u32 = bits_transmute(std::f32::NEG_INFINITY);
pub static BITS_NAN: u32 = bits(std::f32::NAN);
pub static TBITS_NAN: u32 = bits_transmute(std::f32::NAN);
pub static BITS_COMPUTED_NAN: u32 = bits(std::f32::INFINITY/std::f32::INFINITY);
pub static TBITS_COMPUTED_NAN: u32 = bits_transmute(std::f32::INFINITY/std::f32::INFINITY);
// Run-time validation of many more values
fn main() {
let end: usize = 0xffff_ffff;
let count = 9_876_543; // number of values to test
let step = end / count;
for u in (0..=end).step_by(step) {
let v = u as u32;
// reference
let f = unsafe { std::mem::transmute::<u32, f32>(v) };
// compute
let c = bits(f);
// validation
if c != v &&
!(f.is_nan() && c == 0x7fc0_0000) && // nans
!(v == 0x8000_0000 && c == 0) { // negative 0
println!("{:x?} {:x?}", v, c);
}
}
}
