Schrodinger's Revenge

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Yesterday I was waiting for a battery to arrive so that I could discover whether I had a working camera (yay!) or a broken one (boo!). Of course, just because there are two outcomes doesn’t make them both equally likely, so I should have been prepared for brokenness. Which is what I got. Wah. So it was off with the top and…

It’s probably one of these wires…

A bit of experimentation with a multi-meter left me thinking that no power was getting to the system.

…or more likely this one.

One problem with old cameras is that chemicals leak out of the battery and corrode connections, which is what has happened here. So all I have to do is find the battery terminal and solder this wire back on. Or, replace the wire completely - which is what I ended up doing. So now, with the battery check light showing a happy green, I’d fixed the camera, right?

Wrong. The metering was all broken and the shutter didn’t open and close how it should. Turns out that my camera has succumbed to “The Pad of Death”. This is a thing with Yashica Electro 35 cameras. The shutter mechanism uses a tiny foam pad to transfer movement from one lever to another. But, plastic foam being what it is, after a while it turns to dust. No pad, no movement, broken camera.

There should be a foam pad where that pink yuccky stuff is

I had great fun fixing this. If by “great fun” you mean “nearly went insane rolling up small pads of tape and then trying to fit them into the slot between the two parts”. If it breaks again the camera will end up being a “display piece”. Or going on eBay as “sold for parts”.

Newly fitted pad. I hope the glue holds…

Anyhoo, I prevailed and now the meter is doing an impression of something that might be working. I’ll to some proper testing tomorrow, for now I’m happy that I get longer clicks with darker subjects. To be honest (why on earth to people say that - it’s like saying “I was thinking of telling you a lie, but I’ve changed my mind”) I don’t mind if the camera is not quite right yet. I’ve quite enjoyed fiddling with it - pad of death not withstanding - and I’ve gained a lot of respect for the people who designed and made this marvel of mechanics and early solid state electronics. I’m sure they didn’t expect folks to still be trying to use them 50 years after manufacture. It’s a tribute to them that they still mostly work.

Making Stuff Tech Session

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I used the converted polaroid camera to take some audience pictures but the ambient light was too strong, so we got a lot of blur. I also added a red cast which you can just about see.

We had a lot of fun at the Tech Session tonight. Rory did a splendid talk on testing, which put software testing into a properly useful context, and then I talked for 45 minutes on the joy of making stuff and what I’ve been up to lately.

For anyone who wants to know what I was on about, I’ll record a screencast (with all of the demos) later this week. You can find out about upcoming Tech Sessions here.

In the Money?

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I got a strange email this evening from a bunch of lawyers. It’s about the Anthropic Copyright Settlement. This is a class action brought on behalf of authors whose work allegedly appeared in a couple of allegedly pirate datasets that were allegedly used by Anthropic to train their AI systems. Allegedly. Anyhoo, I searched their database and 7 of my books were identified…

The settlement amount was 1.5 Billion dollars, but individual authors only get a tiny percentage of this. It’s nice to see some action being taken on behalf of creatives who have had their work used in this way but I reckon we still have a long way to go. Or at least, we should have. Now I get to fill in a form and wait until the end of April next year for the next phase of the process. I just hope I get enough to buy a camera…..

Colour Film Processing Fun

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If you are wondering what is special about the picture above, its that I actually developed it myself. I’ve done a lot of black and white processing but I’ve always avoided colour because it just sounds too scary. But now you can get chemicals which only need two baths. This makes working with colour very like working with black and white, where you usually need dip the film in developer and fixer.

The only other problem with colour processing is that you need to keep the chemicals at a specific temperature; in our case 35 degrees centigrade. We did this by using a new fangled cooking tool called a “sous vide” which heats and circulates water around a bath we made from a plastic box. All we had to do was drop the bottles of developer and “blix” (bleach and fixer) into the bath and leave them there for a while, and then keep the developing tank in the bath while the film was being processed.

The whole thing went very well; once we’d mixed up the chemicals which took a little while. In all we developed four films. The chemicals should be good for another 8, and we might be able to develop even more if we increase the development time still further. I can’t really tell the difference between our negatives and ones from “proper” film processing places. By doing four films we’ve kind of broken even on the cost of the chemicals against sending the fillm away, the next few should see us moving into proper savings. Great fun. Just remember to wear gloves and work in a well-ventilated area.

Birmingham Comicon

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You will practice your saxophone

We went to Birmingham Comicon today. It was great fun. The only thing I bought at the show was a year’s supply of saxophone lessons, and they weren’t actually on sale there, that was just a subscription I’d forgot to cancel that automatically renewed itself while I was in Birmingham. I hate it when they do that with no warning. But some good will come of this. I’m going to start practicing the saxophone again…

I took the big heavy camera too with a huge lens too. This proved very bad at getting focus, but I did get a few shots.

Hardware Meetup with lots of Python

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Please note that the time is not six past sixteen. And always wear shoes.

We had a very pleasant evening at the Hardware Meetup tonight. I was showing off the Connected Little Boxes Micro Python framework which is powering a couple of clocks that I’ve made. They worked great right up to the point where the input parser broke. Oh well.

Then it was off for dinner, which was great. Conversation turned to a study which has discovered that the brain has five ‘eras’ with one (a precipitous decline in the amount of “white matter” - whatever that means) starting at around my age. Then, when I got back to my car I discovered that I’d left my backpack in the restaurant. Perhaps the study is onto something….

Significant Other Charms

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These are the finished versions and they’ve printed quite well. The idea is that you have one, and you give your significant other, er, the other. Then, when you meet up you can fit them together (they do fit rather well). Each pair is completely unique (unless you print lots of them I suppose) and symbolises the uniqueness of whatever you think is unique about whatever your relationship is. Oh the romance of it all. I’m putting together some examples of writing Python code inside the FreeCAD design tool, and the charms are one of them. Another is my “Little City”.

Not bad for around 100 lines of code. The examples will all be going on GitHub soon.

Lytro Light Field Camera

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this is really what the cameras looks like

This little camera is like no other. Except perhaps the other Lytro camera (of which more later). It takes photographs as “light fields”. Rather than focusing an mage on a sensor, the Lytro uses tiny “micro lenses” in front of the sensor to create a pattern describing the light rays arriving at each point in the picture. Pictures are created by processing the light field pattern, which means that you can do funky things like focus a picture after you have taken it. You can even make videos of the focus changing…

The video above was created from a single Lytro picture. You make these using the Lytro application which you can download from here. You can even get this to run on Windows 11.

You can pick up Lytro cameras for not much money. I got one and the pictures and performance were rubbish. But then I upgraded the software to the most recent version and things got significantly better. If you get one and want to upgrade it you need to use the Lytro application which tries to fetch the upgrade firmware from a long dead Lytro site. But you can get round this by patching a code file to redirect update requests to a site that does have the required files. I did this and felt very “hackery”. You can find out more details here.

Look Ma! I’m patching a binary!

Light Field Photography was a fantastic idea which didn’t survive the collision with reality. The focus party trick is achieved at the expense of a huge downgrade in quality and the arrival of a whole bunch of image artefacts. That said, I quite like the pictures the camera makes, and you don’t need 20 megapixels for every photograph you take.

Lytro survived the indifferent reception of their first model to make another camera which had a much higher performance sensor and processor and produced much better pictures, but ultimately it was killed by smartphones providing the same kind of focus trickery by using depth cameras and lots of image processing. That said, it is fun to play with and if you are a camera nerd you could do worse that get one. You can find out more about the camera here.

MicroPython Connected Little Boxes

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All new lego logo

I’ve just released the latest incarnation of Connected Little Boxes. I’m in the process of converting the original C based system into MicroPython. I’ve got enough of it working to make it useful and now I’m looking for people to break it and tell me it’s rubbish.

You can find it here. If you have a spare Raspberry Pi PICO you might like to give it a spin.

Holey Stupid

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I’ve got a new desk. Gone are the bright red Ikea ones that weighed substantially less than the things we put on them. Now I have a big strong counter which hopefully won’t move much when I strap a steering wheel to it.

Anyhoo, I wanted some holes for cables to go through. And I also fancied the device above, which sets a rather useful mains socket and some powered usb ports into the desk. I discovered that these are 80mm diameter. So I asked for some holes which were 80mm diameter. Big mistake. Turns out that two things which are exactly the same size don’t fit together properly. The result you see above is the result of a bunch of frantic extra sanding on my part…

Tales of Yore: Toilet Flushing

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Inspired by a Discord post (which might be where all the good ideas come from) I thought I’d start a new series of intermittent blog posts about things I’ve done over the years. Starting, of course, with flushing toilets. The University of Hull used to have a “Centre for Applied Electronics” which was a technical “gun for hire”. Companies with problems would get in touch and we would go along and sort them out. Sometimes it was new product developments, sometimes it was automation or sensors. And sometimes it was toilets.

Reckit and Colman, a local chemical company, had built a lab containing toilets from all over the world. They made chemical tablets (also known as “loo blues”) which dissolve over time, releasing chemicals into a toilet each time it was flushed. These were clipped into the toilet bowl to keep things clean and fresh. The company wanted to know how well their tablets worked around the world. Rather than send someone out with a fistful of plane tickets and a case full of loo blues (I’d totally have done that job) they instead brought the world to a lab in Hull.

What they wanted was a way of producing timed flushes which mimic typical household use. Someone else built the actuators and I was called in to make the control system. At the start of the job the customer pointed to a manhole cover in the courtyard below the lab and said “If you flush all the toilets at once, that’s the cover that lifts up and floods everywhere. Don’t ask me now I know”.

I ended up programming a microcontroller in Forth to control the toilet actuators. It had quite a few timeouts in it. The controller was connected to a brand new (at the time) IBM PC XT. All the software was written in GW (Gee Whizz) BASIC which worked a treat. I discovered that the language had an ON TIMER GOSUB construction which let me build a system that allowed the user to edit and store time profiles while the toilets were being controlled in the background.

We installed the system and left them to it. We went back six months later and they told us they had a problem with the cathode ray tube (CRT) display “burning in” the screen. They asked what I could do about it and I pointed at the brightness control on the screen and suggested that they turn this down after use. In the end I added a screen timeout, mindful of the possibility that I would now get calls from people saying “The screen keeps going blank”.

Anyhoo, the system worked well for years, and I was rather cheered by the thought that, at any time of day or night a piece of my software could be flushing a toilet. Not a lot of programmers can say that.

A little bit of telemetry goes a long way

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def update(self):
        for name, mgr in self.manager_entries:
            start_time = time.ticks_ms()
            mgr.update()
            now = time.ticks_ms()
            mgr.update_time_ms=time.ticks_diff(now,start_time)
            self.status[name] = mgr.get_status()

This is the update loop for the Python version of the Connected Little Boxes software. It works through all the managers and updates them all. It also records how long each manager took to update and stores this value in the manager. I’ve found this to be incredibly valuable when trying to measure performance. When I display the status of the managers I also show the update_time value, which tells me who is slowing things down. When you make something that might be a bit performance sensitive its always worth adding a tiny bit of telemetry to find out what is going on.

Reverse Vibe Coding

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“Vibe coding” is apparently a phrase of the year. It describes a programming practice where you tell an AI system what you want a program to do and then AI writes the code for you. Then you test the code, it works perfectly, you embed it in a mission critical system and everyone lives happily ever after. Or not.

I’ve tried this a few times and what I end up doing is what I call “Reverse Vibe Coding”. I describe what I want, the AI makes something which mostly works. I describe what changes I think should be made to make it work properly, the AI then makes something new which may, or may not, be better. And then we repeat. There seem to be inflection points in the process where the AI can jump in massively the wrong direction and you have to kick it back on track. Rather than AI helping me solve my problem I end up helping AI solve its problems. This is kind of fun, but not usually very efficient. Although the AI probably learns a lot.

Hyper Japan Manchester

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We like Hyper Japan in London. So we thought we’d try Hyper Japan Manchester. The journey was different, in a car rather than on a “more exciting than we needed train”. But no less exciting as it turned out, thanks to the antics of Apple Maps navigation which insisted on taking us off the motorway so that we could enjoy some A-road action and a trip through Oldham that we didn’t expect. Then, when we needed it most in the middle of Manchester, the navigation had a complete meltdown spouting random instructions to head off down unknown streets and make sudden U-turns. I’ve no idea what caused it, but fortunately I kept my nerve and found the car park next to the venue.

You could say that the event was “more intimate” than the one in London. You could also say it was smaller. But it was no less interesting and enjoyable. Although we didn’t find anyone selling bubble tea. We got great stands, amazing musicianship and good food. Plus fantastic costumes. I’ve dropped some pictures down below. You can find all my Hyper Japan pictures here.