Connected Little Boxes Teaching at the Hardware Meetup

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If you want to learn how to write MicroPython for the Raspberry Pi PICO I might have just the thing for you. I’ve made a website you can find at clbteaching.com. The idea is that you open the web site, plug your PICO into your computer, click CONNNECT, pick an exercise and off you go. Each exercise has step by step instructions and sample code. You can deploy code into your device and run it directly from the browser, with no need to load anything onto your machine.

There are two levels. The first level is simple input/output and getting used to running Python, the second level is using the Connected Little Boxes framework to create devices with complex hardware interactions. There’s even a button you can press to load all the framework code onto your device so you can use it. Then you can load managers into an application and start making things. You can find the actual code behind the site here. The actual Connected Little Boxes site (where you can find out all about the framework) is here.

To get started you just need a Raspberry Pi PICO running MicroPython, which you can find here. You also need to be running a browser which supports serial communications, for example Edge or Chrome.

It is a work in progress at the moment. There are place holders for some images. The buttons are not very well organised. But I think it works well enough to be an Alpha release. I’d love for you to have a go and let me know what you think. There’s a large red FEEDBACK button you can use to raise issues.

I’ve enjoyed building this, so I’m already ahead of the game. I’d love to think of it as being useful too. I’m going to be adding more labs and refining the ones that are there.

We’re going to be working through the content at our Hardware Meetups. I’ll let you know how we get on. If you fancy coming along to a meetup and having a go yourself, our next meetup is next week on Wednesday 27th May in Hull Makerspace in the Hull Central Library in, surprise, surprise, Hull. Starting at around 17:00.

Sheep Detectives does the job

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Can you spot the crook?

“Cosy crime” is all the rage. And people like sheep. So why not have talking sheep solve a murder? This idea is stretched over a movie that just about gets away with it. The animation is pretty impressive, the human characters are suitably shifty. And there is even some analogue photography (which is also all the rage). Worth a trip if you are prepared to manage your expectations appropriately.

Flexi-curve memories

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When I was learning physics I found my flexi-curve invaluable. Every now and then I did an experiment to prove something or other. Proof of a successful outcome was usually a straight line of readings plotted on a graph. Of course, this hardly ever happened to me. But by bending my flexi-curve carefully through my points and drawing a nice thick line I could give the impression of something mostly straight and that was usually good enough.

I was reminded of my flexi-curve today as I was writing something about bSpline curves which do this kind of line bending for you. I had a look around and it turns out you can still buy flexi-curves. Although this particular product doesn’t have a very good review (but the review is worth reading for a giggle).

What on earth is rubato?

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There’s a particular TV theme that I’ve been wanting to play on the piano for ages. Today I managed to get hold of a copy of the music.

Three flats.

This is a bit of a pain. Every E, B and A that I play must be flattened. It never goes well when I attempt audience participation on this blog (I’ll refrain from mentioning the obvious reason for this). But anyhoo, anyone got an idea what the TV show is from the above?

Best laid plans of idiots

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You can see the hole in the middle of the corner of the turn at the top. you can also see my unsucessful soldering attempts

I don’t like it when things go wrong because I didn’t do something. But I really don’t like it when things go wrong because I did something. Especially if the thing that I did was intended to stop the first thing from going wrong. Confused? Me too. Let’s step back a bit.

I really like my Apple Newton eMate 300 devices. But they have a stock fault which can destroy them.

Mended Hinges

These are the hinges that hold the display onto the eMate. Around the shaft in each hinge is a metal spring which grips the shaft and adds friction so that when you open the hinge it stays open. The spring grips the shaft with just enough force to hold the display in place after you’ve opened it. So far, so good. Now wind the clock forward around 30 years. The grease that was fitted to the shafts turns solid, the shafts become sticky and the springs wrap themselves ever more tightly around the shafts. Until one day you close the display and the top of the spring is forced out from behind the bolt holding it in place. The top of the spring now pushes into the ribbon cable linking the display to the body of the eMate and makes a hole in it, breaking a bunch of tracks. Sometimes the display stops working, sometimes the touch screen stops working. Either way this is a bad thing.

I spent yesterday with my eMates dismantling them, putting oil on the hinges and adding a washer behind the retaining bolt to prevent the springs from escaping from the hinges. I went to bed last night thinking that I had solved the problem. I woke up today and discovered that the touch screen on one of the eMates was broken. Wah!

Turns out that my repair had prevented the end of the spring from popping out. But the spring itself broke, releasing the top of the screen and destroying the cable. I’ve fixed the cause of the problem. I’ve dismantled the hinge completely (something I should have done yesterday), cleaned and lubricated the hinge shaft and adjusted the spring tension by bending the springs a bit. But it is too late for this ribbon cable. I had a go at soldering some tracks around the broken bits but I just don’t have the skills.

Fortunately Joe’s Computer Museum has my back. This is such a common problem that Joe has taken it upon himself to trace the circuit and get a bunch of replacement cables made. I’ve ordered one. Perhaps I should have got a few.

If you have an eMate 300 you should make sure you sort out the hinges. If the lid becomes hard to open, or if you hear a click or bang while opening or closing it you should immediately stop moving the lid and check that the hinge springs aren’t on the prowl. You can find a good description of what to do here.

Working with Claude

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I’m really enjoying working with Claude. I’ve signed up for the cheapest tier (around 18 pounds a month) and we have been building a solution together for the last week or so. I’ve been using Claude Code which plugs into Visual Studio Code very nicely.

I explain what I want the code to do and Claude makes it for me. Quite often it asks for clarification, then it asks for permission to do things, and then it does them. It works directly on your Visual Studio Project (and your PC if you let it). It seems a bit less anxious to please than ChatGPT and hardly ever tells me that something I’ve suggested is a good idea, which I like a lot. It also seems to get things right first time too, which is really nice.

But the best thing about it is the way that it is metered. The first time I discovered this was a bit of a shock. Claude was in the middle of doing something and it just stopped. Like the cooker thing on the moon in Wallace and Gromit’s “Grand Day Out” film when the money runs out. Turns out I’d used my five hour allocation in about an hour and a half, and I had to wait for my next five hour slot to arrive.

At the time I was a bit cross about this, but now I like it. It means that I plan my work a lot more. If I run out of time in a slot I spend the rest of the time writing a detailed specification, or testing what has been produced. Or, better yet, doing nothing. If Claude was available all the time I don’t think I’d ever stop.

I thought I was being clever when I started giving Claude something to do just after I got up so that my morning slot would end around lunchtime and I could have another five hours worth on the afternoon. But then I discovered that there is also a weekly allocation, and if you hit the end of that you have wait for the next week to come around before you can do anything, which would be a pain. So now I track that carefully.

There is a really useful tool here you can use to track your Claude usage. It works very well, although I ended up with a blank dashboard until I performed the fix described here.

It turns out that your usage is all abut tokens. Everything you send to Claude ends up as a token. Everything Claude sends back to you is sent as tokens. A word in a conversation ends up as a token that is sent to Claude. If you are having a conversation with Claude and you ask it another question the entire previous conversation is sent to Claude along with your new question.

This means that long chats can end up costing a lot. If you are starting something new, start it in a new conversation, don’t tag it onto the end of an existing one. You can also ask Claude to summarise your chat and then use that summary to start a new conversation, which should cut down on token use too.

If you have three things you want Claude to do, ask for them all at once. This reduces the number of times you will have to tell Claude what you want and thus the number of tokens used. For me this seemed counter intuitive at first. When I was using ChatGPT I found that if I asked it to perform multiple tasks it would forget to do some of them. Claude is much better in this respect. It seems to use the additional tasks as extra context too.

Finally, avoid peak hours, which for the UK seems to mean between 13:00 and 19:00 at the moment.

Claude has changed the way I work even more that ChatGPT did. I hear that ChatGPT now has a code writing tool too, I’m looking forward to having a go with that.

Film Holder Fun

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What do you do if you happen to acquire a Columbia Pecto No. 5 camera from 1897? You design and 3D print some Instax instant film holders for it. Or at least, that’s what I’ve done. You can see the design for the film holder above. I’ve made it out of multiple layers that fit together because when you are 3D printing it is important to try and avoid “overhangs” (areas that are not supported underneath).

It seems to work OK. If you have a need for a film holders like these (which I admit is unlikely) you can find all the files here.

MOT Test Terrors

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When I was much younger the annual Ministry of Transport (MOT) test was a big thing. I’d take my decaying Mini down to a garage and watch them chip paint and rust off it, test the lights, steering and the brakes and give the seatbelts a good tug. Then they’d tell me about about the worn bearings, loose steering kingpins and other things I’d been happily motoring around on for the last year. They didn’t mind about the hole in floor though, because apparently that wasn’t structural.

One time I was telling dad about what had gone wrong (in this case the bushes on the rear radius arms that hold on the rear wheels).He looked up from his paper and told me it sounded like a big job, so I should probably find somewhere to get them fixed. At which point I was forced to tell him that my car was in his garage with the rear suspension missing. He shuddered and went back to his paper. I had to go around all the local car dealers until I found someone who could drill out the radius arms and put in replacement bushes.

I got it fixed that time but the following year, when I took it for a test just after I’d replaced the silencer (muffler) because it fell off on the way to a party, I was forced to admit defeat (subframe mounts) and throw the car away. Oh well, at least it had the newest silencer in the scrapyard.

I was reminded of all this yesterday because my car was due for it’s annual test. It seems a lot more relaxing these days. I think cars are just better made (and painted) than they used to be. All I needed was a couple of tyres and a rear windscreen wiper. Good times.

Apple Newton eMate 300

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I really need to clean the screen up a bit.

I now have yet another obsession. It’s the Apple Messenger eMate 300. Last week I bought, er, four of them (at a very knock down price). I’ve given one away, so now I have three to get going. Apple sold them in 1997 for use in schools. They have a backlit touch lcd, pleasing little keyboard and built in office tools. You can open your eMate and start typing the instant you see the screen appear. Then you can keep typing on battery power for around 24 hours (assuming the batteries are in good condition).This is not something you can do with any laptop you can buy today. Progress eh?

The eMate is an interesting historical artefact because it was the first thing designed for Apple by Johnny Ive, who went on to create the translucent macs, lots of iPods and many of the iconic products that made Apple what it is today.

Anyhoo, I’m learning a lot about the device, mostly at the moment about how it can break. It looks pretty sturdy (it was designed for classroom use) and the electronics seem fairly standard. I’m going to have to figure out how to get things off it, but at the moment I’m just happy typing text in on the little screen and learning how to draw bitmap graphics.

AI Images

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I’ve got this Raspberry Pi connected to an e-ink frame. I’ve written a little program that generates random text prompts from a set of keywords. The text gets fed into a copy of Stable Diffusion and every few hours a new picture appears. It’s quite fun. Today I added a little web server to the app so that I can view past pictures. None of them are very good, but I find them fascinating.