We had little Meetup tonight. Alifeee was there and we had a good chat about Connected Little Boxes (and Brian got his loaded with the new firmware and working). Alifeee has written a great article about the Hull Bus Sign project, which you can find here.
The next meetup will be on Wednesday 1st of November. I’ll be taking along my super-big camera to record the event - so be there if you want to be immortalised on proper film.
We will never know who won…
We had another go at Dominion tonight. The game crashed again. Right at the end, just before revealing the final scores. Wah. This has happened before. I’ve even made a program, DominionCalc which attempts to work out the scores from the player logs. Unfortunately the game that we played had a funky scoring mechanism involving the “Wild Hunt” card that doesn’t show up in the log. So we have to add some numbers in by hand now and the results might not be accurate. They really need to sort this out, we used to enjoy playing the game, but it is much less fun when you can’t work out definitively who has won.
I do like working in OPENSCAD
I’ve been investigating the scanning of Minox films. These films are a mere 9mm or so wide and the negatives are teeny tiny. I’ve been wondering if the distance of the negative from the scanner affects quality. To test the theory I made the film holder above. Each holder is a different distance from the scanner base. I’m 3D printing the holder, so I’ve made each one print layer (0.2mm) different from the other. I got the original height by measuring a PENSO holder I already had. It will be interesting to see if the different negative heights make a difference.
I asked DALl-E-2 for a picture of an undertaker doing plumbing. I think artists don’t have much to worry about at the moment….
Today I got asked the question “What is the future of work?” by Kofi at Radio Humberside. There’s a lot of concern about the machines taking over. I thought I’d write down what I was thinking.
Humans won’t be replaced by machines. Some human roles will be replaced by some machines. We really need to have a grown up discussion of the role of work in a fulfilled life. Perhaps that will mean holding back on automation. If people don’t have jobs to do, how will they get fulfilment?
Work will be different. We’ll use machines for the “easy” stuff and save the people for the hard bits. Knowing things might not be enough to get on in the world. Being able to describe things might not be enough. Being able to program might not be a long-term thing either, as machines get better at understanding what we want. I’ve got serious doubts about programs written by AI, but AI does make a great “keen assistant” which means we might need program writers. Not knowing about the new tools is not a plan. Figuring out how to use them is. Learn how to talk to the new AI. And get good at asking the machines questions. You can get a lot more out of them by asking your questions in the right way.
Just like electronic keyboards and music sequencers let lots of people into the music business back in the day, tools like ChatGPT can help people with ideas but nowhere to take them. If you need a business plan, a product description or even a devil’s advocate to spot flaws, then you should use AI. Keep having ideas. Keep doing things. Keep putting yourself out there. Look at everything you do and ask “How can I build my brand from this”. Don’t prepare to do one thing, prepare to do lots of things. And do lots of things to find out which ones you like.
And make you keep up to speed with the bad things that new technology makes possible. If you can use AI to write a business plan, you can also use it to write very plausible and personalised lies. And you can add very persuasive fake pictures and video too. The world is filling up with untruths and the people that distribute them don’t seem to care. So be careful out there..
Just Say No
It seemed an appealing purchase. I need a small Raspberry Pi to put inside a telephone (as you do) and this looked like it might offer a bit more power and connectivity than a Pi Zero. It arrived yesterday and I must say I’ve been completely underwhelmed by its performance. I was kind of hoping to be able to use remote development in Visual Studio Code to write and deploy Python code in the Pi. It doesn’t work. It never actually displays an error message. It just maxes out and then stops.
On the other hand the Pi Zero 2 that I got seems to work a lot better. I thought the devices would be broadly equivalent, but it seems that the zero is much better.
The film got a bit scratched as I was loading it
I love my little Minox camera. It takes tiny pictures on 9mm wide film. I make the film by slicing 35mm film into strips and then loading it into Minox cassettes. Then, once I’ve developed the film I scan the negatives. I use an Epson V750 scanner that I got a while back. It’s quite an old device, but the good news is that scanners age quite well (or at least I hope they do). To hold the negatives on the scanner I use a 3D printed PENSO mask. When I started scanning I got spectacularly bad results, with black streaks everywhere.
I’ve discovered that if I rotate the holders through ninety degrees on the scanner glass, so that they are in a “portrait” rather than a “landscape” orientation they work just fine. This must be due to the way that my scanner shines the light through the film when scanning.
I have no idea why this works, but I’m rather glad it does
This makes the camera a lot more useful…
Today, after a trip to the dentist for a filling (am I the only person who gets to the dentist half an hour early?), it was time to print yesterday’s lensboard design for my Micro-Press camera. It just fitted. I’m very pleased with myself, even though it was actually a pretty simple design. The board seems quite light-tight and my test pictures came out fine.
The hardest part of the job was finding where I’d put my black filament - the board nearly ended up being printed in shocking pink.
I might do another one with higher infill. This will make it slightly heftier and even more lighttight, but the camera was quite usable with the first version I printed. I’ll put the design on Thingiverse later for those many readers of my blog who have a need for a lensboard for a 1950’s Micro-Press press camera.
I already had some code that made rounded cornered plates
One of the truly great things about having a 3D printer is that if you have a need for something you can just print one. My “auction packed” camera arrived last week and today I thought I’d pop a lens in it so that I can try taking some pictures. For these type of cameras the lens is mounted on a plate called a “lensboard” which is then fitted into the camera. This makes it much easier to swap lenses when you are out and about. The camera didn’t come with a lens, but it did have a lensboard.
Unfortunately it was the wrong size. The hole in the middle was too big for the lens I wanted to use. So, I decided to make my own lensboard. I’ve made a quick version in OpenScad and tomorrow I’ll print it out and discover just how wrong it is.
The text in red is just the REPL code in ThONNY getting upset…
I love typing in interactive commands to the MicroPython REPL console. It makes development much easier as I can test out program constructions and even view the contents of variables after I have interrupted the code. But the problem is that I lose the REPL console when the program starts running. MindReader fixes that. It lets you type in Python statements which will be executed as your program is running.
To use it you add the MindReader class to your program. Then make an instance of the class (I called it m) and call m.update() in your program at regular intervals. The update method scans the serial port and builds up a command. When you press return it executes the command. This means that you can still type in REPL commands when your code is running, which is neat. You can enter print statements to view variables or even modify them for testing. I’ve found it very useful. You can find the code on GitHub here.
I’ll bring along a text display too.
I’m bringing a bunch of Connected Little Boxes to the Hardware Meetup next Wednesday. I want to show off the web configuration and deployment and what you can do with QR codes.
If you fancy coming along you can just turn up at Hull MakerSpace on Wednesday 11th of October from around 5:00 pm onwards. I’ll be around with some devices to show off, and even ones that you can take home with you (numbers permitting). It would be lovely to see you.
I’ve been making a circuit that lets a Raspberry PI PICO ring an old style telephone bell. Yesterday I discovered that voltage pulses generated in the coils that power the bell were destroying the MOSFETS that I was using to control the power. Today I got some diodes that I was able to fit across the coil connections. Now the bells ring out loud and clear. It’s so loud you can hear it next door. Which might not be a good thing.
I didn’t see any sparks though..
My MOSFETS arrived today. I connected them into a circuit that controls the power to a telephone bell using a Raspberry Pi PICO. They worked quite well. For a while. Then the ringing stopped. I was pretty sure what the problem was. It’s all to do with collapsing magnetic fields. The bell is operated by a coil which turns magnetic when you put power through it. This attracts the “donger” (for want of a better name) which strikes the bell making it ring. Then, the coil is turned off and another one turned on to move the “donger” in the opposite direction towards the other bell. If you do this around 20 times a second you get the ringing sound you get in old films and TV shows.
The snag is that when you turn off a circuit containing a coil the magnetic field the coil has generated collapses, and when it does this it induces a voltage in the coil. This behaviour is used to good effect in transformers and car ignition systems but in this case we end up with a bunch of voltage with nowhere particular to go except back up the wire into the MOSFET that just turned it off. Sometimes you get lucky and he pulse causes no damage. Other times you don’t. I’ve been kind of lucky. Only one of my MOSFETS is broken. The good news is that I know exactly what to do. I need to put a diode across the coils to short out any induced voltages and stop them causing damage.
They really knew how to make things back in the sixties
Started a new project today. I’m taking an old phone and making it more interesting. It’s going to have a Raspberry Pi inside along with extra circuitry to make the bell ring. Which is proving interesting. The bell in old phones is triggered by a 70 volt ac signal. Now, 70 volts is the far side of “tingly”. Anything below 50 volts is probably OK to grab hold of, but 70 could give you a shock you could do without. Especially at my age.
I’ve manged to get an inverter to convert 12 volts into a slightly less nerve jangling 35 volts or so. The plan is to drive the two coils that work the bell (you can just see them at the very top of the picture above) separately. So that I only use half the voltage. All I need is another MOSFET power driver (I’ve said this many times) so that I can control each coil individually. It should arrive tomorrow. I’ll add it to the circuit that I’ve already built which uses one MOSFET so that I can make the bell both “ding” and “dong”.
They are both jolly good reads
I’m in two magazines this month. Which is nice. If you pick up a copy of the latest HackSpace magazine you will find my article about creating a PICO Powered Bluetooth remote control for a light. This is known as the “milkshake” project because I put the device in an empty milkshake container. Delicious. Then, in MagPi magazine you can find a reprint of my article about making a chord keyboard. This is known as the “missing wires” project because I forgot to add some of the wiring to the design.
I’m going back to university. Just a little bit. I’m helping out with a MEng project. It will be nice to be back in the hallowed halls of learning once again. And the best thing is that, what with the turnover in students over the years, none of them have heard any of my jokes yet….
Well, why wouldn’t you want one of these….
I now see myself as a proper camera collector. Why have one camera that will do what you want when you can have lots of them, each of which does something different? Most of my camera buying action takes place on eBay, but today I had a taste of real life auctioning courtesy of Flints who run online auctions every now and then. I’ve been in the market for a large press camera that takes 4x5 negatives and they had one for sale that appeared only slightly broken. So I fired up the browser, logged into the site and hovered the cursor over the “Bid now” button.
It was great fun to watch. The auctioneer did a splendid job of keeping the whole thing moving along at a good pace, which was kind of important as there were around 500 lots to sell. After a couple of speculative bids on things that I wasn’t that bothered about “my” camera came up in lot 117. I was holding myself to all kinds of promises about not getting carried away and set a rigorous upper price limit. However, it was all a bit of an anti-climax. Nobody else seemed that bothered about the camera and so I got it for a smidge under the suggested lowest price. And that was that.
I watched the auction for a bit longer, but I was very good and didn’t buy anything else. The prices of items did seem impressive, but you had to remember that each item attracts a 30% premium that you had to pay on the sale price, plus VAT and carriage. My camera ended up costing me quite a bit more than the price I bid, but I reckon it is still a bit of a bargain. I’m rather looking forward to it arriving.
Taken with the phone. Oh the shame of it….
Today we were looking forward to spending some more time exploring Scarborough. But the weather had other ideas. Yesterday’s sunshine was replaced with grey drizzle, so we had to resort to pitching camp in a very nice café until it was time to catch the train home. But we’ll definitely be back.
This is a very clever poster.
We went to Scarborough today to see Constant Companions, a new play by Alan Ayckbourn. It’s a very human production about what happens when people and androids get together. For me it was a play of two halves. The first half was part farce and wry social commentary. The second part then runs the stories forward to their “logical” and somewhat heart rending conclusions, leaving me with lots to think about as we headed out of the theatre. The acting and staging were superb and the whole thing added up to the best night out that we’ve had in ages. Pro-tip: get your drinks and ice cream delivered to your seat during the interval for that “properly spoiled” experience.
The play is on for a little while longer. Seats are very keenly priced, the theatre and the staff are lovely and Scarborough is a great place to visit. Go see.
Not used Silk filament before. I rather like it
Did the final design of the Agile Octopus Tarff Display case today and printed it out. It looks quite good. Even in pink.
This is my standard camera test picture. I think it got the exposure around perfect.
Had both my flu and Covid jabs yesterday. Today both my arms feel like lead weights, but I still managed to take an old camera out for a walk and grab some shots.
Rob Miles is technology author and educator who spent many years as a lecturer in Computer Science at the University of Hull. He is also a Microsoft Developer Technologies MVP. He is into technology, teaching and photography. He is the author of the World Famous C# Yellow Book and almost as handsome as he thinks he is.
