Focus is important

I think I still might have a light leak…

It’s taken me a couple of goes to get this picture, taken on using my 3D printed camera. The first version was horribly blurred because I assumed that I could set the focus distance approximately and it would come out OK. This turned out not to be the case. The bigger the negative, the more important it is to get the focus right. The cameras uses film which is 4 inches by 5 inches, which is rather large. There’s a lot of detail there, but you only get it if the focus is correct.

Happy Birthday Me

It’s a lovely little device

It’s my birthday today. Yay! Above you can see my present to myself. It’s a Minox daylight developing tank. It lets me take film from my tiny spy camera and develop it without needing a darkroom. You put the film cassette inside the tank and the film is pulled out into the developing spiral. Then you add tiny amounts of developer and fixer and then you get your strip of developed negatives. At least, that’s the theory. I’m looking forward to trying it for real.

My birthday was great. Lots of cards and presents. And chocolates. And cake. Good times.

Computer Speedup trick - turn off iCloud Photo Sync

Start the icloud app and then clear all thse options for Photos

The title of the post says it all really. For a while I’ve been bothered by the way that the fan in my PC kept coming on when I wasn’t doing much. Then things seemed to slow down every now and then. A little detective work with Task Manager showed that the Apple iCloud Photo Sync process was grabbing 10% of my machine for no apparent reason. I’ve turned off photo sync. There’s no particular need for it on the PC and it has solved the problem.

I had a look at the Apple support for this problem and the suggested solution was to remove iCloud and install it again. Which wasn’t terribly impressive.

Achievement Unlocked: Rediscovered my Meccano Motor

I have no idea what I’m going to do with it.

When I was around 12 years old I got a Meccano motor for Christmas. Not just any motor. It had a six ratio gearbox and it came with tiny plugs that I could use to connect it to my Minic Motorways transformer. It was awesome. I made all kinds of remote controlled moving things with it. Then I lost it.

A few years I ran across the same motor in an antique centre in Beverley. After a few weeks of dithering about whether or not to buy it the motor then vanished from the shelf. Oh well. Then this week it (or one like it) appeared again. So I pounced. It’s in the original box and it looks as if it hasn’t been used. I’ve not fired it up yet. I’ve got plans involving MOSFETs and low speed control.

Mdns makes your embedded devices easy to find

I’m making a network controlled light. The idea is that the light hosts a web site which you can find with your phone or computer. The light will have an internet (IP) address which you can use to locate it on the network (something like 192.168.50.5) but this might change as these addresses are assigned by your network router on a first-come first-served basis. What you really want to be able to do is refer to your light as “flashlight.local”. The mdns service makes this possible.

I’m using Circuit Python to host the website in a Rasbperry Pi PICO-W. They have a lovely HTTP server library which works a treat. It also supports mdns (Multicast Domain Name Server). This lets applications (for example your browser) ask if anyone on the local network has a particular name (in this case flashlight.local). The mdns server running on the PICO-W responds to these requests with a network address which can then be used to contact the PICO-W. The code below was added to the application and starts the service running. This code is slightly different from the example code for the service, but it does work very well.

import mdns


mdns_server = mdns.Server(wifi.radio)
mdns_server.hostname = "flashlight"

Once the server has been started it seems to just run in the background responding to requests.

This is the final website for the light

You can use this to make your embedded devices much easier to locate. If they get given a different IP address next time they start up they will just keep going.

Cockroach Circuits

I’d say “don’t do this at home” but I’m doing it at my home so it must be OK…

I can just about fit a PICO inside my remote controlled flash light, but there is hardly any room for anything else. So I’m using the “dead cockroach” hardware construction style. The circuit looks like a dead cockroach with wires standing in for legs. The connections are created by soldered wire-wrap wire into the holes in the board. I’m going to wrap the whole thing in insulating tape before fitting it into the flash. I like using wire-wrap wire. It is so flexible that it doesn’t tend to come undone from connections. I’ve got lots of different colours, which makes it much easier to follow. The circuit above is an implementation of this:

My level converter is blue though…

The important thing to do is keep testing as you build it, although so far it has kept working .

Hurray for Level Converters

At its brightest this pixel gives out 3 watts which is a lot of light

I’m working on my PICO controlled flashlight. Today it was time to wire up the output led. I’m using a Pixie light. This needs 5 volt levels to control it, but the PICO only produces 3.3 volts. This might just work (some things do) but I’m a bit concerned that if the power voltage for the lights gets a bit too high the light will not work or worse, be unreliable.

So I’m adding a level converter. These are very cheap and easy to buy (search for “arduino level shifter” on your favourite ecommerce site), but a bit of a pain to wire up as you have to connect input and output signals as well as power supplies and grounds for each side of the connection. However, as you can see above, the light works fine. Next I have to work out how to get the circuitry into the flash gun.

Back to England

One of my purchases was a set of illuminated clothes pegs for hanging up photos. They seem to work

We had to come home today. Back to England. Nothing like going abroad to give you a perspective on where you live. England is a bit like France. But in black and white. Or should that be grey and white. Everything looks smaller, meaner, unhappier and less well cared for. It wasn’t always like this, but over the last few years we’ve been managed by people who are more concerned with meaningless ideological stupidity than making sure that the place (and the people) are looked after properly. Oh well. Hopefully things will change soon.

Flea Market Time

It was never explained why there is a flying saucer in the middle of the market

Another must visit place for us was the Paris Flea Market. Although of course we never saw anyone selling fleas. There was a lot of very interesting stuff though. From very high end custom made furniture all the way to jumble sale junk. In between you can find records, video games, photographs, toys, and mountains of stuff. We didn’t spot any bargains, but we did find a really good camera shop. And had a really splendid lunch (one of many we’ve enjoyed on this trip).

A quick guide to the French language

1. People really like it if you start with a “Bonjour”, rather than diving straight into what you want. And while they can probably speak pretty good English, trying some French is a good idea. I can know a bit of French, but I must be careful that I don’t use all of it at once when opening the conversation: “Bonjour, je m’appelle Rob. Je avec les yeux blu and est tres tall. Je’aime l’ordinator…”

2. For best results when asking for things, put a specific number in front of what you want. Rather saying “Can I have a coffee, and orange juice and a water” you should say “One coffee, one orange juice and so on.” The French for one is “un”. This makes it sound like you’re asking for the reverse of what you want – “Can I have un-coffee, un-orange juice and so on” but it does work a lot better.

3. Do not, not, not think that anyone will understand you better if you speak in a French accent and wave your arms about a lot.

Paris shopping and stuff

I’d been looking forward to going to Antiq-photo since we arrived in Paris. They have a huge selection of old cameras and stuff and their shop is as much museum as saleroom. Today was the day that we headed in their direction. Of course they were shut. Paris tip: open hours are not necessarily open hours. Next time I go I’ll call ahead and make sure there is somebody around. Although, it probably saved me a fortune.

You could hire a little sailboat to play with on the pond

We had a great walk thorough the Jardin du Luxemburg, spent the afternoon exploring the Palais de Justice (historical note - the French Revolution was not a fun time) and made our way back to the hotel for a splendid dinner. Then, refreshed, we headed out again to the Arc de Triomphe. We got there just as the sun was setting and it was a lovely place to be.

I had to risk my life to get this picture

Then it was back to the hotel, a quick drink and then bed.

Bastille Day

Making a flypast look easy..

Bastille day is a big thing in France. It celebrates an important moment in the French revolution. there were parades and an amazing flypast. We didn’t see all of it, not having got up at some horribly early hour to get the best place to watch. But what we saw was awesome.

It’s easy to look cool from the back of a horse..

Once we’d had our fill of the parade we got on the Metro and headed to an amazing Science Museum. This is in an enormous park. There’s a planetarium and a submarine, and we saw both.

I managed to explore the submarine without banging my head. Go me.

After dinner it was time to head up to the centre of Paris again for the fireworks display. Forty years ago I managed to watch the display from the Champ de mars right next to the tower. This time we were a bit further away, but the spectacle was no less impressive.

Not bad for an iphone picture..

I didn’t think that you could make a firework display last half an hour, but they managed it. And it was all wonderful. We were on Pont Neuf, one of the bridges over the Seine. We had a great view of the top of the tower. Any closer and it would have been much harder to see. After the display we wandered back to the Metro station and were back at the hotel in twenty five minutes. Great stuff.

Japan Expo

I have no idea who these people are

I’ve been to a few Comicon exhibitions in Birmingham. They are great fun. The Japan Expo in Paris is like Comicon but bigger. Much bigger. It was so big that it was much more fun to be at. Comicon at the NEC in Birmingham is nice, but later in the day it seems to “fill up” so that there is no room around the stalls and you can’t find anywhere to sit once you’ve bought a drink. Japan Expo is much bigger but the space available is enormous. Things got busy but nothing seemed to completely clog up. Also (and this is a tip for the NEC folks) the bins were kept empty and the toilets were always clean, which adds a lot. We bought a few bits and bobs and had a whale of a time. I really, and I mean really, want to go back next year if they have another one.

A guide to Paris waiters:

1. They are amazing. Fast moving, polite and they never write anything down.

2. They may have lots of tattoos. But usually only on one arm. This is so that they can stand sideways at the entrance to the restaurant and wave at you to come in without looking too scary.

3. They will always try to carry one more plate than you think is possible. And they will succeed.

4. They make everything a performance. In England you are usually given your knife, fork, and napkin as one rolled package that you have to unpick yourself. In France each item will be individually positioned in front of you. We had to try very hard not to say “merci” for each item of cutlery as it was laid down with a flourish. Drinks are served in a similarly complicated manner.

5. Whatever you choose from the menu tends to be their favourite too, which is lovely.

Popping to the Louvre

It gets a whole wall to itself..

Who’d want to have their art displayed in the galleries that are on the path to the Mona Lisa? Nobody, that’s who. Everyone zooms past just looking for the next sign to tell them the way to the most over-hyped piece of art in the world. We took a look (well – it is a thing) but we also gave other works on the way a look too. There was some lovely stuff on display. Pro Louvre tip: look up. The ceilings are incredible.

And to think that we just put two coats of White Silk emulsion on ours…

We didn’t see it all of course. Nobody could in one day. Or even a week. I’ve no idea how they keep track of all the stuff they’ve got. We took a peek at the “Venus de Milo” because it’s another must-see item. Historical note: to make some of the more interesting sculptures the artists used a technique called “green marble” where the bits that were a bit hard to do (like a man with the legs of a horse for example) where done in green marble and then replaced with the correct figure in post-production by another sculptor.

Start of the Sphinx Grand PriX

The Louvre also contains big chunks of Napoleon’s home life, including his bedroom and dining room.

You could set at opposite ends of the table and have a talk at great length…

I can just imagine them inviting their chums around for dinner and then sitting and chatting afterwards:

Guest 1: “Where are you going for your holidays this year Napoleon?
Napoleon: “I was thinking about Russia…”
(orchestra plays a minor chord)

After the Louvre we thought we’d go on to see the other end of the art experience by heading up to the Pompidou centre. To me modern art seems a lot easier to make. It doesn’t have to look like anything (one artist hit upon the clever wheeze of making the canvas exactly the same colour as the wall behind it). I may be a bit of a philistine (said the old man) but any art that needs to be explained to me is probably not art at all. Then again, I am a sucker for bright lights and pretty colours so that was plenty to keep us occupied. And we had a coffee there which was very nice.

Not sure what it is. But I like it

On the way back home we stopped off at Chatalet Les Halls. A big shopping centre which contains a Fnac (yay!) and also a Lego store. I headed for the Lego store and the pick and mix. I made a Lego picture years ago and the white pieces have aged really badly. I was overjoyed to discover that the pick and mix had a bunch of the ones that I wanted, so I filled a bag with these. In the process I also scattered fair few around the place – which I felt rather bad about. I was really pleased until I got back to the hotel and worked out that I’d actually bought a very large number of the wrong kind of piece. Oh well, I’ll find a use for them.

To the tower!

Nice Day for it

Last time I was in Paris for a holiday was around 40 years ago. Things have changed a bit. The tower is now “fortress Eiffel”. In earlier, simpler, times you could just wander underneath the tower and find the entrances to the lifts or stairs to the top. Now there is an inevitable bag scan and a high fence all around the monument. And rather than just “going up the tower” we have the Eiffel experience. Where you go up the tower and have a plastic glass of champagne. It was very nice though.

If I’d been here a little earlier the Eiffel Tower shadow would have lined up exactly with the road….

For lunch we wandered over to the Printemps store. I’ve got very fond (and probably faulty) memories of a huge open cafeteria at the top of the store with cheap basic food and huge views. This is, of course, now also an “experience”– with prices to match. There were various different eating options (we went for pizza) and the views were as good, but I feel they’ve lost something of Paris here.

Travel tip: There are a few discount tickets for the Metro but the best value one requires you to add a photo ID to the card. You can pay 8 euros for a photo-booth, but you can also use black and white pictures that you can get from a Kiddizoom camera that you might have taken with you. This seemed to work a treat, although nobody ever actually asked to see them.

We spent a while in Fnac. It’s a lovely store. There are quite a few around Paris. They are a cross between a bookshop, game shop, camera shop, audio shop, computer shop and video shop. All very well done with keen prices. And busy too. Hopefully they can stay in business.

After lunch we had a wander back to the hotel, picking up a splendid meal on the way from one of the many restaurants they have around here. I really like Paris.

Heading to Paris

The train did get a lot more busy as we got close to London

We’re having a week away in Paris. We’ve been planning it for months. And that’s just choosing which camera to take. We’re going by train and using the tunnel. This is a bit more expensive than flying (which seems all kinds of wrong to me) but means we arrive right in the middle of Paris and the hotel is a short walk from the station. Pro tip: Hull Trains are lovely but they don’t have any on-board catering. Take any snacks you want to eat with you. The good news is that the journey is now shorter than I remember though.

Not a bad place to be

All the train connections worked, the walk the the hotel was easy and we ended up in the hotel garden sipping well deserved (we thought) beers. The fun starts tomorrow with a trip up the Eiffel Tower.

Ready to travel

Heading out on holiday soon. Spent ages putting cameras and lenses into a bag. Then a a few minutes lobbing clothes into a case…

From HSB to RGB with ChatGPT

Next I need to add some style to the page

Yesterday I was building the web page used to set the colour of my remote controlled light. At first I went with three sliders to set the amount of red, green and blue (RGB) in the required colour. Then I decided that it might be use Hue, Saturation and Brightness (HSB) as a way of setting the colour. RGB is great, but if you want to change the overall brightness of a light it is a bit of a pain because you have to adjust all three sliders. This is much easier with HSB because you can adjust the brightness directly.

Adding the three new sliders to the web page was easy, but then I was faced with the problem of converting RGB to HSB and back. I wanted the display to be updated so that if you change the Hue the settings of the RGB values change to keep track. So I needed some conversion functions. I thought I’d ask ChatGPT to lend a hand. This is how I would expect the tool to be used. You’ve got a strong idea of what you want to do, experience with the tools and techniques you’re using and you just want the code.

ChatGPT was very happy to drop out JavaScript that it said would work. But it didn’t. Turns out that both Blue and Brightness begin with B. So all the single letter variables in the functions clashed with the parameters. I explained this problem and ChatGPT then dropped out some code that worked.

For me the interesting about this was that I found ChatGPT useful, but I needed to add my programming smarts to solve problems in the code that it produced. This gives me a tiny bit of hope for the future. It doesn’t look like I’m going to be completely replaced by ChatCPT. At least for now…

MVP Renewed - with Parrot

I’ve been waiting for ages for a reason to get this…

Very pleased to be able to report that I’ve been renewed as an MVP for another year. That makes it 20 years. I’ve spent nearly a third of my life as an MVP! Thanks very much Microsoft.

I got my self a parrot kit to celebrate. As you do.

Remote Controlled Lights Working

This is the prototype light display

I’ve got the code for the remote controlled flash light just about working. It turns out to be a fairly simple matter to get a web site host running on a PICO and then get it to respond to incoming requests.

This is the interface to set the colour of the lights

I’m waiting for my super-bright led to arrive and then I’ll get the hardware built. Great fun. I’ll put all the code and designs onto GitHub when its finished.

Harrogate is wonderful

We could have done with some clouds to make the sky more interesting..

Harrogate is a wonderful place. Not just because of Bettys, or the fantastic game shop but because of the amazing park that runs alongside the town. It has everything you might want for fun, especially if you are six years and six months old (or thereabouts). There’s a zipwire, crazy golf and somewhere that sells ice creams. Plus a padding pool if you’re feeling brave and have a towel with you. We had a very happy time there today. And we’ll be back.

There are a lot of different makes of trees in this picture