Drink Manager Diagram Maker

/

If you want to create quick little diagrams like the one above I can strongly recommend PlantUML. Below is the text description that I wrote for the diagram above. 

@startuml
title RFID Reader Device Operation

start

:RFID Card ID received;

:Check if Card ID Exists in Internal List;

if (Card Found?) then (Yes)
    :Turn on RED Light;
else (No)
    :Turn on GREEN Light;
    :Add Card ID to Internal List;
endif

stop

@enduml

PlantUML can create all kinds of diagrams. It is free to use online (although the popup adverts are really annoying) but you can also install a local copy.

Get rid of wavy red lines

/

Note the lack of wavy red lines

I’ve made a tiny change to the Simpleterm page. Simpleterm is a tiny serial communications program that lets you plug a Connected Little Box into your PC or laptop and then configure the box via the serial connection. Normally text display boxes (like the ones used to display output form the connected little box) perform spell checking on their contents. This can be annoying. Lots of the elements in the screenshot above are correct but not properly spelt words and so end up with wavy red lines underneath them.

The fix for this is easy. You just have to add “spellcheck=false” (without the quotes) to the HTML element. I’d much prefer it if spell checking was something you enabled, but we are where we are.

Hardware Meetup Time

/

I took this picture yesterday

I never seem to have any pictures of the really good meetups. We are all too busy talking about this and that and solving the problems of the world. Today was no exception, greatly enlivened by the arrival of Simon, a splendid fellow with an appreciation of time technology. He and number one son (a budding clock builder) had a great conversation about topics such as escapements and whatnot.

Ross brought along his piano keyboard reading technology which is now in full-blown PCB form and looks really lovely and works well. And we rounded off the evening with some great Italian food from a restaurant I didn’t know existed.

The next Hardware Meetup will be on the 22nd of January 2025. It's going to be a big one, with a musical twist. If you want to know more, ping an email to hardware@robmiles.com and I’ll add you to the mailing list.

A little more agitation...

/

It was a lovely clear day

Went up town today (lunch at Thieving Harry’s) and I took a few pictures. Then, when we got back I developed the roll. When you develop film it is a good idea to move the film around a bit (although you can also leave it standing for an hour or so). Up until recently I’ve been turning the tank upside down a couple of times for each minute. This works OK, but if the tank top is not entirely watertight you can end up with hands full of developer.

So lately I’ve tried using the little “spinny thing” that came with the tank and lets you rotate the spiral containing the film. This is easier to do and keeps your hands dry. It also doesn’t agitate the film as well. If you look at the picture above you will see streaky marks in the sky which I think are caused by insufficient agitation. It looks like I’m going to have to go back to “wet hands” process. But I think I’ll get some gloves too.

Yet another camera

/

yes. I do need a haircut

Up early and over the Humber Bridge today to pick up another camera I seem to have bought. One of the factors driving the purchase was that I would be able to go down and pick up the camera from the seller, who turned out to be a splendid fellow. I planned to take a few pictures of the Humber Bridge on the way back but the weather had other ideas, so I had to resort to indoor shots to give the camera a workout. Including the traditional self portrait.

I also took a shelf portrait too……

Enter the blind man

/

We had a blind man come to see us today. Which sounds a bit like a contradiction in terms, but actually he was hanging some vertical blinds. Up until now I’ve hung all the binds in the house myself but this time I thought I’d let someone else take the strain and responsibility of drilling three holes in a line and then fitting some clips into them. The good news is that all went well, although apparently I’ve been hanging blinds in the wrong way for the last twenty years. Oh well.

Free Cameras

/

The chap in the Camera Shop in Beverley knows me quite well. I think I might be his pension plan. Anyhoo, he has now taken to keeping old cameras behind the counter that he thinks I might find interesting. And, even nicer, he hands them over for free. Today I was the happy recipient of three such cameras. Two of them were Kodak Brownies which are nice enough, but use 127 sized film which is no longer made. So they are useless for taking pictures.

The third camera was a different proposition though. It is a “Kodak Folding Hawkeye”. It has bellows in good condition, a clean lens, a shutter that clicks with encouraging noises and, best of all, it takes 120 roll film which is still sold today. At some point I’ll pop a film in it and see what it can do.

Rob's Ten Minute Rule

/

I’ve invented “Rob’s Ten Minute Rule”. It goes like this: “It is often worth spending ten minutes on something that you are not sure about”. In ten minutes of searching and chatting with ChatGPT you can usually find out if something is a good idea or not. If it looks promising you can spend another ten minutes (or maybe even more) pursuing it. If it doesn’t work you walk away from the idea only having lost ten minutes of your life.

LittleFS filename conventions

/

LittleFS is a great way to store files on your PICO or ESP powered embedded system. But it does have its foibles. Particularly when you switch from one platform to another. One thing that can trip you up is that on the ESP8266 and the PICO LittleFS the name method provided by a file object delivers the name of the file in the folder(test) but on the ESP32 LittleFS it delivers the file path to the file (\start\test).

I just discovered this while migrating the Connected Little Box code to the PICO. I’m putting this here so that I can find it again when I hit the same problem in a couple of years time.

PICO Probe in PlatformIO

/

I probably shouldn’t be quite so surprised when something just works, but I must admit to being slightly shocked when I managed to deploy a C++ application into a PICO using the Raspberry Pi debug probe the first time I tried.

Debugging just works too. I’ve now got a new PC (replacing my 8 year old one with something a bit more sprightly) and the build and deploy cycle is now pleasingly short. This really is a great way to work. I’ve now got the Connected Little Boxes core running on a PICO as well as ESP32 and ESP8266 and I’ve re-factored the code so that it is now easy to manage the feature set assembled into the code. This makes it much easier to remove features that won’t fit on the ESP8266. Great fun.

Farewell Mike

/

A sad day today. I went to the funeral of Mike Brayshaw. I worked with Mike for quite a few years. He was a wonderful fellow who wore his deep knowledge very lightly and worked tirelessly to educate and support students and the university. I’ve got great memories of loading Raspberry Pi devices into his car and driving off to a conference. There is a lovely in-memorium here.

Farewell Mike, a great person taken far too soon.

The Boiler Detective

/

This is almost exactly how it looked

On Monday mornings our boiler stops working. How does it know? Has it been programmed to make the worst day of the week a little bit worse by making the house cold? I’ve tried asking for help with it, but once reset it seems to come back to life. The fault code is as enigmatic as the sphinx. And it is hard to mend something that isn’t broken. The worst kind of bug.

Anyhoo, I’ve figured it out. It turns out that Sunday night in our house is also “have a soak in the bath” night. The rest of the week we have speedy showers, but on Sunday a hot tub is in order. And the bathtub and the boiler share the same downpipe. When the bath is emptied the huge surge of water overwhelms the pipe and causes the to back up into the condensation drain for the boiler. The boiler doesn’t like this, and shuts down. And we wake up cold on Monday morning.

I’m going to get the plumbing looked at when the boiler is serviced. We are still going to have baths, but I’m tempted to 3D print a flow limiter to put in the plug hole so that the bath drains more slowly.