In search of ancient files...


It turns out that my original C programming notes are coming back into fashion. Thanks to the archiving efforts of a site in China (thanks foks) I’ve managed to get hold of the PDF of the notes, but I can’t find the 25 year old original of the document. I’ve spent a big chunk of today turning on ancient laptops and finding that their disks don’t go round any more, including this one above. I think the platter has kind of stuck. Or something. I’m tempted to open it up and give it a tiny twirl. After all, it can’t make things worse……

Good Friday Sounds

Number one son has been buying vinyl. Just like I was doing forty years ago. In celebration we got his B&O system down from the loft and fired it up. It used to be my dad’s pride and joy, and it was wonderful to hear it back in action. The word was that if it didn’t go bang when we powered it up it would probably work fine. And it did. There’s something about proper analogue sound that I really like. Perhaps I’ll get my deck (and all the records) down and have a go some time.

ESP32 powered webcam for 7 pounds


In my fingers above you can see something rather amazing. It’s an ESP32 powered webcam and it is priced at a stupidly low level. Mine arrived earlier this week and I’ve found a splendid howto that gets you started. You’ll need a serial interface to program the camera as it doesn’t have a usb connection. I used the one I got with some Arduino Pro-minis a while back. A couple of tips:

  • make sure you update to the latest version of the ESP32 board. The older camera sample will not compile.

  • the device can be a bit picky about power supplies. Mine gave “brownout” warnings for a while before I connected the 5V input to a slightly beefier supply than the 3.3V I used to program it

The camera serves up a website with a wealth of controls that you can use to change the image quality. You can use it to grab stills or watch a video stream. It even supports facial recognition and it has a micro-SD slot for saving stuff to. Amazing.


For the price you really should get one of these and have a play. I’ve been looking for a quick way to get pictures into Azure for training image recognition. I think I may have just found it.

GitHub Two Factor Authentication with Microsoft Authenticator

Microsoft Authenticator.PNG

I’ve just turned on Two Factor Authentication for GitHub. It occurred to me that seeing as how GitHub is now my “weapon of choice” for organising anything, and I can make my own private repositories, I should take some steps to keep them private.

It’s actually very easy to do, once you have an app that can produce “Time Based On Time passwords” or TOTPS. I’m using Microsoft Authenticator. I figure that since Microsoft now own GitHub, it’s likely that Authenticator will work well with it.

Making bendy pipes with FreeCAD


Achievement unlocked. I now know how to make “bendy” things in FreeCAD. It’s actually not that hard once you work out what FreeCAD needs to know. Essentially you use one Sketch to define the path of the template and another (which should be at right angles to the path) to define the closed shape to be created. You can even add another closed shape at the end of the path and then have the shape smoothly change from one to the other. I’ve used this to create tapered tubes.

I’m doing this to make another Air Quality sensor. I want to send the air path round a curve that is too tight for pipe. I also want to add a “u-bend” so that it is harder for water to get into the sensor. I’m quite pleased with the above. Now I just have to figure out how to mount it in the case….

Crippled Hexabot

Ages ago (well, four years) I made a hexabot from a kit. Today I thought I’d get him out with a view of adding some sensors and an ESP32 to make him a bit more autonomous. He was a bit lame. Two of his servos had stopped moving. Fortunately I had some spares and so I set about getting him walking again.

It didn’t go well. I broke a replacement servo finding its mid point and fitted the second one upside down. Twice. I think that a few hours of gardening has destroyed my ability to work with electronics.

However, I think he is now back to his sprightly best. I’ve ordered a camera pan and tilt (around 3.50 with servos) and a distance sensor with pan mechanism (also around 3.50) from AliExpress. Looking forward to them arriving.


I’m not that keen on gardening. It seems to me that you can spend ages making the garden look nice and then, only a few years later, you have to do it all again.

Sometimes it’s more frequent than that.

The latest re-modelling involves the removal of stuff. I’m quite good at this, although I’m a bit of a blunt instrument and I’ve been known to generate a lot of “collateral damage”. Today I was carefully programmed with the items to destroy and left to it.

Pro tip: If you are removing something substantial from your garden, don’t cut it down to ground level before trying to dig out the roots. Leave a nice long stalk to use as a “handle” to give you some leverage on the stump. I did this, but the person who’d chopped down a whole bunch stuff before me hadn’t. As a result I had a happy five hours digging round the tiny bits left, chopping and sawing roots and using appropriate language.

I’ll tell you one thing though, if you think I’ve had a bad day, the objects of my attention had a much, much, worse one…………

If you've got Netflix, watch RIPD


RIPD is the kind of film that you might like to watch after a hard day writing and editing course notes. It’s nice, mindless fun. If you took the scripts of “Men in Black”, “Ghost” and “Ghostbusters” and put them in a blender you’d get the script for RIPD. In fact that might be how they did it.Then again, they may just have decided that the name RIPD (Rest In Peace Department) was awesome and written the entire film from that.

Either way, it doesn’t take the caper comedy film anywhere particularly new, but it’s still worth going there.

Back Lit Tracing Screen


I’ve been taking pictures of devices for a course that I’m writing. I’ve been fretting about the way that it is hard to avoid shadows underneath components and wires. I wondered if a tracing screen would be any good at eliminating dark areas on the background. You can pick them up for not much money nowadays, so I bought one.

It’s not quite what I want, as you can see above the light is a lot of points rather than even. I’m trying to find a diffusor that give a nice even spread. However, this does mean that if I ever want to trace some pictures I’ve now got the perfect device.

Go and see Shazam!


Perhaps the secret of a happy life is well-managed expectations. Anyhoo, my expectations of Shazam! were not that high. We’d been to see Captain Marvel a while back and marvelled (no pun intended) at the ease with which the Marvel empire seems to be able to turn out pitch perfect superhero movies whereas those from the rival DC stable seem to be much harder work.

However, Shazam! was really good fun. Not afraid to send itself up, but proper wholesome fun with a strong family theme. The story was very much by the numbers, but the realisation and some of the lines, along with the performances of the central characters, made for a thoroughly enjoyable experience.

Slack is not your friend

I use Slack quite a lot on various projects. I quite like it (even though I have real difficultly understanding how a such a simple program can take around half a gigabyte of memory to run). However, one thing that really irritates me is the way that every now and then it pops up a trite aphorism (something like “Don’t forget to breathe”) with the byline “Your friends at Slack”.

Every time I see this I think two things. I wonder just how much of my precious memory is being used to generate these messages and I reflect that I’ve never met anyone from Slack and I have no way of knowing if they are my friends or not.

Oh, and the other thing about Slack that irritates me is that it seems to be impossible to kill. I’ve had screencasts interrupted by Slack pop-ups even when I’ve disabled them and even quit the Slack application. It seems to me that the only way you can get a Slack free life is to stop it from running when your machine boots.

Being polite pays off

I’ve started saying please to my electronic devices. This is not because I’m super-polite (although I like to think I am). My reasoning is that if you put “please” on the end of a request the device can tell that you’ve finished your command, and that it needs to go off and work out what it means and then do it.

From my completely unscientific testing I’ve found that it does slightly improve accuracy and response. Which is nice. I might start saying thank-you next.

Amazon Echo buttons are surprisingly easy to use


You might thing it’s surprising that I’m this late to the home automation party. What with my love of gadgets and all. I guess laziness trumps gadget love in the end.

However, a few weeks ago, on the back of a really tempting Amazon offer, I got myself a batch of Teckin smart sockets. They fit into your mains socket and then you plug the device to be controlled into them. And then the device is connected to the internets.

A socket can switch up to 15 amps (it says) although I’ve not tried one with the kettle just yet. The only snag with them is that they are slightly larger than a normal mains plug which means that they tend to foul the switch on a wall socket. This is not a problem for me. I’m plugging them into distribution boards, but you might find it irritating.

They work well, once you get over the fact that the lights in your house are now being controlled by a server in China. You can control them from your phone, put them into groups so that they can all be switched at the same time and even see how much current a particular socket is drawing.

So, in no time at all I was in business. Rather than flicking an old style switch I could just get out my phone, unlock it, find the application, navigate to the required group and then tap on the screen. Much simpler. Really. Actually, that’s why I’ve been a bit late to home automation. It actually doesn’t seem to make things that much better.

I made life a bit easier by connecting them to my Amazon Echo device. So now I can just ask Alexa to turn the lights on and that works fine. But what I really want is a button that I can press to turn the lights on. And finally, I’ve got that. Amazon now makes Echo buttons. These were originally touted as a fun way of playing games with Alexa. They are not to be confused with Amazon Dash buttons, which are being discontinued.

I picked up a couple of buttons and they are nicely made, robust devices that connect to your Amazon Echo via Bluetooth. I had a go at the games and I wasn’t that impressed. They gameplay was pretty uninspiring and there was a lot of lag between actions and responses. But you can also use an Echo button as a trigger for a routine. So I’ve made a routine that turns on the lights and bound the button to that routine. It’s very easy to do, you can do it on your phone. The only snag is that there is no way of “toggling” the state of something via a skill. So I’ve had to use two buttons, one for on and one for off. If I write my own skill I can probably get around that, but for now I’m happy and a bit closer to the cutting edge than I was.