Amazing AI Enabled Camera

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This is an amazing device. A while back I had some fun with a very impressive AI enabled camera which is very neat, and around 60 quid. I’ve just got one another AI enabled camera which is a mere 17 dollars. You can program in in Python straight from your PC over a USB port. It exposes a GPIO port that you can use to send commands to another device.

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The SDK is a free download and M5stack (who make the device) even seem to have some help for you creating your models and training them. And it has holes in the back that let you fit the camera on Lego models. This is completely awesome.

M5 Atom is absolutely tiny

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A new computer arrived at our house today. The postman just popped it through the letterbox. The Atom is a tiny new microcontroller from M5Stack. It contains a button, a multicolour led and an accelerometer. It has enough pins to be useful along with a Grove socket.

It’s a little bit bigger than the top of my thumb, it contains an ESP32, it can run MicroPython and hang off Azure or Bluetooth. And you can buy them for six dollars apiece.

I know that the world today is a right old mess, but there are still some amazing things to be found.

USB Power Supply

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This is a really useful device. You feed it power from a USB socket and it puts out a range of voltages from around 14 volts down to two or three. You can also set it to limit the current supplied and it has a nifty display of current and voltage. Great for testing simple circuits and well worth the price.

I got mine here and the customer service was excellent. My first device arrived with the perpsex covers smashed. I messaged the supplier asking if they could supply a couple of spare covers as the electronics worked fine, but they sent me a complete replacement. Good product and good service. Thanks for that.

Note: One thing to be aware of is that the device arrives with the output voltage set to maximum. Make sure that you adjust this down to your required voltage before you plug it into the device you want to power with it.

I've made a cube

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It looks like I’ve made a cube. Although it occurs to me that I could have just joined three squares together, since you’ve no way of seeing the back from this photograph. After a week or so of pretty solid 3D printing and assembly I have learnt two things:

  • it looks really cool

  • it’s very hard to photograph

I was going to make it into a totally portable cube that could be passed around. However, I’m re-thinking this for a number of reasons:

  • it will be rather hard to fit all the electronics and the battery into the cube interior

  • the battery life will not be that great

  • somebody might drop it

So, I’m thinking of just mounting the cube on a plinth and turning it into a rather cool light.

Update: Change of plan (as if you care). Anyhoo, I’m going to make the full fat, chuckable cube and then fashion a base which I can use to turn it into a lamp.

Tiny Sony Speaker

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I picked up this tiny Sony speaker today in HMV in Hull for not much cash (even less than Amazon are selling it for). I’ve been looking for something to use with small musical instruments and this looked like it might fit the bill. It has Bluetooth connectivity and even contains a tiny microphone so that you can use it for handsfree phone calls. However, it also as a 3.5mm jack socket that you can use to connect any audio source that you fancy. It’s battery powered and also waterproof (as long as you remember to put in the rubber plug that seals the connectors.

The sound is much nicer than you would expect from such a tiny device. I wasn’t expecting floor shaking bass, but what is there is very clear. And the rest of the frequency range is very well catered for as well.

If you are looking for a slightly beefier sound than you get from your phone it is well worth a look.

Playstation Controller Back Buttons

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Number one son is in town for the weekend. We went shopping today and he bought something rather interesting. Back buttons for the PlayStation 4 controller. They are a nifty moulding that fits underneath between the controller sides. By cunning use of a moving plug they wrap themselves around to make it look as if they are part of the controller. They provide two extra buttons that are really easy to press with those fingers that normally wrap around the controller to hold it. They are configured using a tiny OLED screen and a single button. You can get them to produce a button press that is mapped onto any of the other controls.

For example, you might replace things that are rather hard to do, like pressing in the thumbsticks, with rear button presses. And some actions, for example change up and down the gears in a driving game, are crying out to be put onto controls like these.

They work with all existing games because as far as the game is concerned there is nothing new happening. The game is getting the control inputs it is expecting, but they are being triggered in a different way.

I’ve been told (quite rightly) that I don’t play games at the stratospheric level for such add-ons to really pay off for me, but if you want to do things like shoot when jumping or easily change gears, they are worth a look. Apparently in the UK they are being sold exclusively by Game.

Python Ruler

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I now have a ruler that will run Python. My life is complete……

Actually it is quite useful. Probably. You can program it to show up as a keyboard device and you can get your program generate keypresses when you touch the panels. The default settings are as shown above, but I’m going to make it generate the backslash character which I always have difficultly finding thanks to my liking for American keyboards.

It runs Circuit Python which means that you can just drop your code into the usb drive it mounts when connected. The only thing I don’t like is that you have to plug the ruler into an external power supply to get it to work. If it had a little battery it would be perfect.

Bye Bye HiFi Walker

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I’m not having much luck with my high resolution music players. My first one, a Sony, decided to destroy its battery (and then destroy the replacement battery that I bought) by shorting it out. I suspect the charging circuitry. That went to the tip. And now my second, which had the wonderful name “HiFi Walker” has had the display fail. So, despite there being no obvious way in, today I tried to fix it. I was hoping that upon the removal of the back I’d see a dangling socket I could just reconnect to tumultuous applause.

Unfortunately that’s not how it has worked out. After using the hair dryer to loosen the glue I got the back off to find a perfectly assembled circuit board with no obvious flaws. So it was time to double down and remove the processor board completely from the case and check the display connections. Which of course all looked fine to me, even though the display was obviously still broken.

This is the a genuine “blue screen of death” in that it is all that is displayed. Oh well. At least I tried.

Measuring Power Consumption

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You may be wondering how I can be so sure about the power consumption of my various devices, what with the amounts being so tiny. Well, I’m using one of these. It is supposed to be used for testing batteries and power supplies, but it gives a rather useful four digits of power consumption information. I’ve made up a special connector from an old USB cable and I’m getting depressingly accurate readings.

In case you are wondering about the device at the top, that is something you can use to apply a hefty load to a USB power source. If you do decide to use it, remember that the resistors (the two green things) will get very hot.

Old game boys never die

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There must be about twenty quid’s worth of stuff here….

A couple of weeks ago we went to Comic Con in Birmingham. As I remarked at the time, | didn’t buy much. One of the reasons was that I already had lots of things for sale on some of the stalls. Today I happened across a bag full of bits and bobs, including my beloved Game boy Color and printer. Amazingly it still had some of the pictures in the camera memory. The printer still works too, although the thermal paper seems to have given up the ghost. I wonder if you can still get paper for it?

Broken Mindstorms

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I thought I’d have a play with my Lego Mindstorms Rubik Cube solver. But the controller is broken. I’ve tried everything. I’ve put in some new batteries, then another set in case the new ones were broken.

I’ve even taken the back off and had a look inside (always guaranteed to fix anything I find). It’s really complicated in there, and beautifully made.

But it doesn’t work.

Oh well. I’ll have to solve the cube myself…

A bit of fun from a tiny game

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I was in Ryman’s in Hull today looking for cheap AA batteries (I have lot of robots to feed) and I came across a tiny handheld video game that had been massively reduced in price. Always a sign of quality I find.

However, the promise of 150 games for a tenner was too hard to resist. So I invested in one. Note that I never say “bought”, always “invested in”. Buying something means that the money is gone for ever, whereas an investment has the potential to go up in value over time. Although I think that it is unlikely in this case.

Anyhoo, the game is not bad. The hardware works well and the screen is bright and clear. There are indeed 150 games. I was expecting a bunch of dodgy ports of old 8 bit favourites but the reality is a bit different. It’s rather like someone has locked a programmer in a room and said “You can come out after you’ve written 150 games”. The range of gameplay types is interesting. They are all very casual. None have any instructions and so for me a lot of the fun comes from figuring out just what your are supposed to do. And if you get bored or irritated by one you just move on to another. I’ve had quite a bit of fun with this already and I think I’ve recovered my investment.

TTGO Camera

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A while back I ordered a TTGO camera from Ali Express. It came today and it is lovely. It is similar to the ESP32 webcam that I bought a while back, but it has a PIR sensor and a BME 280 environmental sensor along with a nifty OLED display.

It is supplied with firmware that sets it up as an Access Point. If you connect to it you can view the image and control it from the web page that it serves out. I think it is running the same software as I loaded into the earlier device, but it is nice to have it on the device at the end.

It works extremely well. I’ve printed a little case for it from a design I found on Thingiverse and now I’m looking forward to having a play. They say it can do facial recognition, which is very interesting, and it might be a good device for our Humber Care Tech Challenge entry.

Update: I’ve found a nice blog post here on how to use this device as a fridge alarm. This shows how to put the processor to sleep and trigger wakeup using the PIR sensor.

Getting Started with Micro Python on ESP32

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I got my little game working on the Raspberry Pi yesterday, and today I got to thinking how I could make it work on something a bit, er, cheaper. It’s not so much that I begrudge paying the price for the Pi, more that I can think of more demanding things to do with the Pi than just run the game. My thoughts turned to the ultra-cheap ESP32 devices that I’ve been playing with. The only snag is that I’ve written the entire game in Python for the Raspberry Pi, and I don’t fancy re-writing it in the C++ that these devices normally run.

So, why not run Pyhon on an ESP 32 device?

This turns out to be really easy. If you’ve installed ESP32 devices as part of your Arduino development environment you will have a useful little program called esptool.py on your machine. To convert a device to Micro Python you just have to plug in one of those ultra-cheap devices, find out what serial port it is connected to (in my case com4) and then use the command below to program the chip with Micro Python.

esptool.py --chip esp32 --port com4 --baud 460800 write_flash -z 0x1000 micropython.bin

This loads the image in the file micropython.bin into the device. To get a Python image, go to the download site and look for ESP32 devices. I used the one in the file esp32-20190714-v1.11-146-g154062d9c.bin

Above you can see what happened when I ran the command.

When you restart your ESP32 you will be able to talk Python to it via a command prompt. That’s fine, but what you really want is an IDE that lets you write and deploy Python programs.

The best one I’ve found is called Thonny. It’s works with “normal” Python nicely enough, but it also has an option you can use to point it at an embedded device:

In the options menu above I’ve told Thonny to search for a device running MicroPython and connect to that. Now, when I run a program it is deployed into the device and executes from there.

The MicroPython installation provides a tiny filesystem that can hold python programs. When you run a program it is transferred into that filesystem and runs from there. There are two special program files on the device, boot.py and main.py. The program in the boot.py file is executed when the device powers up, followed by the one in main.py The Thonny program has an option (in the Device menu) to save the program you are editing one of these files. This makes it really easy to make your Python program run when the device is powered up. I made my game program the main.py one and now I have my original Python program running inside a device that only cost around a fiver.

It wasn’t quite as simple as just copying the files over. The api (application programmer interface) to use GPIO ports and Neopixels are different in the two devices and I discovered that MicroPython does not provide a random.shuffle method. This meant that I had to create my own shuffling function, which wasn’t too hard.

Anyhoo, I now have my program running in Python on a tiny embedded device. Which is rather nice. I’ll put the code up on GitHub later this week.

ESP32 powered webcam for 7 pounds

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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.

Back Lit Tracing Screen

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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.

Music to arrive to

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I’ve been thinking about satnav systems and music players and I’ve decided that what would be really wonderful is a system which linked your navigation and your car music system together so that the currently playing track ends just as you turn into your drive at home.

This might be a bit tricky to arrange, but in theory the satnav knows when you’re going to arrive and could tell the music player to pick appropriate length tracks as you approach your destination.

I’m suggesting this because on the rare occasions when it happens to me I think it’s awesome. I’ve even been known to speed up or slow down slightly to make sure that it happens.