Background
A Raspberry Pi is a lovely little single board computer, running the Raspbian flavour of Linux. They are cheap and with a bit of sysadmin knowledge easy to use - I have a half dozen already, I get them onto my wifi while connected to keyboard and monitor, and then disconnect everything but power and SSH into them to play with them. They run Python which is lovely; and there’s quite the ecosystem of components, sensors and add-ons to play with.
Projects
Weather bot
Here we have a Pi Zero with a SenseHat attached - just for the LED grid, I’m not using any of the other sensors, mostly because the temperature one doesn’t read at all accurately. It polls OpenWeatherMap every hour, downloading the forecast for Auckland and displaying daily forecasts and rain predictions for the coming week. It seems to work pretty well - the forecasts change quite frequently, but seem to be accurate once they arrive.
Lifx tiles
Lifx tiles are programmable LED tiles. Bought 5 of them, attached them to a board, and hooked up a Pi with a range of display modules - shares, weather, Conway’s Life etc - cycling through them. They’re … OK, the display is intentionally blurry so some of the info is hard to read, and the animation running off a Pi is clunky.
Digital photo frame
Got it working, but the screen isn’t brilliant, and I haven’t get figured out how to get it properly full screen.
Metriful - environment sensors
Metriful is a successful kickstarter program to provide a small but but useful set of Pi-compatibly environment sensors. It plugs pretty much straight in, and works as advertised.
I set it up to upload it’s data to TagoIO, a very nice little IoT data / graph platform with a good free account.
Morse news
I’ve been wanting to learn Morse for some time.
This tiny app will reboot at 6am daily, and make a single call to NewsAPI : https://newsapi.org/docs/endpoints/top-headlines
It will then loop over the titles of the articles for that day, and blink a little red LED; giving me the chance in less-inspiring meetings to practice reading Morse.
There’s quite a few things I want to do with notifications like this. And yes, the inspiration is from Cryptonomicon.
Meters
An idea in the pub turned into this : a series of Raspberry Pis pretending to be electricity meters, uploading usage data to a meter data management system.
This gave me the chance to try a couple of Picos for the first time. There were a few challenges - it’s quite a different approach, essentially running a single Python script rather than having a proper computer (so the script has to connect to a wifi network and set the correct time); and MicroPython != Python. But I got them working.
A full writeup, with more pictures on Github