Building an Air Quality Sensor

I've been having proper fun today. I started with one of my tiny Heltec embedded controllers and an urge to connect it to an air quality sensor and a temperature/air pressure/humidity sensor. 

It wasn't easy, but it was possible. Biggest problem was that the temperature sensor uses an i2c connection to the Heltec device, and so does the lovely little OLED panel that you can see above showing numbers.

Turns out the way to make it work is to create another Wire instance and then use that for the temperature sensor. Anyhoo, it works. If you want to see the code you can find it here.

I've written everything using message pumps and state machines so that it should be possible to have all this working together without something getting stuck.