So - we've insulated the sleeping room (originally a garden cushion box) for the rabbits and mounted a heating panel that should keep it between 12˚C and 15˚C. But we need to keep an eye on it.

I could just get a cheap thermometer with remote unit from a hardware store - but how to check how the temperature varies over time?

Let's play with an arduino instead :)

I started with this tutorial from raywenderlich.com. It's using OneWire temperature sensors called DS18B20. I'm also going to use an ethernet connection with PoE to avoid having to have a separate power supply to the board.

I also modified the code by grabbing the latest onewire and dallas libraries and changed the output from JSON to a format that it is easy to write a munin script around.

The circuit I have ended up with is:

And breadboarded for testing it looks like:

Components

Code

It's all on github