Step 5: But what does it do????
I have these boards strewn all around Mikals house - they are doing things ranging from measuring temperature, to measuring humidity, to controlling the temperature of the beer fridge.
Here is a photo of one of them in situ - in this case it is measuring the humidity near Mikal's books. This is an old version of the board - but it has been doing sterling service.
If you want a copy of Mikals code from any of his systems, check out Mikals blog at http://www.stillhq.com
The old version of the Beer controller is at: http://www.stillhq.com/arduino/000003.html
and the Hygrometer is at: http://www.stillhq.com/arduino/000007.html