I was wondering
has anyone yet replaced his home thermostate with a arduno.
Just only the thermostate and hacked his way in into his heating system .
I was thinking that one could make a thermostate, and use temperature reading
And light and sound, to detect if someone is home, and made his own scheme on how you want the temperatures to rise, during a week.
Perhaps even put the whole program in a attiny 2313 and operate it on a lower voltage (so you could keep the arduino to play with) ?.
I have as well. Just heating although the arduino does a lot besides. The arduino can autonomously maintain a temperature, a small server (a hacked NAS box) keeps score, draws pretty graphs and tells the arduino what temperature to maintain at whatever time of day/week. It can be overridden via the server's web site.