While I was waiting on boards and parts I started assembling this.  My answer to the Nest thermostat, ugly isn't it.  Since I got an email yesterday that sparkfun is filling my order for sd card holders and I have 9 more boards to use up I am going to replace this with my "Power Monitor", a protoshield, and a serial lcd.  While the thermostat itself is not smart I will send the data to the database, and make it so that the computer can make the "smart" temperature choices and control the thermostat.  This is my second Nest rebuild, after first reading about their products before google bought them I built this...

The april board pulled power from the battery and was connected to the test button and the speaker.  It would read the battery level (which this setup would drain in about a half an hour), could remotely test the unit through a web interface, and would provide feedback to my xively feed.  The feedback was based on the number of pulses sent to the speaker and could report CO2, Fire, or Test.  This would have only been practical if the smoke/co2 alarm was connected to house power, but to my wife's frustration I had fun going to work and hitting the test button.  I had broken the link to xively one night playing around with the code and forgot about it the next day.  When I was showing it off to a coworker I was disappointed that my feed was not updating, but when my phone rang it proved to be a closed loop system just the same.