Android Thermostat is an open source thermostat project ideal for programmers and electronics hobbyists. As the name suggests the application runs on Android phone that is connected to some basic electronic components for controlling your home HVAC system.It costs around $140 to build and can be assembled in an afternoon.
It has several advantages over a traditional thermostat including the ability to easily create multiple schedules that are as simple or complex as you like, remote control access, monitoring of usage and easy updates over the internet. It’s API and open source nature means you can further customize the thermostat to perform additional functions.
The thermostat is fully functional but is in the very early stages. I would recommend it for anyone interested in tinkering with their thermostat at this point rather than the general public. There are many more features planned for future releases which you can view the details of in our subreddit.
Revision B Has Arrived - 4/5/2013
Introducing Version 0.4 - 11/24/2012
Version 0.3 Now Available - 10/26/2012