I have built a similar system, and expanding it to more devices (think: devices other than thermostats). However, I use my own custom messaging/web server for

I have built a similar system, and expanding it to more devices (think: devices other than thermostats). However, I use my own custom messaging/web server for communicating with the device from anywhere in the world. Think controlling your (ex: toaster) in NYC from LA without configuring any networks, vpn, ports,...aka Nest-like. Combined with some machine learning and machine "thinking", its pretty powerful. The Spark Thermostat is great minus the fact that you need their web api for communicating with it. But for a 1-day build, how can anyone disappointed! Great job Spark team. In regards to my own devices, I am definitely going to have to take a look at Spark now. Cool hardware.