For the first version I’m just doing a hard-coded daily schedule, plus a button to bump the setpoint up briefly if I get a chill. The server is still useful even for this simple setup because I can just use the NTP-synced system clock instead of having to mess around with an RTC on the Arduino, and also so I can log things for later analysis.

In the long run, I have a bunch of ideas bouncing around in the back of my head that I might get around to eventually: the aforementioned geofencing, interfacing with an automatic alarm clock (also not built yet) to turn the heat on right before I get up, detecting when I go to bed rather than having a set schedule, determining my preferred temperature based on the weather (I think I mind the cold less when it’s raining), running the ceiling fan (in the summer, and maybe also to pull heat down from the loft in the winter), and so on. No idea if I’ll actually do any of them, but the option is there.