4 ms·

I’ve been in the middle of making a similar system for my own apartment, mainly out of frustration that I keep forgetting to turn the heat down at night. It’s l

I’ve been in the middle of making a similar system for my own apartment, mainly out of frustration that I keep forgetting to turn the heat down at night. It’s less relevant since I’m working from home right now, but I also have plans to add geofencing to turn the heat down when I’m not there and back up again when I head home. I had the parts I need 3D printed, partly because it looks a bit nicer and partly because I need to replace the knob with one that’s easier to attach a servo to, and so needed something with a D-shaft. Designing those parts made me learn more about gear measurements than I ever thought there was to know. Like the author I went with the DS18B20 1-Wire temperature sensor, mostly because it was the first thing that came up on Sparkfun, so I’m glad to hear it was a good choice. I’m using an Arduino to drive the circuitry, sending the temperature and receiving control commands via serial over USB to my home server. This works pretty well (and allows for fancier logic than doing it all on the Arduino), but has the interesting result that when I’m compiling software the control program can get swapped out and my heat switches off (or rather, gets turned down to 55°F) until the thermostat daemon gets paged back in!

ysabri 6y ago
The last part about the thermostat daemon is pretty cool. I set the system to always switch off when it turns on. How fancy do you plan to go with the control logic?
- wolfgang42 6y ago
  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.

ysabri 6y ago

The last part about the thermostat daemon is pretty cool. I set the system to always switch off when it turns on. How fancy do you plan to go with the control logic?

wolfgang42 6y ago
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.