I start a lot of projects and never finish them. So in the spirit of documenting where I've been, here's my Poorman's Nest. Here I'm using
- one of my Microview's I had laying around
- A potentiometer (on pin A0)
- A small digital temperature sensor (on pin 3)
- A 4.7k pullup resistor
- A 220v relay (not shown, but follow the the yellow wire to pin 5)
Here's my code:
I abandoned this one because:
- We have baseboard heat, which draws close to 20 amps at 110V. I got a little nervous messing with this kind electricity.
- The relay draws about 200 mA when held closed. That's significant, and means the thermostat would need a fatty battery or a dedicated power source.
I might resume this project if:
- we move somewhere with a more modern 24V heating system
- I can find a latch-type relay that doesn't need power to keep it open or closed.