Nest 1st gen and 2nd gen thermostats no longer supported from Oct 25

This is one of the reasons I am working on an enclosure-compatible open-source version of the 2nd gen Nest thermostat. It reuses the enclosure, encoder ring, display, and mounts of the Nest but replaces the "thinking" part with an open-source PCB that can interact with Home Assistant. Nest has been pretty-badly supported in Home Assistant for over a year anyway, missing important connected features.

I've got the faceplate PCB done and working; the rotary encoder and ring working; and the display working but with terrible code with a low refresh rate.

I need to ship at the end of October to beat the retirement date. Plans to get some regular development report-outs and pre-orders are coming quite soon.

It's open source, and uses ESP32-C6 so it can be Wifi, BLE, or Zigbee, whatever software you intend to load onto it.

There is so much fun to be had with a rotary encoder and some sensors. What are your plans for extensibility? I think this would be an awesome hacker device — everyone needs a thermostat anyways, and an easy way to build new screens (volume control, door buzzer, whatever) and deploy to the device would be so cool.

I expect you’ll need to be heads down on the hardware and basic software problems to hit your dates. But I also think it’d be worthwhile to figure out the baseline for extensibility early. Maybe this is just a call-home mechanism so you can advertise updates, so you can do something more in the future.

I also wonder if you could somehow take advantage of ESPHome here, for very basic HA etc integrations (of other functions, to be clear).

Also, what are your thermostat algorithm plans? Are you intending to consume HA thermometers / sensors? Or perhaps expose programmability hooks directly on the device?