I believe you want the esp8266 or esp32 microcontrollers with esphomelib: https://www.home-assistant.io/blog/2018/06/05/esphomelib/ https://www.home-assistant.

I believe you want the esp8266 or esp32 microcontrollers with esphomelib: https://www.home-assistant.io/blog/2018/06/05/esphomelib/ https://www.home-assistant.io/blog/2018/06/05/esphomelib/ You can get esp8266 devices as cheap as about $1.30 on Ali express or you can get the super tricked out ones (mainly just for prototyping) from adafruit for about $9.99. They call theirs the Huzzah and it comes with stuff that you don’t have to solder on to most esps anyways. But a small cheap wireless sensor (3.3V) that can attach to any small sensor makes for some interesting automations.