OpenThermShield #

OpenTherm adapter/shield for the wemos d1 mini

The primary goal was low cost, speed and manufacturability. The components were gather in the Edinburgh Hacklab and milled on the PCB mill in 1 day

My boiler is a Vokera Unica 35C

Photos #

Schematic #

The pinout works if you flash the OTGateway firmware and swap the in/out pins in settings (like in the esphome.yaml), but imo esphome works better so if you're running HA highly recommend that approach

PCB #

Case #

Check out OpenThermShield - Case.3mf (support for bambu-studio). The case was also designed quickly so beware of the cover mount holes being too small. The USB power supply used

esphome.yaml #

ESPHome config for the controller