Underfloor heating is in, because it spreads a pleasant warmth and manages with energy-saving, low heating water temperatures. In most cases, the water flow to the floor heating coils in the individual rooms is centrally controlled via electrically operated valves that are located in a distribution box embedded in the wall.
If you have made your home smart with a Home Assistant Server, these are basically ideal prerequisites for integrating the heating control. However, there is one hurdle to overcome: the valves are mostly operated with mains power, i.e. 230V, and only rarely have a network connection. Therefore, an additional, usually quite expensive controller for several hundred euros is necessary.
on Github now has the designer Voltlog presented a corresponding controller that can control up to ten underfloor heating valves. The device that goes for about $ 100 as both Buy finished device is, but through the board layout files published on Github (in KiCADFormat) can also be built by yourself, works with an ESP32. Using the Tasmota and MQTT firmware, it can receive commands via WLAN or deliver data to Home Assistant or other smart home servers.
There is also a 1-wire port on the board, to which temperature sensors, for example, can be connected. The valve controller is supplied with 230V. Batteries are therefore not necessary. The outputs for the valves are switched using triacs.
Programming is only done the first time by cable. After that, the firmware is OTA-capable: Updates are therefore wireless (Owatch the air) transferred via WLAN.