Nearly all auxiliary heaters on the market use a serial communciation between the control panel and the heater. Our goal was to integrate these communication protocols. There are some major differences between each system. The protocols and the used communication hardware had to be reverse engineered for each heater.
normal uart 5v ttl with a baudrate of 19200 8N1. Be careful: on the red wire are 12v output for the control panel so only connect tx,rx & gnd.
Websto - W-bus devices
k bus baudrate 2400 8E1 - OBD K-bus cable
Chinese Diesel Heater
ttl 5v halfduplex - one wire We are using an Arduino Nano Tutorial here!!
done via 433MHz, tutorial to be published...
not fully done yet,
Implementation in Node-Red
Each heater has its own flow. In the respective flow is the actual communciation setup. On top of these flows there is a 'heaterController' flow. This flow interacts with the heater timer and the touchscreen.