Also done some electronic stuff. An expansion shield with one wire interface and an ID chip for each can bus node. Now I have to produce a few of them. The Id shield lets me use screw terminals for the Arduino connections and I have added 3 sockets for one wire with a 5V power supply for the one wire bus. One of the sockets is used to connect a id chip giving the component an unique id and the two others are connected to a socket for external use. It can be connected to a temp sensor junction box or a temp sensor can be connected directly.