"proof of concept" using one raspberry pi to control two LEGO trains:
The trains are detected by reed switches. The Raspberry PI sends commands over bluetooth to the SBricks mounted on each train. The code on the raspberry PI is based on this code: https://github.com/J...ick-Stress-Test by GitHub user JorgePe. He also has details on the implementation in the SBrick wiki: https://social.sbric...client-scripts.
The only cable-connections are from the raspberry PI to the USB power supply (white box) and to the reed switches. Even at this early stage, this can be helpful on small train layout at exhibitions by adding some random elements in the timing.