Based on the earlier design, I created a new, smaller PCB. This version is more for switching lights and
signals, but can be used for relays and track switches as well. The firmware is still the same. So check the original manual for all firmware options.
This version contains even less components, is smaller (a PCB of 10cmx10cm contains 4 decoders) and contains soldering jumpers for (future) firmware options. Extra jumpers are present, so that we can use a common ground and switch to V+ (instead of using a common V+ and switching to ground). In that case, an alternative for the ULN2803, like the TD62783 should be used.