I finalized the design of my latest, greatest avionics ground bus (version 4). After some final development, I think this one will be successful enough to actually offer it to the homebuilding marketplace as a finished product. The new circuit boards and D-sub sockets have been ordered, and I have sourced a nice case to use.
Version 4 uses a 37-pin connector instead of a 25-pin one. This increased the size of the unit slightly. I also significantly improved the PC board design, and made some other major improvements.