PCB fouls the USB/Ethernet jacks on the Pi

[amcewen]

I wasn't paying enough attention to the hardware on the Pi that the PCB mounts onto and so designed it such that it fouls the higher components - the Ethernet jack and USB sockets on a Pi 2/3, and also the composite video connector on the Pi 1.

We should redesign it so that it doesn't foul, although as a workaround we could use Pi Zeros, or stackable headers. (That's likely a reasonable first step, given we've got about 15 blank PCBs to use up first :-)