Mark IV

So, after getting Mark II to its current state, I decided it would be nice to actually have a bunch of ready boards like that, with a switch and maybe a capacitor. I sat down and designed the newest version:

Depending on which holes you populate with male/female headers, it should be able to accept a variety of boards -- all the boards supported by Mark II, and also an ESP8266-1, PyBoard, ESP8266-12 on a breakout, etc. It won't work with Raspberry Pi or Arduino UNO -- that's impossible for this size.