It turns out that the first iteration of the hardware meets the criteria for the Return Of the Square Inch contest!

This may be cheating just a touch. It depends on your point of view. What I refer to is the need to connect the board up to some sort of dumb terminal to actually get it to work. But when has that ever stopped anyone?

I'm going to add the requisite files for the first version to the files section of the project. There's still plenty of time before the contest closes to make sure it actually works.

Of course, since we're leaning on the idea that the base badge would supply us with a dumb terminal, then it's pretty darned simple to use an ordinary FTDI style USB UART adapter / cable to do the development (provided you get one that's 3.3v). My own FTDI-be-gone will do nicely.