It's ALWAYS the wiring
There's a long standing idiom that if you can't find the problem, it must be the wiring. And since I was having trouble diagnosing stuff, I assumed I had to have made an error designing the PCB. So I hacked in some diagnostic bits, you can see in the previous post. I'll be incorporating those into the next version of the pcb.
EXCEPT when it's not the wiring, but you forgot a line in your code, and caused it to get stuck in an infinite loop. Oops.
