Rev 1 I also added a USB Mini connector to make it easier to power ... lines available from the 40 pin package, 35 I/O lines to be exact. There could have been more except I like to make sure ...

Having a 32-bit processor with lots of memory running at 40 or 50 ... can just be breadboard wires if you don’t want to mount actual pins. The USB “connector” assumes that pin 2 is ground ...