Today we completed the Pi-Cade.
We were interrupted briefly a small group of Bangor Academy students (who were not in the project group) coming in and marvelling that this sort of thing was being made at their school, in their Technology class.
The problem we had was with the pins-GPIO mapping. The instructions we were using, sourced off the Internet, were incorrect. Through a lot of trial and error and swapping pins about, we managed to figure out where the errors in the mappings were and modify the breadboard accordingly.
The teacher, Mr Pollock, is now taking the new pin layouts and intends to make some PCBs which will make the layouts permanent. As we have another set of joysticks and buttons, the intention is now to make a pretty one.