[ericand]

For the last few years, we have had at least one student designed PIC based processor on each robot. We still have not found a good way to communicate complex data back to the RC.

We use the external processors to do things faster (or in more quantity) than would be practical in the RC. For example, in Aim High, we had a pic that monitored our shooter wheel speeds. It could precisely calulate rpm once a revolution for both motors. The original plan was to feed back a speed value to the RC to let it adjust the power. As it turned out, that didn't work, so we limited the feedback to two digital I/Os for each motor that the PIC was monitoring. The digital I/Os were interpreted as:
00 - too slow
01 - just right
10 - too fast

The RC then ran a control loop to keep the speed in the just right/too fast area.

This sort of a project is not too dificult and provides an excelent opportunity for students to learn more about programming and the hardware software interaction at the microprocessor interface level.