That's much simpler and smarter than what I was trying to do. I was also taking a much more general case where the algorithm allowed any intersection to be reached from any other.
I definitely want to make a more advanced, general-case version that can handle loops. It doesn't have encoders, which might make mapping difficult, but it can move at a very constant speed so I might be able to get by with raw timing. This was just my first stab at a maze solver that I didn't have time to start until the night before the competition, so instead of generalizing the algorithm I worked on (a) figuring out the non-looped solving algorithm and then (b) optimizing the performance.
But as far as what you did say, did you consider using port extenders for things like the reflective sensors to leave some general IO free?
Unfortunately we're not familiar with any devices that would meet our design requirements of bidirectionality with resolution of a few microseconds. The pulse lengths we'd be trying to measure from the reflectance sensors will typically range from 50 - 500 us, and we would like to be able to measure them with decent resolution. Do you happen to know of anything that would meet those criteria?
- Ben