A maze solving sensor array for line-based mazes. The array would need to have a downward-facing IR sensor arrangement of:
E E E E
R R R R
E = Emitter
R = Receiver
so that the two outside sensors could detect intersections.
This should be relatively inexpensive to manufacture and modify mBlock to use (expansion on the current line follower sensor code). Ideally it would work with the mBot, Starter Robot, and Orion boards.