Angle measurement for balancing robot.

[SteveB]

I don't know if it helps, but I seem to remember someone using "range finding" as a technique. They used two sonar modules to measure the distance from the top of the robot to the the floor, then did some less arduious math to compute the angle. I can't remember if this was a "concept" or it was actually implemented successfully.

Cool project, BTW. Good Luck,
SteveB