Maze - 90 Degree Turn Exact Calibration

[@ben.griffin]

Considering that battery, engine wear, friction, engine speed, dust on the wheels, and a whole bunch of other issues are involved in performing an exact right turn, would it not be better to use a self-calibration routine using the color sensor, gyroscope, and any other sensors that can be rigged to provide accuracy? With pylons, one might be able to construct a map which could then be used for dynamic calibration. My concern is that as soon as you take that bot off the test rig, it's going to go wrong.

[@LJCRIA]

When I did a series of these inside of a repeat-4-times loop (towards the goal of driving in a square), it would always skip one of the turns - both before and after upgrading to v3. Any ideas?