[GeeTwo]

We're using a tape measure in our robot this year -- as a tape measure, of all things. We cut a hole in the side of the case and glued a volume knob to it, and fitted a 10-turn potentiometer into it. We're using it to measure lift height. Of course, since we can only go 10 turns, we can only use about 1/4 of the tape. It should be convenient to calibrate. -- Oh yes, it will probably also be in the field of view of the onboard camera, so the driver can read it as well if the resolution supports it.