Potentiometer issues

[Alan Anderson]

A megohm is quite a large value. That's likely to result in a lot of noise on the Analog Input. A 10k to 100k pot is typical for a sensor in an FRC robot, with lower values giving better noise immunity but requiring more current.

If you're worried about "variable resistance", then you might not be understanding the proper use of a potentiometer. You're supposed to connect +5 and (-) across the device, and the wiper goes to the Analog Input. 5 volts is always across the pot. The output is a voltage which is proportional to the turning of the shaft.

The only way you'd need to be concerned with excess current is if you improperly connected the wiper to one of the power supply pins (or if you used a pot with much too small a value).