dc motor as a variable resister? or potentiometer? or encoder

hey i was thinking about how you can turn a small moter and generate a small voltage can you use a arduino to mesure that voltage as a potentiometer of some sort? just curious

Not a normal motor. Perhaps a brushless motor, but I'm not sure.

Erdin: Not a normal motor. Perhaps a brushless motor, but I'm not sure.

Not really - although for a constantly turning shaft you can measure the number of electrical cycles and act as an encoder - but stationary motors produce no signal, and very slowly moving one's almost nothing.

What are you trying to detect/measure?