This low cost project is a RC servo like position control of one or two geared motor(s) with a pot as angle feedback. You can send the arduino microcontroller a value from 0 to 1023 and the arduino will control the motor speed and direction to reach your target value. The PID algorithm will insure that the motor will not get into hold vibrations if the pot has some influences. This article will describe where you have to take attentions and what you have to setup to get the best results...