PI Like Control with Pots

[Tom Bottiglieri]

I have run into a problem. Our main arm is powered by 2 fisher price motors, and is subject to backdrive when the arm is extended too much. I have a pot connected to it to drive to pre set positions, and I was wondering if anyone has had experience with coding a control loop that is driven by a potentiometer. Normally, I would research this topic, but with one night left to get this working, I need help.

Right now i am using a basic "check and correct" function. I have the code so when the joystick is neutral, it grabs the pots value. Then in the following program loops if that value deviates from the original, it will drive the motor accordingly. This is not working very well. Our only other alternative is a mechanical brake, but we do not have enough time to do this.

Please help me with this...

Thanks,
Tom