I am working with a DC motor from Bosch with a potentiometer, Unfortunately, the datasheet is not clear enough on how I can operate it, and how the potentiometer will influence it.

VMC Pins:
1 - GND
2 - (?)
3 - 2V5
4 - GPIO
6 - GPIO

The orientation of the rotation is clear:

Clockwise       4 UP (+), 6 UP (-)
Anti-clockwise  6 UP (+), 4 UP (-)

What exactly is the role of the potentiometer for torque control? Should I connect pin 2 to a timer for PWM control?

Datasheet link


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2 Answers 2


The potentiometer is not used for torque control. It's used to sense the position of the output shaft, so you can servo-control its position. Note that there's a 405:1 reduction from the motor to the output.

If you actually want to use this motor for continuous rotation, you will probably be lucky and find that the potentiometer does not have rotation stops, and is able to rotate freely. There's no point in the manufacturer making something that physically breaks the first time a user energises the motor without a position control loop working. In that case, you can use the output of the potentiometer to indicate the angle the output shaft, or to count the rotations.

If you want to control the torque of the motor, feed it from a constant current source.


The potentiometer is used to get feedback on the output shaft. For example, you can use it with a PID controller to set the angle of the output shaft.


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