An Arduino is used to determine the servo’s current position versus the desired position, and it turns the motor accordingly with a BTS7960 motor driver.

A starter kit for the Arduino Uno open-source prototyping board which can be used by professional embedded system engineers and students is available from RS Components.

[Frank Herrmann] had an interesting idea to turn a geared DC motor into a servo motor assembly, but with a stepper motor-like interface. By stacking some small PCBs behind the motor body, it was po… ...