Arduino Keypad Door Automation. 45 Comments ... an allen key, a motor and belt from a broken printer, an old ... I guess he omitted the battery from the schematic and used a AC/DC power supply ...

[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 ...