Hack a Day reader [Stephan Martin] has assembled a clever bargain-basement system using an Arduino-driven stepper motor and a reduction gear system built up from LEGO Technic parts, along with ...

This solar tracker system uses the Arduino UNO board, a servomotor, 2 LDRs and 2 resistors to rotate the solar panel towards the Sun or a source of light. Here https ...

Servos like this usually operate in radio control ... the servo motor stops moving. This pulse arrangement is very simple to drive from a logic output on an Arduino or other microcontrollers.