So long as the 0V rail is connected to the Arduino 0V rail, the positive rail can be any dc voltage – more or less that the Arduino, so great for 12V motors. And it is compatible with both 5V and 3V ...

This design uses a geared DC motor, ... Pin headers at the edge of the PCB connect to a second PCB ... The motors are driven with a stack of motor driver shields on top of an Arduino ...

Running a brushed motor in muddy or dusty environments takes a toll on controllers, with both heavy back EMF and high stall currents. This explains one of the challenge in Europe’s Hacky Race… ...