The GPS controlled Power Wheels Gator was never quite accurate enough to actually mow our lawn, but the project was a blast none the less.
Slow Mow used an ArduPilot Mega and two brushed car ESCs to control the two rear motors. The front wheels were replaced with a single swiveling caster to allow the car to turn in place. To bypass the need for an external RC controller, an Arduino Uno was used to emulate its input.
Here’s a quick video showing it travel between GPS waypoints on the street.