Have you looked on our (ArduPilot) wiki ?
http://ardupilot.org/dev/docs/odroid-via-mavlink.html
Most of ArduPilot companion computer do control the vehicle using Python and Mavlink tool kit : Dronekit
http://ardupilot.org/dev/docs/droneapi-tutorial.html#droneapi-tutorial
Here is an example of an Ardupilot controlled by a Raspberry PI using Dronekit:
http://discuss.ardupilot.org/t/quadcopter-object-tracking-on-a-budget/18147/1