External LED - How to power


I have a pixhawk2.1 based copter.
I wanted to know if there is an easy way to add an additional LED (bright white light), to be used as torch?
Ideally, the light should be controllable from the GCS (mission planner).

I use a 4s battery, but I would prefer to power the external LED, from the pixhawk flight controller, if possible.


Have you tried this section of the documentation? http://ardupilot.org/plane/docs/common-relay.html