I was looking for a position (strobe) light for my F450-based quadrocopter when I came across this ready-to-use LED module with JR connector attached.
(Image source: amazon.de)
As there was absolutely no documentation at all, I had to do some reverse engineering to find out how to operate that thing. Using an Arduino I managed to activate it with a PWM signal of 1kHz frequency at 70% duty cycle.
On the FrSky X8R receiver you can just plug it in one of the conventional outputs (remember: ground down) and assign a suitable channel on your remote, that's it.
Another good thing about that LED module is that it stores the selected blinking mode in non-volatile memory, so you don't have to set it up each time again.