I have seen a picture in the Wiki for the 2.0 APM board showing ouputs A9 to A4 being named "Motor LEDs".
Is there any explanation what that is and how is it used ?
For example can those outputs be used to power 12Volts LED strips ? (or is it max 5v out of these pins ?)
Maybe it would be good to add in the "optional additions" a little guide on how to use/add LED strips permanently lit for orientation of the Quadcopter against the sky background).
(I know there is a link in the wiki to have LED lit in function of the status of the APM via a special Jdrones IO board, but that's not what I'm looking. I just want to have permanently lit LEDs on the Quad arms for orientation, but I need 12Volts)
I am 100% certain you can not run 12v strip with the outputs of the atmega 2560 at a hardware level (fry the chip). 5v will be the output but even still the milliamp rating on the 2560 is not high. You should use a switching transistor to drive the leds and the APM motor led's APM outputs to the base of said transistor in conjunction with a current limiting resistor. a 1K would be where I started.
As for the actual details on the build I did not find much when I looked up the topic. Ultimately leading to your post. I believe you may have something to contribute if you sort it all out and document your build. Everyone could benefit a complete guide. Good luck.