I recently moved the APM 2.5 board from a quad copter to my plane.
In the quad I was using a power module and everything woked just fine.
The equipment I have:
Airtronics rd6000 super TX
Airtronics 92777 FM reciever
APM 2.5 borad (with the latest firmware)
Currently no GPS (till I'll figure out whats wrong with the setup)
On the plane I am not using a power module, the ESC is connected to the 3rd output on the board but when I connect the battery to the ESC, nothing happens, the motor beeps because it senses the power from the ESC, but the APM board doesnt fire up. When I am connecton it to the USB everything works fine and I can calibrate the radio but when I only plug the battery via the ESC nothing works.
What am I doing wrong?
What ESC are you using? If the output power is 5.5V you probably ok (JP1 in place), otherwise get another PM or uBEC that output 5.5V and connect it to the outputs rail. Only connect a BEC to the inputs if it's 5.0 +-0.25V.
the output rail power does not provide power to the cpu unless you attach the JP1 jumper. That's not a good idea though because then the power for the servos would be shared with the power for the CPU so as the servo moves it'll cause ripples on the CPU's voltage and you can get brownouts and other bad behaviour.
Best to use the power module, that is the easiest and safest way to power the board. Failing that a 5V BEC feeding power into the input rails will also work.