I'm having a problem getting the APM2 to work with the DJI ESCs and motors I just got.
I have the DJI 30amp 11.1V ESCs with the DJI 920KV motors. I have everything plugged in into the APM2 and when I plug the battery in all the ESCs/Motors give the abnormal input signal beeps and none of the LEDs turn on on the APM2. When I plug the APM2 into the computer via the USB (before I connect to the Mission Planner) and than plug in the battery I get the ready beeps. When I disconnect the USB (with the battery still plugged in) I get the abnormal input signal beeps again.
I know that the APM2 I have can work because I built a GAI 500x with the APM2 on it and it flew wonderfully.
UPDATE: I ran through the configuration in the Mission Planner and after I did that I was able to run the motors command in the CLI and it worked! I was even able to arm and throttle up the quad when it was plugged into both the computer and the battery. But I still get the abnormal input signal beeps and no APM2 lights with only the battery plugged in.
Additional DJI ESC information.
Apparently at an early rev they had built in BEC's but now apparently do not.
They are optically isolated and quite possibly the internal BEC defeated the isolation.
They have a reputation for being extremely reliable and on the Flamewheel 450 and 550 series max power for the motors is less than 20 amps so at 30 amps there is plenty of surplus but you will need to use an external BEC.
A 5 amp switcher from HobbyKing is available for under $10.00 and has 90% plus efficiency (way better than linear regulators).
Finally the DJI BEC's are apparently Not Programmable, but are balanced from the factory and do not require nor support (balancing) as in the APM set up procedure.
You may, however, need to adjust the throttle trim to allow below zero throttle in order to achieve APM lock.
I have now purchased a FlameWheel 450 and will report any findings on a separate Blog devoted specifically to using the Flamewheel with an APM.
I will also up date the set up section of the Arducopter Wiki to cover use with the Flamewheel and it's ESC's once I have brought up my system.