Throttle pwm value before inicialize

Hi everyone.

I’ve been 4 hours trying to solve this, and I’ve run out of ideas. I have an AUAV X2Q board, with arduplane 3.5 on it. Everything runs well apparently, but when I power up the system just from the main battery, my esc starts to beep and according to the manual of it, that kind of beep is due to an strange pwm input value.

I turns out that if I power just the flight controller, I wait for it to initialize, and then I power the esc, everything goes all right and works as expected. while connected to mission planer, just before it initializes, all the pwm out values are normal but pwm value 3, throttle, is outputing the maximum value, and I think this is the cause of my problem. I’ve been trying to play with ARMING_REQUIRE with no success, and calibrating the esc through different kind of ranges, no success neither. On the previous version of arduplane my setup was working flawlessly.

Anybody know how can I change the pwm value sent to throttle before it initializes?

Thanks in advance.



I see the same issue. If you need to get your plane started. After the system boots, plug in the USB cable to the Pilot so it has power from there. Pull the main battery and let the ESC re-initialise against pilot while it is booted. Then remove the USB.

It’s a horrible work around but it works.

The ESC I am using is HobbyWing rebranded. It comes in the HK kits as a no-name as well.

It’s not a solution but it will get you flying.


Thanks for the answer, that is what I did at first, conect a 5v battery to the pixhawk for initializing and then the main batt.

I realized if the esc doesn’t have pwm imput during boot, everything goes alright. I’ve installed a switch on the wire from esc signal to pixhawk. This way, the switch remains open while booting. Once pixhawk has boot succesfully, I close the switch and my esc initializes correctly. Maybe that can work for you also.