Hi all,

I cannot arm ESCs in stabilize, acro and simple modes.  Each turning on the green led stays off for about 5-10 secs, than green-red are blinking, and than green blinks (is this "one-time ESC test"?). Moving rudder left or right for 2-10 seconds does nothing, green still blinks.

There's ~400Hz PWM signal (not 200) from  outputs 1,2,3,4,7 and 8 - all are motor outputs, I think. Outputs 5 and 6, however, stay normal and happily drive camera stabilizer servos.

I've downloaded the latest Mission Planner, burned APM with Arducopter 2.0.50 (quad X). There was no major issues in setup process. Except "Missing RC Rev param" alert, but the program correctly displayed the movement of Tx's sticks. Also, no reverse checkboxes saved. But I was able to adjust all necessary params  in the transmitter. However, both modes selector and leveler were allright. Manual calibration passed as it was expected.


Automatic calibration: green led is not blinking, motors beep 123 instead of usual 123-1.-1..-1...  and no calibration happen.


My setup: "Arducopter kit, completely assembled and tested" with no additional sensors, Pentium-30A ESCs, Spektrum DX8+AR8000, running at conventional 22ms interval.     Pentium-30A, connected directly to AR8000's throttle output, behaves as expected.


Connected to any  of motor outputs with that abnormal PWM, it starts to slowly rotate motor, as at 1100-1200 CV. An analog servo, connected to the same output, have burned out in 5 minutes with very bad smell. And there's motor log:


DATA: 10, 4600
DATA: 11, 4600
DATA: 12, 145
DATA: 13, 145
MOT, 1100, 1100, 1100, 1100
MOT, 1100, 1100, 1100, 1100
---same  strings, no matter what I've done

MOT, 1100, 1100, 1100, 1100
MOT, -1, -1, -1, -1

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It worries me you've reverse some channels.

Enter CLI mode and go to:




Right roll and pull back on the stick should output about 4450.

Right Yaw should output about 4450

Note the position of CH7 switch. the default position should give you a low value.


Nothing was reversed, although I've extended yaw.

Okay, changhing  values according to your recommendations..

Roll right: 4455

Yaw right: 4470

Ch7: 0


Flight mode.


Tones 123 - 111 - 1long (ESCs maybe think they have normal low-throttle signal)

red and green flashes after 10 secs

green flashes

Setting yaw right for 3 secs.

Green still flashes.

Same high frequency PWM.


Nothing has changed.

Maybe I should buy another Ardupilot Mega?

I realized that thisi is a common problem and still nowhere a solution given:


two by jerlac2

three and more from 1st coment. Arming doesn't happen.




not followed the links in your post above to see, but i have the same radio set-up and initially had a similar issue.
i fixed it by going into servo set-up on the DX8, select the throttle, and increase the travel param to 110% at each end of the range.
hope that helps

Thanks David, your advice have moved me from the dead point! ESC's beep like they have too much throttle at the lower end so I think now I can drive the system to its best.

you will need to reset your esc's once you've done this - you probably know this - remove esc's from apm, and set up so you have esc connected top receiver and a motor, but no power to esc, switch radio on, full throttle, power to esc, hear beeps, throttle to min, hear beeps, done.

and obviously you need to do this for each esc.

Thank you, but I shouldn't do this. Apparently my problem was in calibration:

At first manual calibration I've set lower throttle to 100% and got 1100 CV.

Next time I've set it to +-110% but still had no result because APM CV were slightly higher than Rx CV.

So I calibrate ESCs  at Throttle[-99;110] and then set it to [-110;110] to have a "room" for initial control signal. Only that makes motors rotate, although APM start takes about 20-25 seconds now...

Yes, as i expected before, my only working settings are:

ESCs calibrated with [-98%;100%] throttle

And working throttle is [-105%;100%]

This probably happen because throttle calibration is not saving and "Missing RC REV param" appears on every MP calibration.


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