Motor keeps spinning for some seconds after disarm


i have flown my Quad for some days now and mounted a servo gimbal. It required me to lower my refresh rates to 200Hz.
After that, Motor C didnt stop spinning after disarm, but it is really strange because the Quad still flies perfectly fine. It can even be observated in Mission Planners Motor Test function: If i test Motor C with 10% Throttle it spins normally, but then the throttle seems to go really low and it keeps on spinning for maybe 5 seconds. Then it stops. It is not a ESC calibration issue, I even calibrated them all with my RC Transmitter because i thought the calibration was the issue.

Maybe we can figure this out.
Thanks for your help


What rcio-dkms do you use?

apt-cache show rcio-dkms may help us figure out the version.

Your problem was fixed a while ago in 0.4. So if you’re using anything older than that I suggest sudo apt-get update && sudo apt-get upgrade. The Gimbal issue was fixed in 0.3. So I guess you definately need to upgrade!

Hi, it appears that my rcio-dkms was really outdated, it showed version 0.2. So I will upgrade it with your commands.
With Gimbal problem, do you mean that I can use the default 490Hz with the servos? That would be nice, but I think i read somewhere that the frequency of the RC rail cant be changed on some pins only?

So i upgraded to 0.6 and recalibrated the ESCs, but the motor still keeps spinning. I tested it again at 490Hz and at 490Hz RC_SPEED it works perfectly fine and all motors stop. But i can not use this high frequency, because my servos get hot when i do.

Maybe there is another solution i did not think of?

Yep! You can now set different frequencies for groups of Channels 1 through 8 and 9 through 14. This way you can set 490Hz for ESCs and 50Hz for gimbals. Take a look at this thread where the issue was discussed more thouroughly.

Alright, thank you!
Problem ist that I only own a NAVIO+ , so this won’t work for me, but im thinking about getting a second one so this is nice to know.
But the Problem with the Motor still persists…
Can u somehow Set different PWM for each Motor?

@Orli1 No, it is not possible to set different PWM frequencies on different channels on Navio+. That is a limitation of PCA9685 PWM generator and that is why we introduced STM32 microcontroller on Navio2. Workaround would be to use digital servos if possible because they can handle 490Hz without problems.

That’s why I set my RC_SPEED Parameter to 200HZ. My digital Servos can only handle that much. But the Problem that one Motor keeps spinning remains … Maybe it is connected to changing the RC_SPEED?