Navio2 PWM output issue

Dear Community

We face a problem related to the motor control on our drone.:

Hardware setup:
We use a RPI-Navio2 unit that drives a PWM signal to a CastleCreations Phonex Edge HV 60 Motor Controller.
The GND and SIG wire lenght between Navio2 and Motor Controller is approx. 2 meters.

Problem:
Our motor driver was not correctly receiving its control signal at high motor rpm’s OR high motor dynamics.
I attached a screenshot of the Navio2 Servo output channel and a screenshot of the motor drivers signal input.
Observe the corrupt signal reception in the castle data log between 340 and 345 s, which causes our motor to loose power and therefore bad drone controllability.

We have previously seen that a small standard servo motor was not following the RC controller stick position, when it changed its setpoint very fast (eg. rudder full right and then let stick jump to middle positiion). Then the servo was just holding its old position at full flapp deflection instead of returning home again.

Therefore we suspect that something is not working correctly with the Navio2 pwm generator. (We use 100 Hz PWM base periode).
Somebody seen some similar behaviour on their drone?

What is the maximal signal cable length that the Navio2 should be able to pass its PWM signal through?

Best,
Damian

Hi Damian,
I would change the frequency to 40 or 50 Hz, since that is the frequency the servos are intended to work with; not sure about the ESC.

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