Motor shaking issue


#1

https://drive.google.com/file/d/1ENVJIr17W-FmL7K-jPN_Iv06Ump9Hc5r/view?usp=sharing
I have a motor shaking issue when using the Magni, it does not happen every time but quite often.
the procedure is:

  1. turn on both power, black switch and red switch
  2. the magni can be controlled by a joystick
  3. turn off red switch only (the motor power)
  4. turn on red switch
  5. try to control the magni by a joystick, and it does not work, the motor seems like not powered, I can spin the motor by hand, but it seems like it’s trying to get powered because it is shaking. I shared the video to you.

#2

This sounds very much like a known bug. We have the ability on rev 5.0 boards using hardware changes to detect the situation of the motor power being off and we zero the PID control loop till motor power is restored.
I have written firmware which is not released yet but it will require hardware changes only on rev 5.0 boards (current production run) and will also require a new firmware release. Normally the issue is the Magni starts to drive a little bit and should not. But this defect does sound related.

It does require a hardware change so is not possible to fix on boards prior to rev 5.0 and we are aware of this situation leading to assorted issues.