Pwm system command is does not exist

Hi all,

For one of our Pixhawks, the pwm test command does not exist when trying to call it through the QGC Mavlink console. Opening the help page/list of commands (type just pwm) does not show test either, along with some other missing commands that I know from all the other Pixhawks I have been using.

I have already flashed the newest stable firmware (v1.12.3) but no change. Does it have to do with this ‘elderly’ looking Pixhawk 4 we’ve got? (All the others are out of stock these days…)

I appreciate any ideas! Thank you in advance!

TL;DR: If you need the pwm test command, use PX4 <= v.1.12.3.

It turns out I flashed v1.13.0 somehow which had just been released, where the pwm test/… commands have been deleted.

Trying to understand why one would ever want to delete these useful commands, I found there is a new actuator_test module in v.1.13.0. It seems, however, to have less capabilities as the previous pwm test command:

  • It is not possible to set a pwm_output device
  • It is not possible to set absolute pwm commands, only relative (-1 … 1).

It seems like this module is supposed to be used through this actuator page in QGroundControl. This is however only visible for dynamic control allocation, which is certainly not used for all vehicles.

@dagar What do I need to do to convince you we need the pwm test command back? It was the one tool we were using every time when setting up a new vehicle, to test servos and find save servo end positions (PWM values).