Thruster Control Issue with Pixhawk

General Discussion
1

Hi everyone,

I’m working on a ROV project with Pixhawk, and I’m facing some issues. I’m using a Raspberry Pi as the companion computer, and I’m connecting to Pixhawk over MAVLink. I’m able to receive data from Pixhawk through a udpin connection. I’m successfully receiving the heartbeat signal and can send the ARM command.

I’m able to control the thrusters through QGroundControl, so I believe there’s no hardware issue.

I’ve set Pixhawk to GUIDED mode and disabled certain safety checks (e.g., ARMING_CHECK) temporarily for testing. Despite these changes, I’m still unable to send PWM signals to the thrusters.

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This is the code I wrote. I checked here (Pymavlink · GitBook)

Also this is my output

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The code works in the correct order, but I have a problem with the pwm signals reaching the thrusters, as far as I understand. If anyone has experience with this issue or can provide suggestions, I would appreciate your help.

Thank you in advance
Ömer

2

Hi @omer_1 -
Guided mode requires a position source to function, and I would not expect this mode to allow command of PWM signals- this should be possible in Manual or Stabilize / Depth hold modes.

A valid position source can come from a GPS, underwater GPS, USBL, or DVL system.

3

Hi @tony-white,

I will try to run this code on Stabilize mode then i will give you feedback about whether it works or not. Also can you check this code is correct? If problem still continues, do you know someone helps me?

Thanks.

4

@omer_1 @tony-white

For the individual control of motor thrust (PWM) you need set the ArduSub in the RCPassThru mode.

This parameter allows setting PWM directly for individual motors with values ranging from 1100 to 1900.

Check also BlueOS in-vehicle settings.

Regards,
Markus