Rover has no PWM output


I’m trying to get a rover moving. Everything works nicely in Gazebo SITL, but now I’m trying to use a Pixhawk Mini with a rover. I’m uploading firmware directly using make px4fmu-v3_default upload. I then use QGC to load the Traxxas stampede vxl 2wd Airframe. Using MAVROS I can see the pwm output is typical for that of a Rover. My problem occurs on reboot. As soon as the usb cable to my QGC laptop is removed, the pwm output for all channels goes to zero. No matter if I power the Pixhawk Mini with a battery or if I hook it back into my QGC laptop, as of the first reboot, the pwm output is zero. If I switch the airframe to something other than a Rover, I see typical pwm outputs. If I switch it back to Rover, I see typical pwm outputs again, but only until the Pixhawk Mini is powered down for the first time.

pwm test -c 2 -p 1200 in the mavlink console works and I see the MAVROS topic /mavros/rc/out showing the correct pwm output.

System ID: 1
Airframe type: Rover
Vehicle: Traxxas stampede vxl 2wd
Firmware Version: 1.8.0dev
QGroundControl v3.4.4
Pixhawk Mini with companion computer running MAVROS

1 Like