Pixhawk 6c no servo movement/output

ArduPlane
1

I’m setting up a new pixhawk 6c on an airplane and after doing all the basic setup, loaded firmware, calibrated radios, etc. I’m not getting any movement from the servos which are connected to the FMU PWM Out plug on the 6c. The main motor with the prop is connected to Ch 3 on the I/O PWM Out plug and spins to full power when armed.

FMU PWM Out Ch 1 is aileron, Ch 2 is elevator, ch 3 is rudder (these are servo outputs 1,2, & 4) in APM. +5v in connected to ch 8 on the FMU PWM plug output rail for power, measuring 5v at all of the power pins.

Safety switch has been disabled with BRD_SAFETY_DEFLT = 0 (agin the prop spins so I can rule this out). Attaching a log file for reference.

I have seen some similar posts, but no resolutions in any of them. Any help troubleshooting would be great.

2024-04-14 17-29-03.tlog (174.7 KB)

2

The servos should also be on I/O PWM Out.

Or if you want to use the FMU then they would be setup as servos 9,10, 12.

3

Thanks for the suggestion. I tried it both ways and same result - no servo movements.

4

If you’re testing the servos without arming you’ll need to set BRD_SAFETY_MASK for the outputs you have the servos connected to. Just note, this won’t do anything for the throttle. Throttle only works when armed.

5

I tried a fresh install of arduplane firmware and servos worked on 1, 2, and 4 of the I/O PWM out, as you mentioned above. I did also disable BRD_SAFETY_DFLT. Thanks for the help!

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