This is implementation of controlling auxilary PWM outputs with a mission item (mavlink message id = 183).

[fpvaspassion]

Hello,
Some time ago I faced a problem with controlling servos attached to PX4 during mission execution.
After some discussion here
https://groups.google.com/forum/#!topic/px4users/_IrwFDOd2p8
I implemented this functionality.

Regards,
Michail.

[fpvaspassion]

I've tested it in flight, but unfortunately I don't have any logs right now. However I don't think they would be of any use in this case.

[89craven89]

can i merge this branch so i can give it a test?

[fpvaspassion]

Hello, yes you can do it.

[89craven89]

betwenn when you tested did you use the custom widget with the messase mav_cmd_do_set_servo?
because in qgroundcontrol the second parameter cant be used with more than 2 digits thus you cant set a normal pwm value to the servo

[fpvaspassion]

When testing i used it only in mission, here is the test mission to test servo on AUX6 output when flying betwen two points, first parameter is AUX chan id from 1 to 6, and second parameter is the PWM value.
QGC WPL 120

0 1 3 16 4 5 0 0 58.7106822000000008 35.828629699999999 4 1

1 0 3 183 6 900 0 0 0 0 4 1

2 0 3 16 4 5 0 0 58.7106336850431632 35.8289498448371887 4 1

3 0 3 183 6 2000 0 0 0 0 4 1

4 0 3 16 4 5 0 0 58.7106822000000008 35.828629699999999 4 1

5 0 3 183 6 900 0 0 0 0 4 1

6 0 3 16 4 5 0 0 58.7106336850431632 35.8289498448371887 4 1

7 0 3 183 6 2000 0 0 0 0 4 1

8 0 3 16 4 5 0 0 58.7106822000000008 35.828629699999999 4 1

9 0 3 183 6 900 0 0 02 0 4 1

10 0 3 16 4 5 0 0 58.7106336850431632 35.8289498448371887 4 1

11 0 3 183 6 2000 0 0 0 0 4 1

12 0 3 16 4 5 0 0 58.7106822000000008 35.828629699999999 4 1

13 0 3 183 6 900 0 0 0 0 4 1

14 0 3 16 4 5 0 0 58.7106336850431632 35.8289498448371887 4 1

15 0 3 183 6 2000 0 0 0 0 4 1

[89craven89]

Can you provide us with the qml file for this custom command widget?

[89craven89]

i still get the unsupported command message . I m trying to test it in manual mode , could this be the issue?

This is how i modified the qml file :

QGCButton {
text: "Servo Test"
onClicked: controller.sendCommand(183, 0, 3, 5, 900, 0, 0, 0, 0, 0)
}

[LorenzMeier]

I'm unsure about the testing state here - is this working or WIP?

[LorenzMeier]

This is crossing the abstraction layers and not something we should be generally doing. The right approach would be to publish to the actuator_control group #2 which is for payload, and to add a mixer in your airframe config which maps this to the output. The reason is that we want our architecture to scale to PWM but also UAVCAN.
https://pixhawk.org/dev/mixing#control_groups

[LorenzMeier]

You need to whitelist the mission item here now to indicate its supported:
https://github.com/PX4/Firmware/blob/master/src/modules/navigator/mission_feasibility_checker.cpp#L212