# Actuator\_outputs and actuator\_controls on Pixhawk

**URL:** <https://discuss.px4.io/t/actuator-outputs-and-actuator-controls-on-pixhawk/17452>\
**Category:** Uncategorized\
**Created:** [July 2, 2020, 2:17pm UTC](https://discuss.px4.io/t/actuator-outputs-and-actuator-controls-on-pixhawk/17452 "2020-07-02T14:17:08Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![francimala](https://discuss.px4.io/user_avatar/discuss.px4.io/francimala/32/6186_2.png) [@francimala](https://discuss.px4.io/u/francimala)\
**Post date:** [July 2, 2020, 2:17pm UTC](https://discuss.px4.io/t/actuator-outputs-and-actuator-controls-on-pixhawk/17452/1 "2020-07-02T14:17:08Z")

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Hi all, I’m trying to understand how to control a servo using AUX ports of Pixhawk, but I’m not figuring it out. If I’m not wrong, according to [https://dev.px4.io/master/en/concept/mixing.html#control-group-2-gimbal](https://dev.px4.io/master/en/concept/mixing.html#control-group-2-gimbal) publishing a value on control group 2 (for instance pitch) I should be able to drive the related AUX port, therefore I should see in “actuator\_outputs” topic, a value of that port different from 1500; am I wrong? I have tried different approaches, but the result is always the same: 1500 for all the 4 AUX ports.

I have also tried publishing on actuator\_controls\_3 (RC passthrough) which should rely on pass.aux.mix, but the result is always the same.

I have only the Pixhawk board, so I cannot arm the system, could this be the problem? What can I do to see a value different from 1500 on the AUX port (“listener actuator\_outputs”)?

I’m using all the default elements (airframe 6001). When I say I’m publishing on a specific topic I mean I wrote a module that is publishing on that topic some chosen values (publication on actuator\_controls\_2 or 3 is fine, I can see them correctly using “listener actuator\_controls\_2”, so it seems the mixing is not working).

Thank you for your attention.