# VOXL PWM AUX servo operate

Source: https://forum.modalai.com/topic/1748/voxl-pwm-aux-servo-operate
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2023-01-26 11:32:39 UTC by bensusana
Replies: 6 · Views: 1409

## bensusana · 2023-01-26 11:32:39 UTC

Re: [VOXL PWM AUX output not working](/topic/549/voxl-pwm-aux-output-not-working)

Hi guys
im recently going through the same problem as mention above.

just to be clear , i know that channel 5-6 (in pwm breakout board) are use used for gimbal , i want to know how can i use one of them to operate simple servo  .

i tried exactly the same as @Cole-Mathieu  tried in his post with no successes.

## Reply by Chad Sweet (ModalAI staff) · 2023-01-28 01:15:42 UTC

I don't think we have used a Flight Core PWM to control a servo at ModalAI 

Have you reviewed the PX4 docs? The Flight Core is a pretty standard PX4 flight controller, like a pixhawk

https://docs.px4.io/main/en/peripherals/pwm_escs_and_servo.html#pwm-servos-and-escs-motor-controllers

## Reply by wilkinsaf · 2023-02-06 18:26:27 UTC

I know that it works as we have gotten them to work with fixed wing servos. 

However, this was not an RC passthrough but something the flight controller was in control of. 
What is your PWM_AUX_MIN1 and PWM_AUX_MAX1 set to? Does the PWM min and max match the actually min and max of the servo on your gimbal?

## Reply by wilkinsaf · 2023-02-06 19:39:42 UTC

Putting together some outline into our setup to post on here

## Reply by wilkinsaf · 2023-02-06 23:53:46 UTC

@bensusana 

https://www.youtube.com/watch?v=fxfyrUW3EyA

I should have said "Aux 1 mapped to channel 5 FOR QUAD COPTER LAYOUT" instead of "for VOXL Flight" 

but other than that let me know if you have any questions

## Reply by bensusana · 2023-02-07 09:39:30 UTC (in reply to wilkinsaf)

@wilkinsaf first of all huge thanks for the effort of making this video :) ,
bottom line it worked ! 
only after i reset to default all the parameters like you showed in the video , now we have to figure what was wrong in our parameters that prevent this from working ( we tried the same thing with no success ! ).

now for next step we trying controls this servo through mavlink command without RC involved .

again thank you , much appreciate.

## Reply by wilkinsaf · 2023-02-07 23:46:27 UTC (in reply to bensusana)

@bensusana absolutely. Feel free to email me if you need a bit more dedicated support andrew.wilkins@ascendengineer.com. 

We have a bit of experience with ModalAIs products