# PWM channel control for auxiliary functions Source: https://forum.modalai.com/topic/2172/pwm-channel-control-for-auxiliary-functions Category: VOXL 2 and VOXL 2 Mini (https://forum.modalai.com/category/26/voxl-2-and-voxl-2-mini) Tags: voxl-2-io Posted: 2023-05-18 23:29:09 UTC by Filip Slezak Replies: 3 路 Views: 1758 ## Filip Slezak 路 2023-05-18 23:29:09 UTC Hi all, How should I go about controlling the PWM channel 7 or 8 (hexacopter airframe) from VOXL2 code and/or remote control? I can't find where the AUX channels are mapped Thx ## Reply by wilkinsaf 路 2023-05-19 04:05:53 UTC This was completed with the VOXL Flight Core: https://www.youtube.com/watch?v=fxfyrUW3EyA Not sure if it helps on the VOXL2 IO ## Reply by Filip Slezak 路 2023-05-20 02:52:21 UTC Yes, thanks. Although incomplete 馃檪 Need to configure `quad_x_io.main.mix` (`find / -name "filename"`) with the code below where X is the channel defined in the 2nd link below (AUX1 5 or AUX2 6) ``` # Hexacopter X airframe config R: 6x ... # For each AUX channel M: 1 S: 3 X ... ``` Writing this from home, sorry for '...' but simply copy the config to quad_x.main.mix to quad_x_io.main.mix, both these files are loaded on boot and if the io board is connected it overrides the former AUX1 will be on pin7 and AUX2 on pin8. 1) https://docs.px4.io/v1.12/en/concept/mixing.html 2) https://docs.modalai.com/voxl2-io-user-guide/#supported-mixers-and-airframe-setup Or properly rename the file and change the name being loaded in the px4 startup script but I didn't do that to avoid issues in case it's used by something else too... ## Reply by Filip Slezak 路 2023-05-20 02:59:18 UTC Any tips on how to control this from ROS for offboard mode?