Hi - hoping for some help here. I did post this in the Pixhawk user group but no reply.

I am using my Pixhawk in a fairly complex fixed wing mapping drone and I need to free up some channels for some added functionality. Basically I am using Aux3/RC11 port for second elevator control and Aux4/RC12 for automatic camera shutter control (these are both using the appropriate RCn_FUNCTIONs).

Since these functions don't need their own RC input functions, I would like to move them to Aux5/RC13 and Aux6/RC14 ports so that I can use the freed up ports for other functions with RC input. Problem is I cannot get the RCn_FUNCTIONS to work on Aux5/RC13 and Aux6/RC14 ports. I have assigned the appropriate parameters for camera and second elevator, but they don't work.

According to the Wiki I should have 10 channels available for RCn_FUNCTIONs (ie. RC5 to RC14) so I'm pretty stumped!



You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • how I can  use channel 5 or 7 for change mode to RTL

    • Not sure I understand your question. 

      Why not just configure it using your Tx and flight modes selection in Mission Planner? Like you set up any other flight mode?

    • I have three modes in ch6 manual , stab , auto ,

      and i want to add RTL from the rc since I am not using telemetry to do that from mission planner during the flight ,

      hope you get the idea ?

    • I could help you if you have Futaba (there is a video I can dig out which is what I followed). Basically you use a combination of 2 position and 3 position switch and programmable mixing. What radio system do you use?

    • oh no my rc is JR

    • Have a look at this anyway, it's probably quite similar for JR:


      This way you can have 6 flight modes!

  • Developer

    Could you attach a dataflash log with you trying to use the outputs so we can have a look please?

    To confirm it was all working fine on RC11 and RC12 and you are simply trying to move them to RC13 and RC14?

    Make sure you don't have and of the RELAY_PIN# set to anything except -1.

    How are you powering the servo rail?

    Thanks, Grant.

    • Grant to the rescue again :-)

      Thanks so much, mate, all sorted. RELAY_PIN and RELAY_PIN2 were set to 54 and 55 respectively, so I changed both to -1 and now I have another 2 channels!!



    • Developer

      That's great news!

      Thanks, Grant.

  • Hi jacques, did you set the parameter BRD_PWM_CNT=6 to enable the six aux outputs to RC9 to RC14. It's set to 4 by default so Aux5 and 6 would still be digital.

This reply was deleted.