Issue on 3.4rc1, 3DR Pixhawk, FrSKY X8R sBus

Hi all,

I’ve an issue with my setup:

*3DR Pixhawk
*copter 3.4rc1 Craft and Theory version
*X9D+ TX
*X8R RX Mode 4 Config
*SBUS wire connected to RC IN on Pixhawk

I cannot control the landing gear which is connected on channel 8 of the Pixhawk.

Setup seems ok, the landing gear option is selected on APM Planner (Mac) in advanced setup configuration/channel 8 options

Radio is well configured, if I use the channel 9 on the Taranis (therefore using a direct wire from the X8R channel 9 output) I can control the landing gear, when I setup the control back to channel 8 (which goes through SBUS to the Pixhawk) I cannot retract the landings.

The same happens with the lights, which used to work but when I moved their control on channel 12 ( Pixhawk RC12, Aux4) they are fixed on.

Motors, flight modes which go on SBUS too, work properly.

What Am I missing?


First, we are in rc2 so that is what you should be testing now.

Second, if you decided to use a firmware produced by someone else, why are you in the official ArduPilot forums asking for help instead of asking to the people that produced that firmware?

I have to agree with OXINARF that it would be great if Craft & Theory would help with the support of testing of software they produce. Saying that, we do very much welcome companies and individuals using the code, forking/modifying the code and building businesses around the ArduPilot code base of course. It’s just about sharing the support burden is all.

In any case, I’m sure you’ve seen the Landing Gear wiki page?

Also, with -rc1 it’s possible that the auxiliary pwm output channels don’t move until the safety switch is pressed. Now, if you’re using a NAVIO2, it doesn’t have a safety switch anyway, I think. Still, this change we made comes to mind. I think it’s resolved with -rc2 though… i.e. the auxiliary outputs do move even before the safety switch is pressed in -rc2.

I use the C&T interface/firmware (Currently 3.4-rc1. I know rc2 is out…) and I had this exact issue when I switched from using PWM straight from an X8R receiver to using an AUX output from Pixhawk.

What threw me was the values for LGR_SERVO_DEPLOY AND LGR_SERVO_RETRACT were backwards.

I must have looked at them half a dozen times before the lights came on.

@rmackay9 Thanks for your support and I apologise for the delay of my answer.

I followed all the instructions on Ardupilot wiki, likely the issue could be related to the PWM outputs. I’m going to test it today.

Thanks again.

I’m going to check this as well. Thanks.