X8R SBUS and servos

[sirch]

I've done a lot of Googling but I can't find much information on this. I am using an XRC receiver with the sbus connection to a Pixhawk PX4. I also want to connect a servo to control a camera gimbal and I am wondering if it is as simple as connecting the servo to one of the outputs on the X8R or does that fact that I am using sbus mean that the other channels are deactiavted?

[Coyotte]

Hello Sirch,

As per X8R documentation, you could use Mode 4 which set channels 9 to 16 on the receiver outputs.
This should allows you to use controller needed channels via SBUS as also channels 9 to 16 to control servos directly from the receiver.

Coyotte

[sirch]

Thanks Coyotte, I guess I could rebind it in mode 4, not sure how I do that but I'm sure I can find out. The other thing I realised is that the PX4 has servo outputs so I might try those instead.

[Coyotte]

Hello again,

According to manual, to bind in mode 4, you have to connect signals of channels 1 and 2 together as also signals of channel 3 ans 4 during the binding process ((using the little jumpers furnished with the receiver).

By the way, receiver manuals can be found on Frsky site if you lost them.

Best regards,

Coyotte

[sirch]

Thanks again, I found that info but my TX/RX are already bound and I don't know what mode so I will have to un-bind and then bind them again. Anyway I think I'll try the servos via the PX4 first and see how that goes

[sirch]

Just feeding back on this because there is so little information about it. I have got the pass through AUX working on the Holybro PX4 Pixhawk board. Some of the steps below are obvious but I thought I'd be as complete as possible.

• The Flight Controller FMU-PWM-OUT needs to be connected to FMU-PWM-IN on the power board
• It is necessary to power the FMU-PWM-Out pins separately with a BEC.
• Pin 1 on the FMU-PWM-Out header seems to be AUX-1 in the firmware (there is literally no information on this anywhere on the billions of pages indexed by google).
• It is necessary to assign the radio channel in QGroundControl
• The servo only works when the drone is armed

[tipsy trucker]

I did this just the other day so to answer your original question;

Put the little jumpers between the signal (top) pins on channels 1-2 and 3-4. It'll look like those 4 channels are all missing the top pin if that helps you to picture it.

Next, turn the taranis on and tell it to bind (short press menu, find the screen with lots of options, iirc it's the second or third screen, and scroll down to "receiver" - make sure you're on "D16" and where it says ch1-8  you need to change that to ch1-16). Click [bind] and it acknowledges somehow.

Now, while holding the bind button down on the receiver, turn it on or plug your battery in and watch the led. It'll change to a steady green light almost instantly and hey Presto you're done!

You now have channels 1-8 on the sbus and 9-16 (1=9 & 8=16) on the normal outputs (after you've removed the jumpers that you used earlier) telemetry and smartport will work too.