RC Passthrough to PWM out on PX4 FC via AUX 1 / 2 in QGC

1

Hey @Michael_Oborne,

We have a PX4 flight controller connected to a HereLink v1.1 via UART and it is communicating with the Ground Station well in QGC.

Our goal is to map the AUX 1 / 2 buttons to a PWM channel on the flight core in order to control actuators from the flight controller.

Is there a way to do this natively or any recommendations on a path forward?

Thank you,
Aaron

3

im not sure what you mean by AUX 1 / 2

but if you want buttons to control a pwm channel, you can user the herelink settings app.

4

Hey @Michael_Oborne,

Our goal is to map 2 SBUS channels to 2 PWM outputs on a flight controller.

Specifically, we are trying to map the scroll wheel to SBUS1 CH 10 and buttons “C” and “D” to SBUS1 CH6, then have those SBUS channels drive a corresponding PWM output. For this specific use case we have a CUBE+ Orange and would like the PWM from the scroll wheel to drive the PWM output on the CUBE via “AUX OUT” Ch 1 & 2 respectively.

Currently in QGC, in vehicle settings on the radio tab, we have channels 10 and 6 responding to the button signals appropriately.

What we cannot figure out is how to route SBUS1 Ch 6 & 10 to output PWM on a CUBE via AUX OUT ch. 1 and 2.

I don’t understand where to correlate the SBUS channel assigned to a button, to a specific PWM output on a flight controller

Would you be able to help me understand how the mapping works with the herelink settings app to do what I explained above?

Thank you for your help with this.

Best,
Aaron

5

Hello,

What we cannot figure out is how to route SBUS1 Ch 6 & 10 to output PWM on a CUBE via AUX OUT ch. 1 and 2.

You cannot do this becos none of the Aux channels are input channels. They are all output channels.

6

Hey @sibujacob I understand that the AUX are only outputs.

We are trying to map an RC in from the SBUS channels on HereLink to drive AUX outputs on a flight controller.

SBUS channels are mapped to buttons and show up in QGC proper.

I am having difficulties mapping these Sbus channels of RC input to an output on AUX 1-6 channel of the flight controller.

So goal is to: map buttons and scroll wheel on Herelink to PWM outputs on a flight controller. Perhaps this is done is some type of parameter mapping?

Any insight would be helpful, thank you

7

Hi,

You can set it up using the following video

8

Thank you @sibujacob I will go through this

9

Alright, after some investigation we have decided to go with direct SBUS control from the airunit, rather than routing the SBUS signal through the flight controller to a PWM out on the AUX (1-6) rail on the cube.

Our current control method now is using SBUS2 directly to the peripheral for control via the SBUS2 channels directly without any routing or mapping of signals on the CUBE.

The issue was that on SBUS2, Channel 17 is recognized as RC Channel 1. So after setting up the scroll wheel to Channel 26 on SBUS2, the RC control communicated properly when set to Channel 10. Essentially, on SBUS2 you need to take the SBUS channel number and subtract 16 to set the RC channel appropriately.

Thank you for your help on this @Michael_Oborne and @sibujacob.

1 Like