Wrong Throttle Channel for Rover

PX4 Autopilot Configuration & Flight Modes ⚙️
1

New to the group, been lurking for a while. I finally had the time chance and working parts to setup my rover.

I have a Pixracer, and I’ve just got it setup in QGroundControl. I was able to get my radio calibrated, and get manual mode working.

In the Radio configuration in QGC I can see the throttle move when i move my stick (channel 3) and Roll (channel 1). When I arm my rover the steering servo works great. The throttle isn’t setup correctly. The throttle does move when I move the channel 2 stick (though configured in reverse).

Two questions:

  • How do I ensure that that the throttle is correctly mapped to the 3rd channel of my Pixracer?
  • Is there support for moving the rover backwards? If so how do I configure that?

Config
Airframe Type: Rover
Vehicle: Axial Racing AX10
Firmware Version: 1.6.5dev

Actual Vehicle
Hobby Kick Desert Fox 1/10
Receiver: FRSky X4R
Transmitter: Turnigy 9X

Thanks!!

2

Any luck ? I am also starting off with px4 and rovers.

3

Net yet,
Though I was going to compare the differences between the Traxxas and Axial airframe templates. It looks like the Traxxas template gets a little more love in the doc.

Keep me posted on how you make out too!

4

First I think you want to start with the Traxxas Stampede configuration. It’s a little more complete as the Axial Racing is just passthrough.

Then go through what is and isn’t working and I can show you how to reverse particular servos outputs, or update the mixer.

1 Like
5

OK, had some time to try it out tonight. I switched over to the Traxxas Stampede. Similar problems. Though I was able to find the mixing files you hinted about:

I did have my output set wrong (I was using 1 and 2). I corrected this to use what was configured as 2 and 4.

Now my steering works but was not on the channel I was expecting, currently steering is based on the YAW radio channel.

Throttle does not work at all.

I had spent a lot of time trying to figure out what I was missing for mixing in the Parameters so, I’m kind of happy to have found the above files, but still confused.

My car is technically 4wd, but it only has front steering so I’m assuming that configuration should the the same between the Traxxas and my setup. Same for the throttle though. (cars are basically just two channels anyway)

Any idea what I’m missing? I’m happy to dig around if you point me in the right direction.

6

Just figured out the throttle, I needed to ARM, the servo was moving previously so I assumed it was already armed.

This is great!! So two things left:

  • Servo channel seems wrong (see previous message)
  • Is forward and reverse supported for rovers?
7

Did you solve the forward and reverse problem about rover? I have same problem that is no reverse.