PPM with Pixracer

I’m not sure if this is an Arducopter issue or a hardware issue but specific issues with Pixracer have been adressed in Arducopter so I’ll ask. PPM input does not work. In my case its from an Orange LRS Rx but others have reported the same problem with other Rx’s. Works fine with Pixhawk, no go with Pixracer. Is this something that can be adressed with firmware?

PPM works for me with pixracer.
I’ve used both FrSky and DTFUHF.
That’s one thing that has never given me any trouble w/ the pixracer, so I don’t really have any advice other than be sure you’re using the correct port and wires.

Frsky works for me also with sbus. But I connect the same Rx that works no problem with Pixhawk (and APM for that matter) and no go on Pixracer. Same Rcin connection.

I am using Jeti PPM with Pixracer on a couple of quads, no problem.
Make sure you have the polarity, channels and speed set correctly.

Thanks Mike. It must be something with the protocol from the Rx but I still don’t understand why Pixhawk works and PIxracer (2 of them) doesn’t.

I had a similar issue using the LemonRX ppm rx with DX8 on pixracer.

The solution was to RESET all endpoints on your radio to default (100% travel).
The RX would then respond and show up under the rx configure tab in mission planner.

Initially I would get no response from the receiver config/calibration tab in Mission planner. RX powered up and bound ok.
I appears that i had my endpoints configured in my radio outside the parameters that the reciver could handle. I am used to setting the radio to 1000-2000ms per channel on miniquads running cleanflight with a serial spektrum sat rx. This does not appear to be compatible with PPM recievers on spektrum.
When everything in the radio travel range was reset to default everything started working.

Hope this helps.

I had a similar issue using the ARKBIRD ppm rx on pixracer.
And I build my own firmware form Git. I found this issue only to appear after 2016/10/15.
I could try all changed codes between 10/16~10/18 one by one to find it out.
If I found, I’ll report here.

We’ve got a few reports on this subject so Tridge is looking at it as a top priority.
Here’s the github issue in case people want to track the progress there: https://github.com/ArduPilot/ardupilot/issues/5112

I’ve reproduced the issue and pushed a fix to master
Here is a binary build for quad if anyone wants to test it:

1 Like

That build does fix the issue for me. I was able to calibrate my radio and arm the copter. Flight testing will have to wait until tomorrow but it sure looks good so far.


I updated the submodule to build new firmware and tested it.
It could fix this issue and work fine.
Thanks you very much! My drone could fly again.:slight_smile:

Excellent! It’s a small patch so we’re pushing out AC3.4.1 with this fix immediately. The build server takes about 4hrs to produce all the binaries for each board and frame combination we support but it’s on it’s way out in any case.

deleted, hardware issue.