Stable Release v1.11.3 DSM SRXL2 Receiver Incompatibility

PX4 Autopilot Drivers & Sensors 🔧
1

Hello all,

Although the release note of v1.11.3 declares as “… ensures that all DSM RC receivers are detected again.”, I am having an issue with my Spektrum SPM4650 DSMX SRXL2 receiver and Spektrum DX8 transmitter as below. I replicated the issue on both Pixhawk-4 and Hex Cube Black.

  • When all channel sticks are constant, Ch-2 jumps between different values
    1 2

  • Sometimes it detects a 9th channel although my transmitter is 8-channels.
    3

  • There is no change at the Channel Monitor’s indicators when I move the sticks and toggle switches of the transmitter

  • If I try to calibrate the radio, it can detect Full and Min Throttle. Then, it cannot detect my Yaw-Right command and not possible to proceed to the calibration.

  • As a side note, at the v1.11.2, the autopilot cannot detect any channel and gives the following error:
    4

Both releases work flawlessly with the obsolete Spektrum DSMX Quad Race receiver (SPM4648)

2

Hi @ozanyuceol,
I think the PX4 software is not supporting the SRXL2 protocol used by your receiver.
I stumbled on your message looking for some information about such a possibility, but right now I didn’t find anything in the code related to SRXL2 protocol

3

Hi @Nonn0,

Yes it seems so, however there should be some difference between v1.11.2 and v1.11.3 regarding to this. Because, as I mentioned, it was not able to detect the number of channels at v1.11.2 at all.