@BartLeonard sorry to hear about your accident. Did you have any luck connecting your receiver to the pixhawk (via the SBUS port) without the PWM board? (I do not have this hardware)
@Dave84
I received this same error but with the pix hawk 4 mini. My auto pilot never registered the receiver when attempting to plug into the mini’s Radio Control Receiver Input.
I asked the question here if you are interested in helping. http://discuss.px4.io/t/pixhawk-4-mini-and-x8r-not-working/9406
On the other hand, I was able to get my pixhawk 4 to recognize the same reciever via the SBUS port that BarLeonard originally tried to connect with. If you have any troubleshooting advice can you please help.
Thank you,
-Jordan