RC radio calibration, Detected 0 radio channels. To operate PX4, you need at least 5 channels

I have a pixhawk 3 PRO and have not been able to do RC radio calibration. I get this message “Detected 0 radio channels. To operate PX4, you need at least 5 channels” wondering if this issue has been solved or how it can be fixed? it looks like some kind of HW problem?. Any help will be appreciated thanks.

  • What make and model is your receiver (Rx) and transmitter (Tx)?
  • Is your Rx bound to your Tx?
  • Is your Rx SBUS capable?
  • Does your Rx have a separate power supply (not from the Pixhawk)?
  • Do you have the SBUS from your Rx connected to RCIN on the Pixhawk?
  • Confirm the polarity of the SBUS cable from the Rx to the Pixhawk.
  • I have a Futaba Rx R7008SB (Sbus/PWM) and a T14SG Futaba Tx.

  • Yes Rx and Tx are already linked.

  • Rx powers on when I plug the pixhawk via USB to a laptop.

  • Yes it is connected to RCIN port on the pixhawk.

what I am missing is a PPM/PWM decoder and maybe it is causing this issue?

  • Try using SBUS2 ?
  • Try the other channel modes of the Rx, i.e. Mode C?
  • Try using a separate 5v source to power the Rx.
  • If the SBUS is working, you shouldn’t need a PPM Decoder. You can try using one just to check.

Good luck.

I have the same problem with a Taranis Plus and an X8R receiver binded in Mode 4 with only an SBus connection (single, power & ground) to the RC In connector on a Holybro Pixhawk 4 Mini. I also noticed the GPS switch on the Holybro GPS assembly does not light. It is powered by a Holybro PM02 power converter on the power cable.

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I posted a similar question here. http://discuss.px4.io/t/pixhawk-4-mini-and-x8r-not-working/9406 Have you had any luck @steveb?