RFD 900x Telemetry Issues w/ QGroundControl/Mission Planner

Hello! My name is Ethan Roe, and I am a student at Indiana State University. I am emailing you because we are in an Unmanned Systems Mechanics class, and are building a quadcopter with the stock Pixhawk Cube and the RFD900X. I have CC’d my instructor, my 2 TA’s, and my other group members.

We have not been able to enable the RC functionality of the modem. We attempted to change baud rate, but were unsuccessful in Mission Planner. We were attempting to find the setting based on a tutorial on the Pixhawk website but were not able to because the setting was not present in the program. We weren’t able to do a loop-back test because of hardware limitations. We weren’t actually able to configure the hardware to perform the test safely. We also tried updating both modems to the 3.07 firmware as we were advised to by RFDesign, the manufacturer that made the RFD 900x.

We are currently engaged in a quadcopter build, with a pixhawk cube and the RFD900X and the Spektrum FPV Racing Serial Receiver. Our issue is that in Mission Planner and QGroundControl, we are unable to receive any telemetry information, and are unsure where our actual issue is. We have posted on several forums, and looked at different pinouts for the cube and the RFD900x, but have yet to find anything that can resolve the issue.

Any help is greatly appreciated!

When you power the RFD900 after a few second what is the red and green LED behavior?

Have you posted to discuss.ardupilot.org?
First two things I’d check: reset both radios to defaults, and make sure the air radio is powered separately from your autopilot (not via the telemetry port).