Pixhawk Not Responding to Radio Cal & Strange Happenings

Need Help!

Purchased my second Pixhawk for another project and ran into a snag. I purchased a Spektrum AR8000 RX and paired it to my radio. I then connected it to the PPM module and wiring bundle exactly as I have for my other UAV (Y6). I also connected it to my Y6 frame and tested RX with Y6 Pixhawk and Radio. All checked good. I disconnected it and connected it to the new Pixhawk. I connected the Pixhawk to Laptop and uploaded the 3.1.3 stable version and flashed it to Pixhawk. I then went into Wizard and performed calibration of Compass and Accelerometers. Finished all calibrations up to Radio Cal. That is where I ran into a snag. It appears that the Mission Planner did not detect any movement of controls on my radio. I unplugged the USB cable, waited a few minutes then plugged it back in. Once I connected to mission planner I immediately went to Radio Calibration and noted for a few seconds I had input from radio which I observed. But approximately 10-15 seconds I noticed my radio calibration window indicated it was not observing any inputs from radio.

At this point my Pixhawk was unplugged and plugged back in and the main LED power firsts indicated a flashing Red/Blue sequence for a few seconds then a Yellow LED double flashing the remainder of the power on sequence. Figured the flashing yellow was the calibration was not completed.

I decided to go into CLI and this is where everything became weird to me. I unplugged and plugged Pixhawk to computer, connected in terminal window and observed that I did not actually see version 3.1.3 in the prompt but appears I’m only seeing the NuttX OS. I keep getting a bunch of OS commands and folders and a “nsh>” prompt.

I’m thoroughly confused as to what to do next and how to get the Pixhawk working correctly. At present the only items connect to Pixhawk it the safety switch and buzzer and 3DR compass/GPS along with the RX and PPM module.

Appreciate some help on this. Thank you.

Doug W

Ran a test from “nsh>” and this is what I received.
[attachment=2]Summary of Failure.jpg[/attachment]
[attachment=1]Sensor Test.jpg[/attachment]
[attachment=0]ADC and MTD Tests.jpg[/attachment]

So where do I go from here?

Hi Doug,

Please try to power the Pixhawk with a powered USB hub or with the power module, if you choose the last option and you have the Pixhawk connected to your vehicle motors, please remove the propellers first.

Also you can try to connect the Spektrum DSM satellite to the Pixhawk’s SPKT/DSM port?
copter.ardupilot.com/wiki/common … _RC_inputs

The conclusion to this issue is that after much TS, the problem lies with a bad Pixhawk RC input. Unit has been returned to manufacture and replacement sent out.

I’m having a similar problem, plugging in my paired receiver, does not show bars in calibration.

How did you run the nsh> test?