"No INS backend available", when running APMRover 2


I received my Navio board today and I am working through the examples and tutorials.
While the ACCGyroMag example runs fine, the APMRover build I did does not. It starts waiting for a connection, upon connect from the GCS, it accesses the spidev0.0 (GPS) and then quits with the error “No INS backend available”.
If I try and run the ACCGyroMag example after that, it displays all zeros.
It only works again after a reboot.



It seems the whole SPI bus stops working after I execute the ardurover2.elf and it quits. GPS is also only accesible again after a reboot.

Hello Sebastian,

APM disables alternative functions for SPI chip select pins and drives them directly, that’s why SPI examples won’t work after running APM.

When you see the message “No INS backend available” then it is possible that Ublox chip select has been driven low (active) by Raspbian, and since support for Ublox SPI device hasn’t been added to APM yet it doesn’t disable that chip select resulting in MPU9250 and Ublox working at the same time. To ensure that it doesn’t happen you can manually set Ublox chip select pin (it’s GPIO10) to OUTPUT mode and write 1 to it before running APM.
This issue will go away as soon as we finish the Ublox SPI driver for APM.

Would this work?

GPIO.setup(10, GPIO.OUT)
GPIO.output(10, 1)

Or complete as this

import RPi.GPIO as GPIO  
GPIO.setup(10, GPIO.OUT)  
GPIO.output(10, 1)

We’ve already fixed chip select issue, so you can pull new stuff from emlid/ardupilot repo, navio or navio-experimental branches.

2014-11-08@14:02PM CST
RPi v.B
Raspbian-SEP-2014-RT-B+.img.tar.bz2 image installed
Both apt-get update and upgrade show already up to date
git pull in ardupilot, navio, and Navio folders show already up to date

I am still going into /ardupilot/arduplane, typing make configure, then make navio.
Output eventually shows arduplane.elf is in the /tmp/…build folder.
Typing sudo ./ArduPlane.elf -A udp: outputs
"Opened /dev/spide0.0"
"No INS backends available"
Same as before, and I am not running the above .py anymore. I have just reproduced it again after a fresh reboot after update,upgrade,git-pull

If I omit everything after -A it shows

pened /dev/spidev0.0  

Init ArduPlane V3.1.2beta1 (07975ed5)  

Free RAM: 4096  
load_all took 99us  

Press ENTER 3 times to start interactive setup  

þ3ýBeginning INS calibration; do not move planeWÚNo INS backends available  
MPU9250: unexpected WHOAMI 0xFF

Did you switch to the navio or navio-experimental branch by using ‘git checkout navio’?

That was the problem, connects now. Thanks.

I had the same message after starting apm. The thread says the GPIO issue has been fixed in 2014. There must be another issue?

Yes, I suppose it’s unrelated to this issue. I’d like to kindly ask you to open a new thread with the results of these actions:

  • Output of AccelGyroMag
  • Output of i2cdetect -y 1
  • A photo how’s everything connected. To ensure it’s not a connection problem, please, refer to this entry on how to attach your Navio to Raspberry Pi.

I’ll close this thread right away. Waiting for your response!