LED blinking blue and yellow as soon as MAVROS initiates on companion computer

Hello guys

I’m running pixhawk 2.4.8, GPS module, and a companion computer connected through the usb. The companion computer is running MAVROS.

I had a very strange problem today:

  1. the pixhawk was powered on with blinking green light and healthy GPS lock.
  2. the companion computer was powered on at the same time, connected on through the USB.
  3. as soon as I start running mavros to read flight data from the pixhawk, the pixhawk LED switch to blinking yellow and blue, with no noise. The pixhawk would refuse to arm.
  4. as soon as mavros is killed, the pixhawk LED goes back to normal with blinking green.

The yellow and blue + noise suggest GPS issue, but there was no noise. There were no error messages. Does anyone know what is going on?

Thanks in advance!

@MCITYFC, if you have a log we can have a peek. My guess is that MAVROS was sending in position estimates and that made the EKF become unhappy.

If the vehicle refuses to arm there should definitely be a noise (if a buzzer is attached) and a text message should be sent to the ground station indicating the cause of the failure.

Hey there. The blinking blue and yellow was due to compass variance. I’m not sure how it’s related to running the mavros, as it flags the compass variance issue as soon as mavros was started. But if I waited long enough, the issue would correct it self. I wonder if there’s a RAM issue when the pixhawk is running mavlink?


This could happen if mavros is sending an external position estimate that includes a heading and if that didn’t match with the compass heading then the EKF would likely become unhappy and send higher compass variance values.