GPS / serial errors on pixhawk

I’ve been trying to get my pixhawk working with a basic ublox 6 GPS receiver.

I get a good GPS lock when i am disarmed and on the ground. I can swap to GPS flight modes on the ground while disarmed and i get confirmation via the LED and also via my phone across bluetooth.

As soon as i arm and take off all the GPS flight modes stop working.

Here’s a log file with error messages; … 3d6fdf#gps

I have reset everything to defaults several times, reflashed plane then copter firmware to ensure everything is wiped, no change in behavior.

Here’s a screenshot of my terminal;

I am a little bit worried about the nonesense characters that are present. I get about 3 or 4 every few seconds that interupt my typing and prevent my using the terminal.

I get the same nonsense characters via the terminal even with all serial devices including GPS and bluetooth removed.

Have i broken my pixhawk somehow?

I have replaced the pixhawk and GPS unit and am getting the same errors. I cannot use any GPS flight modes anymore despite having set up the flight modes and gone through the wizard (multiple times).

If I am on the ground and disarmed I can enter GPS flight modes and get confirmation from my phone across bluetooth telemetry that the flight mode has engaged (it says ‘loiter’).

As soon as I arm and spin up the motors if I try to enter the GPS flight modes I get a ‘Beebop’ noise from the pixhawk speaker and no confirmation across bluetooth on my phone. Altitude hold and stabilise flight modes work fine but I cannot get any of the GPS flight modes to engage.

Is it actually possible to enter a GPS flight mode with the aircraft on the ground armed with the motors spinning but the props off in order to test? I haven’t got flying weather at the moment and if the answer is no i’ve just wasted the last week.

Does anyone have any suggestions on what I could be doing wrong? I have rebuilt the aircraft and electronics multiple times with 2 different pixhawks and keep getting the same GPS error.

Here’s another log file; … 3d7007#imu

you have fix on only 7 GPS satellites, good it refused , or you would have a DJI moment.
-remember to learn to fly (in stabilize mode)