Magnetometer seizing / breaking after 30 seconds?

[Hogster]

Hi all

I've got a strange problem with the magnetometer on my Hexacopter. I'm using a FFIMU0.4.3 and a Flyduino V1 board running MultiWii 2.1.

I've managed to calibrate the magnetometer fine, and rotating the vehicle around the yaw axis creates a corresponding movement of the compass needle in the GUI (and there's no / very little movement of the compass when I roll or pitch the vehicle). Initially, running up the motors caused the compass to move, so I have now separated my power distribution board and the sensor board and the interaction has gone.

However, if I leave the vehicle sitting on the ground for 30 seconds or so, the next time I pick it up, the compass behaves eratically, and also the magnetometer readings in the GUI have frozen. Restarting the Conf software (and thereby rebooting the flight controller), immediately fixes the issue, and the calibration is still perfectly valid (point it North, the compass indicates North, etc).

I assume this will also be happening in the air, so effectively the compass becomes useless after 30 seconds or so!

Any thoughts on how I could fix this?

Many thanks!


David

[wilco1967]

check your I2C wiring.....

I had exactly the same..... Already ordered a new 5883, but it turned out to be a cold solder joint on my GND wire on the 5883 that was fine when steady, but would cause errors when flying.... some errors were still ok, but after too many, it would quit.... After a reset, it would work again.

The new 5883 is still in the bag

[Hogster]

Hi wilco

Hmm I guess it could be a wiring issue. I will double check it the next time I have the Hex in front of me. It does seem odd that it goes from working to frozen whilst sitting on the ground, and then without touching / moving the Hex, a restart of the software repairs the fault. It's almost as if a buffer is filling up somewhere and then falling over ...? I guess it isn't a common problem or more people would be having it ...

Many thanks


David

[tovrin]

a crappy ground can absolutely cause very strange intermittent issues, especially ones that seem to resolve upon reset.