QGC vehicle set up compasses inconsistent

Blue Robotics Software QGroundControl
1

Heyo,
I’m calibrating my BlueBoat compass in Qgroundcontrol, and after scouring the forums for solutions keep running into a PreArm: Compasses inconsistent error!

I’m doing the calibration in a soccer field so it cant be interference?? Compass 1 (IST8308 (I2C6)), and Compass 2 (MMC5883 (SPI1)), are in green, but Compass 3 (AK09915 (I2C1)), is always mid yellow after the calibration. The actual location in Qground control is accurate to within a few meters when I see the blueboat on the main page but I always have the error. I have tried to deselect use of the compass, but to no avail.

I have autopilot rotation set to Roll 180, and have compass 1 (external) set to pitch 180 as is in the guide. However I have played around with the orientation of compass 3 (which doesn’t have an orientation option in the guide? and is also an external compass) from roll 180, pitch 180, or none.

Still getting the same issues…I’ve found that it may be caused by the internal and external compasses pointing in the wrong directions? so hoping someone has had this issue and can help, and that its just a matter of selecting a different orientation from the drop down??
Also running ardupilot firmware version 4.5.1 (stable), and OS version 1.2.5 if those might be causing issues?

Cheers
Alex

2

I have tried a loading some older ardupilot firmware versions, and some older BlueOS versions with no luck. Going to attempt to load Blueos 1.3.0 beta 3. I notice that compass 1 and 3 are external, while only compass 2 is internal. In vehicle setup guide compass 3 is listed as internal but thats the only thing I can thin of thats off…

3

Did not work, and still attempting to fix so any help is appreciated!

4

Determined it was a battery issue, there was some form of induction from the battery that caused the GPS to be off. I simply moved the battery to the other hull and the error was gone??

5

Hi @Alex_Whitworth -
That’s very unusual! I would bet that it was not the battery, but the placement of the cable coming from it. This should be routed under the battery, in the keel of the hull, so that the magnetic fields from the flowing current do not affect the magnetometer due to close proximity. Using only one battery may intensify this affect as more current is flowing than in the parallel case.
It’s also recommended to operate the BlueBoat with at least two batteries, as this puts the hulls in balance. From the operators guide:

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