I have an ArduPilot Mega 2.6 (although I think it’s probably a 2.5.2, as I needed to cut the compass SDA line?)
My GPS module is the uBlox NEO-6M.
My two symptoms / configurations;
With the uBlox GPS/Compass disconnected, the ‘current heading’ seems accurate & stable, and moves accurately with rotation of the plane - which doesnt make any sense, because I have cut the onboard compass circuit?
- perhaps I havent cut deeply enough?
- I dont know if this is just some clever estimation of heading by use of PC link & gryo sensor?
- When in this configuration, I cannot run the compass calibration, no data points are seen.
With the uBlox GPS/Compass connected, it is then possible to run the Compass calibration, I get a good GPS 3D fix, the calibration goes smoothly, with 900+ datapoints in all axis, but when returning to the ‘Flight data’ screen, the ‘Current heading’ sometimes seems to be in line, but very quickly starts to disappear off on it’s own journey to pretty much any compass point - although it seems to favour 90deg to plane.
Is there something I’m missing?
I do have a magnetic door latch about 3-4 inches away from the uBlox, which feels like a pretty strong magnet… could this be related?
I also have a volage regulator nearby (5v for APM), which has a ferrite ring with the wire wrapped around it… can this cause magnetic interference?
Otherwise there isnt much else nearby, other than Rx & APM - both a good 3 inches away.
Hope you can help!