Inaccurate magnetometer readings

[Stu2009]

Magnetometer reads anywhere from 350 to over 650uT, constantly fluctuating. Earth background is normally 50uT
2 apps that have magnetometers..".Accurate Compass" by Stonekick and the compass within "Smart Tools" by Smart Tools Co

Compass will point in any direction and is not dependent on attitude of Nexus 7, vertical, horizontal on a slant, does not matter, the function is always inaccurate will never read correct North
Tried several compass apps... all will not work correctly
Tried removing and reinstalling apps with the same problem
The high readings are always there, from inside the house to the middle of a field
Other programs that will not work...Google Sky Map
I have tried to cure by turning off all radio functions, BT, WiFi & GPS, no difference in readings!
Any Suggests accepted. In anticipation...Thanks for a reply

 

[sparksd]

Those magnetometer readings would seem to indicate that you are either near a source of interference or your magnetometer itself has problems. Given your tests, it appears the latter. My magnetometer reads about -47uT in the Z axis and a compass app works reasonably well if I first calibrate by slow rotations around the X, Y, & Z axes. I have a case with the magnetic strip but it does not appear to have significant effect - results are the same when I leave it off for extended periods.

A longer discussion over at Issue 36678 - android - Nexus 7 tablet compass issue - Android Open Source Project - Issue Tracker - Google Project Hosting

Dave

 

[Stu2009]

Hi Dave
Thanks so much for the reply and link....I am sooo happy to hear I am not the only person having problems. Read the link and am going to post my observations there also. I guess the problem is more wide spreed than just my Nexus 7. Since my first post, I did a factory reinstall, and that did not fix the problem.
Thanks again
Stu