[closed] Incorrect Compass Heading

[Guest]

App: Offline Maps 2.0
Phone: Note 4 KitKat 4.4.4

I noticed recently that the compass is displaying the wrong heading direction, by about 18 degrees. I am unsure if this problem existed before the recent update. I downloaded AlpineQuest to test the compass out, and that seems to be giving the correct compass heading. AlpineQuest also agrees with this other GPS app I tried.

I saw that the declination is different between Offlinemaps and AlpineQuest, by around 18 degrees. It seems like this is where the issue lies. Is there anyway to adjust this value or have it be calculated correctly? I tried changing the sensor and rotating the phone around 360 degrees in various directions to try and calibrate it.

Here is some screenshots.
http://imgur.com/a/Oir74

Thanks! Let me know if you need more information

[Psyberia-Support]

Hi and thanks for your report.
Yes you're right, it seems that the incorrect heading comes from the magnetic declination.

This computation is not really clear (it's in the online help but not so visible), so here are more explanations about it:

In order to compute the magnetic declination, the application needs the current user location (since the declination depends on the location on the Earth).
The app will first have a look in the "last known location of the device" given by the Android system. If this location is not known, then the application will use the screen center location. I agree it's a bit risky, but doing this allows users with a GPS-free device to still get a precise magnetic declination (and users usually look at a place around their location when using the compass anyway).

So, to update the magnetic declination, just move the map on your (approx.) current location (or better, activate the GPS Location to get your real location), restart the application, and turn on the compass again.

Let me know if it's not fine.
Best regards

[Guest]

Awesome! Thanks for the help, I got it working. I did have my location on throughout the whole time and I restarted my phone even.
It seems like the issue did not clear up until I cycled location off/on. Also, I was in GPS only mode.

[Psyberia-Support]

Ok great if it's fine now.
Thanks for the feedback.
Best regards