WTF - compass for ipad doesn't work.

[Lionel Mandrake]

I searched the Apple store for "compass" and found "free compass for ipad". I downloaded and installed it. It gives me a choice between "magnetic north" and "true north", but neither of these choices works properly. As I rotate the iPad, the arrow doesn't stay pointed even approximately north. Why?

[Old and In the Way]

1. Did you calibrate it?

Try moving the device in figure 8 motions in a horizontal plane. That should reset the sensor properly.

[Lionel Mandrake]

2. I tried that several times.

The "calibration" didn't help. Besides, it makes no sense.

The compass on my iPhone works just fine as long as it's roughly horizontal. There is no such thing as "calibration" for the iPhone.

What's the difference between the two compasses? If they both sense the Earth's magnetic field, then they should both stay pointed approximately north regardless of any motion.

[Old and In the Way]

3. I think it is a gps sensor, not a magnetic sensor. Nt

[Lionel Mandrake]

4. I think you're right.

I took the iPad outside for better GPS reception, and eventually the Compass app started to work properly, sort of. I know that some iPhones sense the Earth's magnetic field via the Hall effect. I guess my iPhone, but not my iPad, has a Hall effect sensor. The iPad must sense the direction of the GPS signals and must know where the satellites are. That's a more complicated and less reliable way to tell where north is. I still don't understand how the calibration works, but it seems to be necessary.

[Kablooie]

5. Here's what worked for me...

Go to:
Settings - Privacy - Location Services - System Services:
and turn off Compass Calibration.

Then the compass started working properly.
It's nuts I know but the compass refused to indicate north until I did this.

[Lionel Mandrake]

6. I tried that.

It didn't work for me.