Well, if it operates using magnets, then it stands to reason that anything that produces a magnetic field would affect it...
Take a REAL compass and check around. See if it's actually your iPhone or if it is just a magnetic field.
I'll tell you, I wasn't impressed driving today while tracking on the map. That thing must be picking up a ton of interference in the car or something. The map was just randomly spinning all over the place while never locking into my direction. I was on I-290/I-355 headed south. Maybe from other cars and trucks? Nice to see where all the traffic hot spots were at least, but man, the compass part really made the map unusable!
Tests in my office here or taking a long walk yielded perfect compass results though.
Magnetic interference decreases with the square of the distance. Unless the sensor is lab grade equipment, the interference is coming from something close by.
Like car stereo speakers perhaps?
That's a really good guess. I can't think of any other car parts that contain powerful magnets.
But, the speakers are usually hidden, on the bottom of doors and such. I find it unlikely that there would be a speaker located at the same place as someone would put their phone. And, if they're using the phone, they're probably holding it, so it would be far enough from the magnets not to affect it.![]()
The phone was probably a good 2 feet from the closest speaker, maybe 5 feet from the furthest?
Take a REAL compass and check around. See if it's actually your iPhone or if it is just a magnetic field.
Anything that would affect an iPhone's compass would affect a real compass, no?
That was kind of the point, no?
Welcome to the ancient world of compassesCompasses need regular calibration to take interference in to account, and exhibit indication errors and lag due to turning and acceleration, etc. Even Apple's own knowledge base says
The digital compass should only be used for basic navigation assistance and should not be solely relied on to determine precise locations, proximity, distance, or direction.
I think it's more suitable for handheld use on the street. When in the car your GPS app will provide a more useful and consistent reading.
You would have to think someone is pretty stupid to point out a compass will be drawn to a magnetic source. A little more helpful I would think would be a discussion of where the compass isn't useful and perhaps what could be done with that...
...Outside though? Works fine. And that's what counts.
Welcome to the ancient world of compassesCompasses need regular calibration to take interference in to account, and exhibit indication errors and lag due to turning and acceleration, etc. Even Apple's own knowledge base says
The digital compass should only be used for basic navigation assistance and should not be solely relied on to determine precise locations, proximity, distance, or direction.
I think it's more suitable for handheld use on the street. When in the car your GPS app will provide a more useful and consistent reading.