How can I do it if I use COMPASS instead of ACCELEROMETER?

[ireneLiXR]

Hi, Zac
Actually, I am working on the AR and your ARKit program really inspires me a lot. I do a little change based on your program, but it has some problems.

First, the object I store is the different location with its own magnetic angle and name. I put them into a array and thier UIView with thier own location name in another UIView array.
In the function "updateLocation", I use my current magneticheading as a condition to get the corresponding UIView in the UIView array, but my program cannot update the UIView according to the if condition. it seems that my program cannot read the magneticheading if I add one new UIView....

Could you please give me some hints? Thanks