Finally, I got the answer to both questions. Here is the code I am using it. Hope it can help to someone.
MagneticField: .h
@property (nonatomic, retain) CLLocationManager *locationManager;
.m
@synthesize locationManager;
- (void)viewDidLoad
{
[super viewDidLoad];
// Starting compass setup
if(locationManager == nil)
locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.delegate = self;
//Start the compass updates.
if (CLLocationManager.headingAvailable) {
[locationManager startUpdatingHeading];
[locationManager startUpdatingLocation];
}
else {
NSLog(@"No Heading Available: ");
UIAlertView *noCompassAlert = [[UIAlertView alloc] initWithTitle:@"No Compass!" message:@"This device does not have the ability to measure magnetic fields." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[noCompassAlert show];
}
}
-(void)locationManager:(CLLocationManager *) manager didUpdateHeading:(CLHeading *)newHeading
{
NSLog(@"Magnetic value: %@", [[NSString stringWithFormat:@"%.1f", sqrt(newHeading.x*newHeading.x + newHeading.y*newHeading.y + newHeading.z*newHeading.z)] stringByAppendingFormat:@" µT"]);
}
Elevation: .h
@property (nonatomic, retain) CMMotionManager *motionManager;
.m
@synthesize motionManager;
- (void)viewDidLoad
{
[super viewDidLoad];
// Initializating MotionManager Object
motionManager = [[CMMotionManager alloc] init];
motionManager.showsDeviceMovementDisplay = YES;
motionManager.deviceMotionUpdateInterval = 20.0/60.0;
// Getting Elevation Value
CMDeviceMotionHandler motionHandler = ^ (CMDeviceMotion *motion, NSError *error) {
CMAttitude *a = motionManager.deviceMotion.attitude;
NSLog(@"Elevation value, %@:", [[NSString stringWithFormat:@"%.0f", a.pitch*180/M_PI] stringByAppendingFormat:@"˚"]);
};
[motionManager startDeviceMotionUpdatesUsingReferenceFrame:CMAttitudeReferenceFrameXTrueNorthZVertical toQueue:[NSOperationQueue currentQueue] withHandler:motionHandler];
}
Cheers.