having issue with scrolling image with gyroscope

Question

I have a strange problem with iPad Air !!! , my code runs fine on iPad 3 , iPad 4 , iPhone 5S , iPod 5th Gen , but on iPad air , my image scrolls automatically without user

Answer 1

could you try the following: This adds the error handling to your code, as an error may be returning from the gyroscope, and this may return a value >0.09; Use NSLOG more often when testing to pick apart your code and see what values are returning.

@property (strong, nonatomic) CMMotionManager *motionManager;


self.mainScrollView.frame = CGRectMake(0, 0, self.view.frame.size.width,       self.view.frame.size.height);

self.mainScrollView.bounces = NO;


self.mainScrollView.userInteractionEnabled = NO;

//set up the image view
UIImage *image= [UIImage imageNamed:@"YOUR_IMAGE_NAME"];
UIImageView *movingImageView = [[UIImageView alloc]initWithImage:image];
[self.mainScrollView addSubview:movingImageView];

self.mainScrollView.contentSize = CGSizeMake(movingImageView.frame.size.width, self.mainScrollView.frame.size.height);


self.mainScrollView.contentOffset = CGPointMake((self.mainScrollView.contentSize.width - self.view.frame.size.width) / 2, 0);

//inital the motionManager and detec the Gyroscrope for every 1/60 second
//the interval may not need to be that fast
self.motionManager = [[CMMotionManager alloc] init];
self.motionManager.gyroUpdateInterval = 1/60;

//this is how fast the image should move when rotate the device, the larger the number, the less the roation required.
CGFloat motionMovingRate = 4;

//get the max and min offset x value
int maxXOffset = self.mainScrollView.contentSize.width - self.mainScrollView.frame.size.width;
int minXOffset = 0;

[self.motionManager startGyroUpdatesToQueue:[NSOperationQueue currentQueue]
                            withHandler:^(CMGyroData *gyroData, NSError *error) {
// IF NO ERROR ---
if(!error){
NSLog(@"No error from Gyroscope %f",gyroData.rotationRate.y);
     if (fabs(gyroData.rotationRate.y) >= 0.1) {
NSLog(@"Moving image");
        CGFloat targetX = self.mainScrollView.contentOffset.x - gyroData.rotationRate.y * motionMovingRate;

         if(targetX > maxXOffset)
               targetX = maxXOffset;
         else if (targetX < minXOffset)
               targetX = minXOffset;


         self.mainScrollView.contentOffset = CGPointMake(targetX, 0);
      }
}
// ERROR returned from GYRO
else NSLog(@"error recieved %@",error);
}];