Question

I’m trying to make a simple app utilizing gyroscope, where a character moves according to the rotation of the iPad 1.

My code is not working, so I tested to see the values of raw,pitch,yaw,
and they actually stay as zero however I move the device.
I’m sure iPad 1 supports CMMotionManager, so I’m not sure what’s causing it…
My code is as follows

- (id) init{
if((self=[super init])){
    self.isTouchEnabled = YES;
    winSize = [[CCDirector sharedDirector] winSize];
    [self createRabbitSprite];

    self.motionManager = [[CMMotionManager alloc] init];
    motionManager.deviceMotionUpdateInterval = 1.0/60.0;
    if(motionManager.isDeviceMotionAvailable){
        [motionManager startDeviceMotionUpdates];
    }
    [self scheduleUpdate];
    //[self registerWithTouchDispatcher];
}
return self;

}

-(void)update:(ccTime)delta{
CMDeviceMotion *currentDeviceMotion = motionManager.deviceMotion;
CMAttitude *currentAttitude = currentDeviceMotion.attitude;

if(referenceFrame){
    [currentAttitude multiplyByInverseOfAttitude:referenceFrame];
}

float roll = currentAttitude.roll;
float pitch = currentAttitude.pitch;
float yaw = currentAttitude.yaw;

NSLog(@"%.2f and %.2f and %.2f",roll,pitch,yaw);

rabbit.rotation = CC_RADIANS_TO_DEGREES(yaw);

}

Please help me out..
and thanx in advance.

(edit)

Apparently, motionManager.isDeviceMotionAvailable is returning FALSE…
which must mean that iPad 1 doesn’t support CoreMotion???
Could it be something with the setting?

Answer 1

The iPad First generation does support CMMotionManager (as it has an accelerometer), but won’t return any gyroscopic data – it doesn’t have a gyroscope! You’ll need to check the gyroAvailable property of a CMMotionManager instance.