how to get data from Core Motion on iOS

Question

i have trouble getting the accelerometer data from core motion manager...i followed the documentation and it still doesn't work :(

self.manager = [[CMMotionManager alloc] init];
self.manager.accelerometerUpdateInterval = 0.01;
[self.manager startAccelerometerUpdates];

CMAccelerometerData *newestAccel = self.manager.accelerometerData;

int x, y, z;
x = newestAccel.acceleration.x;
y = newestAccel.acceleration.y;
z = newestAccel.acceleration.z;

any help would be very much appreciated!!

Answer 1

I managed to make it work using blocks, here's the code that I managed to get working:

NSOperationQueue *theQueue = [[NSOperationQueue alloc] init];

_returnedData = [[CMAccelerometerData alloc] init];
_motionManager = [[CMMotionManager alloc] init];

[_motionManager startAccelerometerUpdatesToQueue:theQueue withHandler:^(CMAccelerometerData *accelerometerData, NSError *error) {

    _returnedData = _motionManager.accelerometerData;

    int x = _motionManager.accelerometerData.acceleration.x;
    int y = _returnedData.acceleration.y;

    NSLog(@"X: %i, Y: %i", x, y);
}];

You can either access the accelerometerData.accelleration directly from the CAMotionManager or by creating an instance of CMAccelerometerData and assigning the variables to that. Hope this helps.