CoreMotion [ViewController updateReferenceAttitude:] - why is the selector not recognised?

Question

I’m new to CoreMotion. My first program shows deviceManager changing values for pitch, roll and yaw but crashes when it tries to set referenceAttitude

    - (void)updateReferenceAttitude
    {
        self.refAttitude = self.manager.deviceMotion.attitude;
        NSLog(@"you clicked a button that took a 3D snapshot");
    }

In debug, the statement in my method

    [myButton addTarget:self action:@selector(updateReferenceAttitude:) forControlEvents:UIControlEventTouchUpInside];

crashes with the following

    'NSInvalidArgumentException', reason: '-[ViewController updateReferenceAttitude:]: unrecognized selector sent to instance 0x14875a00'

To test it, I use Xcode 8.3.3 with an iPhone 5 C running iOS 10.3.3.

Can anyone explain why this selector is not recognised ?

Answer 1

The problem is fixed and had little to do with CoreMotion. The method

- (void)updateReferenceAttitude

should be

- (void)updateReferenceAttitude:(UIButton *(sender

I had included a UIButton to reset the reference attitude while the app is running but was calling the same method automatically after ViewDidLoad launches.

The problem was solved by using a statement for the initial reference instead of calling the method.

    if (self.refAttitude == nil)
    {
        self.refAttitude = self.manager.deviceMotion.attitude;  // initial run
        //        [self updateReferenceAttitude];
    }