Using my own class DeviceOrientationHelper to determine device orientation based on accelerometer motion data readouts

ViewController.swift

import UIKit

class ViewController: UIViewController {
    
    private var deviceOrientationHelper = DeviceOrientationHelper()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        deviceOrientationHelper.startDeviceOrientationNotifier { (deviceOrientation) in
            self.orientationChanged(deviceOrientation: deviceOrientation)
        }
    }
  
    override func viewDidDisappear(_ animated: Bool) {
        deviceOrientationHelper.stopDeviceOrientationNotifier()
      
        super.viewDidDisappear(animated)
    }

    private func orientationChanged(deviceOrientation: UIDeviceOrientation) {
    ...
    }
}