iOS Motion Detection: Count of times the device moves up and down

Question

How can i use the gravity or motion sensors inside iPhone to calculate how many times the device moved up and down. e.g. as if it were lifted like a dumbbell for a couple of times, i wanted to count it.

Forgive me if this is something very simply achievable but I'm pretty new to iOS development and hence the question.

Answer 1

You need to use the Core Motion framework to access the gyroscope and accelerometer data.

let manager = CMMotionManager()
if manager.gyroAvailable {
  // CMMotionManager is available.
  manager.gyroUpdateInterval = 0.1
  manager.startGyroUpdates()

  // get gyro data...
  let queue = NSOperationQueue.mainQueue
  manager.startGyroUpdatesToQueue(queue) {
     (data, error) in
     // ... get data here
  }
}

// accelerometer data
if manager.accelerometerAvailable {
   manager.accelerometerUpdateInterval = 0.01
   manager.startAccelerometerUpdatesToQueue(NSOperationQueue.mainQueue()) {
      [weak self] (data: CMAccelerometerData!, error: NSError!) in
      // get data here ...
   }
}

Combining those 2 you can get the detection going. Experiment with the results until you get the right motion you want.