Gyro.swift

let motionManager = CMMotionManager() // Class variable, otherwise ARC will delete the object        

if motionManager.isGyroAvailable {
    if !motionManager.isGyroActive {
        motionManager.gyroUpdateInterval = 1.0 / 2.0
        motionManager.startGyroUpdates(to: .main, withHandler: { (gyroData, error) in
            if let gyroData = gyroData {
                print(String(format: "%.02f %.02f %.02f", gyroData.rotationRate.x, gyroData.rotationRate.y, gyroData.rotationRate.z))
            } else if let error = error {
                print("1Error \(error.localizedDescription)")
            } else {
                print("2Error")
            }
        })
    } else {
        print("isGyroActive = true")
    }
} else {
    print("isGyroAvailable = false")
}