Real time chart update in iOS application

I am creating an inertial sensors application where the values from three axis of gyroscope will be displayed on a line chart. I am using this https://github.com/danielgindi/Charts library for the chart implementation.
I have managed to show the values on the chart but the chart stops behaving normally say after 4,5 seconds and does not show the values correctly. Sometimes just the flat line even when i am moving the device and sometimes spikes in the data even when the device is stationary.
Could anyone please let me know where i am making a mistake. Thanks
Here is the code i am using.

Code Block 
import UIKit
import Charts
import CoreMotion
class ViewController: UIViewController ,ChartViewDelegate{
    @IBOutlet var lineChartView: LineChartView!
    
     var motion = CMMotionManager()
    var xAxisArray : [String]?
    var yAxisArray : [Double]?
    var date : NSDate?
    var dateFormatter : DateFormatter?
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        myGyroscope()
        //charts
        self.lineChartView.delegate = self
        let set_a: LineChartDataSet = LineChartDataSet(entries:[ChartDataEntry(x: Double(0), y: Double(0))], label: "x")
        set_a.drawCirclesEnabled = false
        set_a.setColor(UIColor.blue)
        let set_b: LineChartDataSet = LineChartDataSet(entries: [ChartDataEntry(x: Double(0), y: Double(0))], label: "y")
        set_b.drawCirclesEnabled = false
        set_b.setColor(UIColor.green)
        
        let set_c: LineChartDataSet = LineChartDataSet(entries: [ChartDataEntry(x: Double(0), y: Double(0))], label: "z")
        set_c.drawCirclesEnabled = false
        set_c.setColor(UIColor.red)
        self.lineChartView.data = LineChartData(dataSets: [set_a,set_b,set_c])
        
        
        let leftAxis = lineChartView.leftAxis
        leftAxis.labelTextColor = UIColor(red: 51/255, green: 181/255, blue: 229/255, alpha: 1)
        leftAxis.axisMaximum = 10
        leftAxis.axisMinimum = -10
        leftAxis.drawGridLinesEnabled = true
        leftAxis.granularityEnabled = true
        
        lineChartView.animate(xAxisDuration: -1)
        
    }
    
    // add point
    var i = 0
    @objc func updateCounter(x:Double,y:Double,z:Double) {
        
        self.lineChartView.data?.addEntry(ChartDataEntry(x: Double(i), y:x), dataSetIndex: 0)
         self.lineChartView.data?.addEntry(ChartDataEntry(x: Double(i), y:y ), dataSetIndex: 1)
         self.lineChartView.data?.addEntry(ChartDataEntry(x: Double(i), y:z), dataSetIndex: 2)
        self.lineChartView.setVisibleXRange(minXRange: Double(1), maxXRange: Double(50))
        self.lineChartView.notifyDataSetChanged()
        self.lineChartView.moveViewToX(Double(i))
    }
    
    func myGyroscope() {
        motion.startGyroUpdates(to: OperationQueue.current!) { (data, error) in
            
            if let trueData = data {
                self.view.reloadInputViews()
    
                let x = trueData.rotationRate.x
                let y = trueData.rotationRate.y
                let z = trueData.rotationRate.z
                self.i += 1
                self.updateCounter(x: x, y: y, z: z)
                
                
               
            }
        }
    }
    
}