stop a scheduledTimer

hi, so the user must click the POWER ON button in order to share the location every 5s

Longitude and Latitude

@IBAction func power(_ sender: UIButton) {
            var helloWorldTimer = Timer.scheduledTimer(timeInterval: tiempou, target: self, selector: #selector(ConductorPrincipalViewController.sayHello), userInfo: nil, repeats: true)
    }

this is my #Selector

@objc func sayHello()
    {
        UserDefaults.standard.set(latitud.text, forKey: "latitudeConductor")
        UserDefaults.standard.set(longitud.text, forKey: "longitudConductor")
        let id = UserDefaults.standard.string(forKey: "idChofer")

        let request = NSMutableURLRequest(url: NSURL(string: "hehe")! as URL)
        request.httpMethod = "POST"
        let postString = "Id=\(id!)&Latitud=\(latitud.text!)&Longitud=\(longitud.text!)" //location send to DB
        request.httpBody = postString.data(using: String.Encoding.utf8)
        
        let task = URLSession.shared.dataTask(with: request as URLRequest) {
            data, response, error in
            
            if error != nil {
                print("error=\(String(describing: error))")
                
                
                return
            }
            
            print("response = \(String(describing: response))")
            
            let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
            print("responseString = \(String(describing: responseString))")
            
            
        }
        task.resume()
    }

everything is working fine.

But if the user decides not keep sharing the location

standBY buton

@IBAction func reposo(_ sender: UIButton) { 
        tiempou = 0.0
        UserDefaults.standard.set(latitud.text, forKey: "latitudeConductor")
        UserDefaults.standard.set(longitud.text, forKey: "longitudConductor")
        let id = UserDefaults.standard.string(forKey: "idChofer")
        
        let request = NSMutableURLRequest(url: NSURL(string: "hehe")! as URL)
        request.httpMethod = "POST"
        let postString = "Id=\(id!)&Latitud=\("")&Longitud=\("")" // the location is updated to ""(nothing)
        request.httpBody = postString.data(using: String.Encoding.utf8)
        
        let task = URLSession.shared.dataTask(with: request as URLRequest) {
            data, response, error in
            
            if error != nil {
                print("error=\(String(describing: error))")
                
                
                return
            }
            
            print("response = \(String(describing: response))")
            
            let responseString = NSString(data: data!, encoding: String.Encoding.utf8.rawValue)
            print("responseString = \(String(describing: responseString))")
            
            
        }
        task.resume()
    }

i had tried multiple things

i set a variable to overwrite the time as 0 instead of 5

var tiempou = 5.0

and when the user tap the standBY button

@IBAction func reposo(_ sender: UIButton) {
        tiempou = 0.0

time is changed to 0.0 but it doesn't work the location keeps sharing every 5s

Any ideas? 😕

my DidViewLoad in case need

override func viewDidLoad() {
        super.viewDidLoad()
        
       
     
        self.locationManager.requestAlwaysAuthorization()
        
       
        self.locationManager.requestWhenInUseAuthorization()
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        

        locationManager.startUpdatingLocation()
        
        if CLLocationManager.locationServicesEnabled() {
            locationManager.delegate = self
            locationManager.desiredAccuracy = kCLLocationAccuracyBest
            locationManager.startUpdatingLocation()
        }
        
        
        map.delegate = self
        map.mapType = .standard
        map.isZoomEnabled = true
        map.isScrollEnabled = true
        
        map.showsUserLocation = true
        
        
        if let coor = map.userLocation.location?.coordinate{
            map.setCenter(coor, animated: true)
            
        }
}