Android Question Serious malfunction of a timer ?

    Private lastTime As Long
    Private TimerRegistra As Timer
    
    lastTime = DateTime.Now
    TimerRegistra.Initialize("TimerRegistra", 1000) 'Now the interval is 1 second, but you can adjust the value.
    
Sub TimerRegistra_Tick
    If DateTime.Now - lastTime >= 30000 Then
        'registra l'ultima GPS-Location
        lastTime = DateTime.Now
    End If
End Sub

#Region  Service Attributes
    #StartAtBoot: False
#End Region

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'These variables can be accessed from all modules.
    Dim GPS1 As GPS
    Dim Accuracy As Float
    Dim Altitude As Double
    Dim Bearing As Float
    Dim Latitude As Double
    Dim Longitude As Double
    Dim LogData As String
    Dim N As Notification
    Dim Speed As Float
    Dim Sats As Int
    Dim GPSAltitudeSeaLevel As Double
    Dim GPSNMEASpeed As Double
End Sub

Sub Service_Create
    N.Initialize
    N.OnGoingEvent = True
    N.Sound = False
    N.Vibrate = False
    N.Light = False
  N.Icon = "icon"
  N.SetInfo("ODYSSEY", "GPS-Service", "")
  N.Notify(1)
End Sub

Sub Service_Start (StartingIntent As Intent)
    GPS1.Initialize("GPS")
    If GPS1.GPSEnabled = False Then
      ToastMessageShow("GPS ON ?", True)
       StartActivity(GPS1.LocationSettingsIntent) 'Will open the relevant settings screen.
  Else
    GPS1.Start(0,0) 'Listen to GPS
  End If
End Sub

Sub Service_Destroy
    GPS1.Stop
    StopService("")
    N.Cancel(1)
End Sub

Sub GPS_LocationChanged (Location1 As Location)
    If Location1.AccuracyValid = True Then
        Accuracy = Location1.Accuracy
    End If
    If Location1.BearingValid = True Then
        Bearing = Location1.Bearing
    End If
    Latitude = Location1.Latitude
    Longitude = Location1.Longitude
End Sub

Sub GPS_NMEA (TimeStamp As Long, Sentence As String)
    If Sentence.SubString2(0, 6) = "$GPGGA" Then
        Dim vals() As String
        vals = Regex.Split(",", Sentence)
        If IsNumber(vals(9)) Then
            GPSAltitudeSeaLevel = NumberFormat2(vals(9),1,0,0,False)
            If GPSAltitudeSeaLevel > 0 Then
                Altitude = GPSAltitudeSeaLevel
            Else
                Altitude = 0
            End If   
        End If
    End If
    If Sentence.SubString2(0, 6) = "$GPRMC" Then
        Dim vals() As String
        vals = Regex.Split(",", Sentence)
        If IsNumber(vals(7)) Then
            GPSNMEASpeed = vals(7)
            Speed = GPSNMEASpeed * 0.5144444444
            If Speed <1 Then
                If Speed >0 Then   
                    Speed = 0
                End If
            End If
        End If
    End If
End Sub

Sub GPS_GPSStatus (Satellites As List)
    Sats = 0
    For i = 0 To Satellites.Size - 1
        Dim Satellite As GPSSatellite
        Satellite = Satellites.Get(i)
        If Satellite.UsedInFix = True Then
            Sats = Sats +1
        End If   
    Next
End Sub