private async void Sensor_ValueChanged(object sender, TemperatureChangedEventArgs e)
        {
            await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, async () =>
            {
                tbkValue.Text = String.Format("{0:F02} °C", e.Temperature);

            });

        }
        // An event handler that runs when a "sensor.ValueChanged" event is triggered in SensorSource
        private async void Sensor_ValueChanged(object sender, TemperatureChangedEventArgs e)
        {
            await Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal, async () =>
            {
                // Changes the value on MainPage to display the new temperature
                tbkValue.Text = String.Format("{0:F02} °C", e.Temperature);

                if (hub == null) return;
                try
                {
                    // Executes a method "newUpdate" on the server side hub asynchronously, with params of type Object[]
                    // (notifies clients that sensor has a temperature change)
                    await hub.Invoke("newUpdate", new object[] { "TEMP_CHANGED", e.Temperature });
                }
                catch { }

            });
        }