Chip 2004 October/CMCD1004.ISO/Software/Shareware/Programare/gpssdk/GPS.NET Global Positioning SDK 1.4.6.msi/Data1.cab/MainForm.vb5

Text File | 2004-08-25 | 40.5 KB | 791 lines

' **************************************************************************
' ****
' ****   GpsReceiver.NET Global Positioning SDK Example 1
' ****   A demonstration of GpsReceiver.NET's major features.
' ****
' ****   For assistance with your GPS device or for troubleshooting:
' ****
' ****          http://www.gpsdotnet.com/support
' ****          [e-mail]
' ****
' ****   To view known product issues & updates in the Knowledge Base:
' ****
' ****          http://www.gpsdotnet.com/kb
' ****
' ****   For pricing information & online ordering:
' ****
' ****          http://www.gpsdotnet.com/purchase
' ****
' ****   This source code is considered public domain and may be re-used
' ****   in your own applications.
' ****
' *************************************************************************
' ****
' ****   NOTE: Since GpsReceiver.NET is multi-threaded, the Invoke() method is
' ****   used frequently to make sure that updates to form controls occur
' ****   on the form's thread.  This prevents the application from locking.
' ****   up, especially for Compact Framework apps.  For more information,
' ****   refer to the Knowledge Base.
' ****
' *************************************************************************

Imports StormSource.Gps

Public Class MainForm

#Region " Starting the GPS Service "

    Private Sub StartButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles StartButton.Click
        ' Set the COM port to the numeric portion of the selected item in to combo box
        GpsReceiver.Device.Settings.ComPort = ComPortComboBox.Value
        GpsReceiver.Device.Settings.BaudRate = BaudRateComboBox.Value
        ' NOTE: It's important to add error checking around the Start() method and Enabled property
        Try
            ' Set the license key (which will suppress the trial "nag" screen)
            ' GpsReceiver.SetLicenseKey("[insert your license here]")
            ' Start receiving messages
            GpsReceiver.Start()
        Catch ex As UnauthorizedAccessException
            ' The trial screen was cancelled
            MessageBox.Show(ex.ToString, "Cannot Continue Trial", MessageBoxButtons.OK, MessageBoxIcon.Error)
        Catch ex As GpsException
            ' Notify of the error
            MessageBox.Show(ex.ToString, "Unable to Begin GPS Communications", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
        End Try
    End Sub

    ' Raised just before a connection attempt is made
    Private Sub GPS_Connecting(ByVal sender As Object, ByVal e As DeviceSettingsEventArgs) Handles GpsReceiver.Connecting
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Connecting to GPS device...")
    End Sub

    Private Sub GPS_Connected(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.Connected
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Connected to GPS device, please wait...")
        ' Enable the Stop button, disable the Start button
        Me.Invoke(New EventHandler(AddressOf EnableStopButton))
    End Sub

    ' Invoked from the GpsReceiver.NET thread to enable the stop button
    Private Sub EnableStopButton(ByVal sender As Object, ByVal e As System.EventArgs)
        StopButton.Enabled = True
        StartButton.Enabled = False
        BaudRateComboBox.Enabled = False
        ComPortComboBox.Enabled = False
    End Sub

    Private Sub GPS_Acquiring(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.Acquiring
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Please wait while satellite information is gathered...")
    End Sub

    ' Raised when the receiver has adjusted the baud rate in an attempt to receive GPS information
    Private Sub GPS_BaudRateChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.BaudRateChanged
        Select Case GpsReceiver.Device.Settings.BaudRate
            Case 4800
                Me.BaudRateComboBox.SelectedIndex = 0
            Case 9600
                Me.BaudRateComboBox.SelectedIndex = 1
        End Select
    End Sub

    Private Sub GPS_Timeout(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.Timeout
        MessageBox.Show("The GPS device did not respond to commands, even after attempts to detect the correct connection settings.  The device may be powered off.  Try restarting the Receiver.", "GPS Device Timeout", MessageBoxButtons.OK, MessageBoxIcon.Hand)
    End Sub
#End Region

#Region " Stopping the GPS Service "

    Private Sub StopButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles StopButton.Click
        GpsReceiver.Stop()
    End Sub

    ' Raised just before an attempt is made to disconnect from the GPS device
    Private Sub GPS_Disconnecting(ByVal sender As Object, ByVal e As DeviceSettingsEventArgs) Handles GpsReceiver.Disconnecting
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Disconnecting from GPS device...")
    End Sub

    ' Raised when the connection with the device is now closed
    Private Sub GPS_Disconnected(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.Disconnected
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Disconnected from GPS device.")
        ' Reset start & stop buttons
        Me.Invoke(New EventHandler(AddressOf EnableStartButton))
    End Sub

    ' Invoked from the GpsReceiver.NET thread to enable the stop button
    Private Sub EnableStartButton(ByVal sender As Object, ByVal e As System.EventArgs)
        StartButton.Enabled = True
        PowerOffButton.Enabled = False
        DownloadWaypointButton.Enabled = False
        EditWaypointButton.Enabled = False
        NewWaypointButton.Enabled = False
        StopButton.Enabled = False
        BaudRateComboBox.Enabled = True
        ComPortComboBox.Enabled = True
    End Sub

#End Region

#Region " Demonstration of Motion-Related GPS Events "

    ' Updates the current speed
    Private Sub UpdateSpeed(ByVal sender As Object, ByVal e As SpeedEventArgs)
        ' Are we using the Imperial or Metric system?
        If System.Globalization.RegionInfo.CurrentRegion.IsMetric Then
            ' Use the Metric system
            Speed.Text = e.Speed.ToKilometersPerHour.ToString
        Else
            ' Use the Imperial system
            Speed.Text = e.Speed.ToStatuteMilesPerHour.ToString
        End If
    End Sub

    ' Updates the current altitude
    Private Sub UpdateAltitude(ByVal sender As Object, ByVal e As DistanceEventArgs)
        ' Are we using the Imperial or Metric system?
        If System.Globalization.RegionInfo.CurrentRegion.IsMetric Then
            ' Use the metric system
            Altitude.Text = e.Distance.ToMeters.ToString
        Else
            ' Use the Imperial system
            Altitude.Text = e.Distance.ToFeet.ToString
        End If
    End Sub

    ' Updates the current bearing
    Private Sub UpdateBearing(ByVal sender As Object, ByVal e As AzimuthEventArgs)
        ' Update the bearing
        Bearing.Text = e.Azimuth.ToString
        ' And show the current bearing represented as a cardinal (compass) direction
        Direction.Text = e.Azimuth.CardinalDirection.ToString
    End Sub

    ' Updates the currentposition (in UTM)
    Private Sub UpdateUtmPosition(ByVal sender As Object, ByVal e As UtmPositionEventArgs)
        ' Update the current position (in UTM)
        UtmPosition.Text = e.UtmPosition.ToString
    End Sub

    ' Updates the current location
    Private Sub UpdatePosition(ByVal sender As Object, ByVal e As PositionEventArgs)
        ' Update the current latitude
        Latitude.Text = e.Position.Latitude.ToString
        ' Update the longitude
        Longitude.Text = e.Position.Longitude.ToString
    End Sub

    ' Updates the current magnetic variation
    Private Sub UpdateMagneticVariation(ByVal sender As Object, ByVal e As LongitudeEventArgs)
        MagneticVariation.Text = e.Longitude.ToString
    End Sub

    Private Sub GPS_AltitudeChanged(ByVal sender As Object, ByVal e As DistanceEventArgs) Handles GpsReceiver.AltitudeChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Altitude has changed.")
        ' Update the current altitude
        Me.Invoke(New DistanceEventHandler(AddressOf UpdateAltitude), sender, e)
    End Sub

    Private Sub GPS_BearingChanged(ByVal sender As Object, ByVal e As AzimuthEventArgs) Handles GpsReceiver.BearingChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Bearing has changed.")
        ' Update the bearing and compass direction
        Me.Invoke(New AzimuthEventHandler(AddressOf UpdateBearing), sender, e)
    End Sub

    Private Sub GPS_SpeedChanged(ByVal sender As Object, ByVal e As SpeedEventArgs) Handles GpsReceiver.SpeedChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Speed has changed.")
        ' Update the speed
        Me.Invoke(New SpeedEventHandler(AddressOf UpdateSpeed), sender, e)
    End Sub

    Private Sub GPS_PositionChanged(ByVal sender As Object, ByVal e As PositionEventArgs) Handles GpsReceiver.PositionChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Position has changed.")
        ' Update the labels with the new position
        Me.Invoke(New PositionEventHandler(AddressOf UpdatePosition), sender, e)
    End Sub

    ' Raised when UTM coordinates have been reported from the GPS device
    Private Sub GPS_UtmPositionChanged(ByVal sender As Object, ByVal e As StormSource.Gps.UtmPositionEventArgs) Handles GpsReceiver.UtmPositionChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "UTM position has changed.")
        ' Update the UTM position
        Me.Invoke(New UtmPositionEventHandler(AddressOf UpdateUtmPosition), sender, e)
    End Sub

#End Region

#Region " Demonstration of Precision-Related Events "

    ' Updates the form with dilution of precision (accuracy) information
    Private Sub UpdateMeanDilutionOfPrecision(ByVal sender As Object, ByVal e As DilutionOfPrecisionEventArgs)
        ' Update the overall (mean) accuracy
        MeanDilutionOfPrecision.Text = e.DilutionOfPrecision.ToString
    End Sub

    ' Updates the form with dilution of precision (accuracy) information
    Private Sub UpdateHorizontalDilutionOfPrecision(ByVal sender As Object, ByVal e As DilutionOfPrecisionEventArgs)
        ' Update the accuract of latitude/longitude measurements
        HorizontalDilutionOfPrecision.Text = e.DilutionOfPrecision.ToString
    End Sub

    ' Updates the form with dilution of precision (accuracy) information
    Private Sub UpdateVerticalDilutionOfPrecision(ByVal sender As Object, ByVal e As DilutionOfPrecisionEventArgs)
        ' Update the accuracy of altitude measurements
        VerticalDilutionOfPrecision.Text = e.DilutionOfPrecision.ToString
    End Sub

    ' Raised when the accuracy of latitude/longitude measurements has changed
    Private Sub GPS_HorizontalDilutionOfPrecisionChanged(ByVal sender As Object, ByVal e As DilutionOfPrecisionEventArgs) Handles GpsReceiver.HorizontalDilutionOfPrecisionChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Lat/long accuracy has changed to " & e.DilutionOfPrecision.ToString)
        ' Update the accuracy information
        Invoke(New DilutionOfPrecisionEventHandler(AddressOf UpdateHorizontalDilutionOfPrecision), sender, e)
    End Sub

    ' Raised when the mean accuracy in the current latitude/longitude has changed
    Private Sub GPS_MeanDilutionOfPrecisionChanged(ByVal sender As Object, ByVal e As DilutionOfPrecisionEventArgs) Handles GpsReceiver.MeanDilutionOfPrecisionChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "General accuracy has changed to " & e.DilutionOfPrecision.ToString)
        ' Update the accuracy information
        Invoke(New DilutionOfPrecisionEventHandler(AddressOf UpdateMeanDilutionOfPrecision), sender, e)
    End Sub

    ' Raised when the confidence level of altitude measurements has changed
    Private Sub GPS_VerticalDilutionOfPrecisionChanged(ByVal sender As Object, ByVal e As DilutionOfPrecisionEventArgs) Handles GpsReceiver.VerticalDilutionOfPrecisionChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Altitude accuracy has changed to " & e.DilutionOfPrecision.ToString)
        ' Update the accuracy information
        Invoke(New DilutionOfPrecisionEventHandler(AddressOf UpdateVerticalDilutionOfPrecision), sender, e)
    End Sub

    Private Sub GPS_MagneticVariationChanged(ByVal sender As Object, ByVal e As LongitudeEventArgs) Handles GpsReceiver.MagneticVariationChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Magnetic variation has changed")
        ' Update the magnetic variation
        Invoke(New LongitudeEventHandler(AddressOf UpdateMagneticVariation), sender, e)
    End Sub

    Private Sub GPS_CrossTrackErrorChanged(ByVal sender As Object, ByVal e As StormSource.Gps.CrossTrackErrorEventArgs) Handles GpsReceiver.CrossTrackErrorChanged
        ' Update the cross-track error
        Me.Invoke(New CrossTrackErrorEventHandler(AddressOf UpdateCrossTrackError), sender, e)
    End Sub

#End Region

#Region " Demonstration of Exception Handling "

    Public Sub UpdateErrors(ByVal sender As Object, ByVal e As ErrorEventArgs)
        ' Add the error to the top of the list
        GpsExceptionTextBox.Text = e.Exception.ToString & vbCrLf & GpsExceptionTextBox.Text
    End Sub

    Public Sub UpdateParsingErrors(ByVal sender As Object, ByVal e As ParsingErrorEventArgs)
        ' Add the error to the top of the list
        ParsingExceptionTextBox.Text = e.ParsingException.ToString & vbCrLf & ParsingExceptionTextBox.Text
    End Sub

    ' NOTE: This event is raised for errors which occur on separate threads within the GpsReceiver.NET engine.
    '       Use Try..Catch blocks to handle typical GPS errors via the GPSException class.
    Private Sub GPS_ErrorOccurred(ByVal sender As Object, ByVal e As ErrorEventArgs) Handles GpsReceiver.ErrorOccurred
        Me.Invoke(New ErrorEventHandler(AddressOf UpdateErrors), sender, e)
    End Sub

    ' This event is raised when invalid or corrupt data is received by the device.  This event only
    ' serves as a warning that some data was not 100% understood.  These
    ' errors are not typically forwarded to the user.
    Private Sub GPS_ParsingErrorOccurred(ByVal sender As Object, ByVal e As ParsingErrorEventArgs) Handles GpsReceiver.ParsingErrorOccurred
        Me.Invoke(New ParsingErrorEventHandler(AddressOf UpdateParsingErrors), sender, e)
    End Sub
#End Region

#Region " Demonstration of Fix-Related Events "

    Public Sub UpdateFixInformation(ByVal sender As Object, ByVal e As System.EventArgs)
        If GpsReceiver.IsFixObtained Then
            FixObtained.Text = "Fix Obtained"
        Else
            FixObtained.Text = "No Fix Available"
        End If
        FixMethod.Text = GpsReceiver.FixMethod.ToString
        FixMode.Text = GpsReceiver.FixMode.ToString
        FixQuality.Text = GpsReceiver.FixQuality.ToString
        FixLikelihood.Text = GpsReceiver.FixLikelihood.ToString
    End Sub

    Private Sub GpsReceiver_FixLikelihoodChanged(ByVal sender As Object, ByVal e As StormSource.Gps.FixLikelihoodEventArgs) Handles GpsReceiver.FixLikelihoodChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Fix likelihood/stability has changed to " & e.FixLikelihood.ToString)
        ' Update the magnetic variation
        Invoke(New EventHandler(AddressOf UpdateFixInformation))
    End Sub

    Private Sub GPS_FixLost(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.FixLost
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Satellite fix has been lost.")
        ' Update the magnetic variation
        Invoke(New EventHandler(AddressOf UpdateFixInformation))
    End Sub

    Private Sub GPS_FixMethodChanged(ByVal sender As Object, ByVal e As FixMethodEventArgs) Handles GpsReceiver.FixMethodChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Satellite fix method has changed.")
        ' Update the magnetic variation
        Invoke(New EventHandler(AddressOf UpdateFixInformation))
    End Sub

    Private Sub GPS_FixModeChanged(ByVal sender As Object, ByVal e As FixModeEventArgs) Handles GpsReceiver.FixModeChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Satellite fix mode has changed.")
        ' Update the magnetic variation
        Invoke(New EventHandler(AddressOf UpdateFixInformation))
    End Sub

    Private Sub GPS_FixObtained(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.FixObtained
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Satellite fix has been obtained!")
        ' Update the magnetic variation
        Invoke(New EventHandler(AddressOf UpdateFixInformation))
    End Sub

    Private Sub GPS_FixQualityChanged(ByVal sender As Object, ByVal e As FixQualityEventArgs) Handles GpsReceiver.FixQualityChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "Satellite fix quality has changed")
        ' Update the magnetic variation
        Invoke(New EventHandler(AddressOf UpdateFixInformation))
    End Sub

#End Region

#Region " Demonstration of Satellite-Related GPS Events "

    Private Sub UpdateSatelliteCounts(ByVal sender As Object, ByVal e As SatelliteCountEventArgs)
        Select Case e.Type
            Case SatelliteCountType.ActiveCount
                ActiveSatellites.Text = e.Count
            Case SatelliteCountType.FixedCount
                FixedSatellites.Text = e.Count
            Case SatelliteCountType.TrackedCount
                TrackedSatellites.Text = e.Count
        End Select
    End Sub

    Private Sub UpdateSatellite(ByVal sender As Object, ByVal e As SatelliteEventArgs)
        With SatelliteList.Items(e.Satellite.Index)
            .Text = e.Satellite.PseudoRandomCode
            .SubItems(1).Text = e.Satellite.Elevation.ToString
            .SubItems(2).Text = e.Satellite.Azimuth.ToString
            .SubItems(3).Text = e.Satellite.SignalToNoiseRatio.ToString & " (" & e.Satellite.SignalToNoiseRatio.Rating.ToString & ")"
            If e.Satellite.IsFixObtained Then
                .BackColor = Color.FromArgb(60, 0, 255, 0)
            Else
                .BackColor = Color.FromArgb(60, 255, 0, 0)
            End If
        End With
    End Sub

    Private Sub GPS_SatelliteAzimuthChanged(ByVal sender As Object, ByVal e As SatelliteEventArgs) Handles GpsReceiver.SatelliteAzimuthChanged
        Invoke(New SatelliteEventHandler(AddressOf UpdateSatellite), sender, e)
    End Sub

    Private Sub GPS_SatelliteElevationChanged(ByVal sender As Object, ByVal e As SatelliteEventArgs) Handles GpsReceiver.SatelliteElevationChanged
        Invoke(New SatelliteEventHandler(AddressOf UpdateSatellite), sender, e)
    End Sub

    Private Sub GPS_SatelliteFixLost(ByVal sender As Object, ByVal e As SatelliteEventArgs) Handles GpsReceiver.SatelliteFixLost
        Invoke(New SatelliteEventHandler(AddressOf UpdateSatellite), sender, e)
    End Sub

    Private Sub GPS_SatelliteFixObtained(ByVal sender As Object, ByVal e As SatelliteEventArgs) Handles GpsReceiver.SatelliteFixObtained
        Invoke(New SatelliteEventHandler(AddressOf UpdateSatellite), sender, e)
    End Sub

    Private Sub GPS_SatellitePRCChanged(ByVal sender As Object, ByVal e As SatelliteEventArgs) Handles GpsReceiver.SatellitePseudoRandomCodeChanged
        Invoke(New SatelliteEventHandler(AddressOf UpdateSatellite), sender, e)
    End Sub

    Private Sub GPS_SatelliteSignalToNoiseRatioChanged(ByVal sender As Object, ByVal e As SatelliteEventArgs) Handles GpsReceiver.SatelliteSignalToNoiseRatioChanged
        Invoke(New SatelliteEventHandler(AddressOf UpdateSatellite), sender, e)
    End Sub

    ' Handles three events: SatelliteActiveCountChanged, SatelliteFixCountChanged, SatelliteTrackedCountChanged
    Private Sub GPS_SatelliteCountChanged(ByVal sender As Object, ByVal e As SatelliteCountEventArgs) Handles GpsReceiver.SatelliteFixedCountChanged, GpsReceiver.SatelliteActiveCountChanged, GpsReceiver.SatelliteTrackedCountChanged
        Invoke(New SatelliteCountEventHandler(AddressOf UpdateSatelliteCounts), sender, e)
    End Sub
#End Region

#Region " Demonstration of Raw Sentence Processing "

    ' Stores information about the current sentence
    Private CurrentSentence As String
    ' Returns True if the sentence was fully understood
    Private CurrentSentenceType As SentenceType

    ' Adds the specified sentence to the list
    Private Sub AddSentence(ByVal sender As Object, ByVal e As EventArgs)
        Select Case CurrentSentenceType
            Case SentenceType.Recognized
                ' The sentence was processed successfully
                RecognizedSentences.Items.Add(CurrentSentence)
                RecognizedSentences.SelectedIndex = RecognizedSentences.Items.Count - 1
                ' Prevent too many lines from being in the list box
                If RecognizedSentences.Items.Count > 50 Then RecognizedSentences.Items.RemoveAt(0)
            Case SentenceType.Unrecognized
                ' The sentence contained some corrupt data, or was proprietary to a specific device
                UnrecognizedSentences.Items.Add(CurrentSentence)
                UnrecognizedSentences.SelectedIndex = UnrecognizedSentences.Items.Count - 1
                ' Prevent too many lines from being in the list box
                If UnrecognizedSentences.Items.Count > 50 Then UnrecognizedSentences.Items.RemoveAt(0)
        End Select
    End Sub

    ' Handles two events: SentenceReceived and UnrecognizedSentenceReceived
    Private Sub GPS_SentenceReceived(ByVal sender As Object, ByVal e As SentenceEventArgs) Handles GpsReceiver.SentenceReceived, GpsReceiver.UnrecognizedSentenceReceived
        CurrentSentence = e.Sentence
        CurrentSentenceType = e.Type
        ' Now add the sentence
        Invoke(New EventHandler(AddressOf AddSentence))
    End Sub

    ' Raised when someone clicks on the "Parse" button.
    Private Sub ParseButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ParseButton.Click
        ' Parse the data which was entered into the text box
        Try
            GpsReceiver.Parse(ParsingText.Text)
        Catch ex As Exception
            Stop
        End Try
    End Sub
#End Region

#Region " Demonstration of GPS device date/time information "

    ' Updates the form with local date/time information
    Public Sub UpdateLocalTime(ByVal sender As Object, ByVal e As EventArgs)
        LocalTime.Text = Now.ToString
    End Sub

    ' Updates the form with GPS device's date/time information
    Public Sub UpdateGpsTime(ByVal sender As Object, ByVal e As DateTimeEventArgs)
        ' NOTE: GPS devices send time in UTC.  We must convert it to local time
        UTCDateTime.Text = e.DateTime.ToLocalTime.ToString
    End Sub

    ' Update the local time to show the comparison between local time and the time obtained from the GPS receiver
    Private Sub LocalTimeTimer_Elapsed(ByVal sender As System.Object, ByVal e As System.Timers.ElapsedEventArgs) Handles LocalTimeTimer.Elapsed
        Invoke(New EventHandler(AddressOf UpdateLocalTime))
    End Sub

    ' Raised whenever the GPS device reports a new date/time
    ' NOTE: Several devices stop sending this information as soon as a fix is obtained!
    Private Sub GPS_UTCDateTimeChanged(ByVal sender As Object, ByVal e As DateTimeEventArgs) Handles GpsReceiver.UtcDateTimeChanged
        Me.Invoke(New StatusBarEventHandler(AddressOf UpdateStatusBar), "GPS date/time has changed.")
        ' Update the magnetic variation
        Invoke(New DateTimeEventHandler(AddressOf UpdateGpsTime), sender, e)
    End Sub
#End Region

#Region " Demonstration of Waypoints "

    Private CurrentWaypoint As Waypoint

    ' Raised when the "Refresh" button is clicked on the Waypoints tab
    Private Sub DownloadWaypointButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DownloadWaypointButton.Click
        ' Retrieve the latest waypoints from the device (asynchronously)
        Try
            GpsReceiver.Waypoints.Refresh(True)
        Catch ex As GpsException
            MessageBox.Show(ex.ToString, "Unable to Load Waypoints", MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxDefaultButton.Button1)
        End Try
    End Sub

    ' Raised when a new waypoint is selected
    Private Sub WaypointList_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles WaypointList.SelectedIndexChanged
        ' Enable the Edit button
        EditWaypointButton.Enabled = True
    End Sub

    ' Raised when the "New..." button is clicked on the Waypoints tab
    Private Sub NewWaypointButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NewWaypointButton.Click
        ' Make a new waypoint form
        Dim WaypointForm As New NewWaypointForm
        ' Tell the form what kind of GPS device we're using
        WaypointForm.Device = GpsReceiver.Device
        ' Show the form
        WaypointForm.Show()
    End Sub

    ' Raised when the "Edit..." button is clicked on the Waypoints tab
    Private Sub EditWaypointButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles EditWaypointButton.Click
        ' Get the waypoint that was clicked
        Dim SelectedWaypoint As Waypoint = GpsReceiver.Waypoints(WaypointList.SelectedItems(0).Text)
        ' Make a new editor form
        Dim EditForm As New EditWaypointForm
        ' Tell this form to edit the selected waypoint
        EditForm.Waypoint = SelectedWaypoint
        ' Show the form
        EditForm.Show()
    End Sub

    ' Raised when a waypoint is double-clicked
    Private Sub WaypointList_DoubleClick(ByVal sender As Object, ByVal e As System.EventArgs) Handles WaypointList.DoubleClick
        ' Is anything selected?
        If WaypointList.SelectedItems.Count = 0 Then Exit Sub
        ' Open the selected item
        EditWaypointButton_Click(sender, e)
    End Sub

    Private Sub UpdateCrossTrackError(ByVal sender As Object, ByVal e As CrossTrackErrorEventArgs)
        ' Update the cross-track error
        Me.CrossTrackError.Text = e.CrossTrackError.ToString
        ' Update the recommended steering direction to correct the error
        Me.RecommendedSteeringDirection.Text = e.CrossTrackError.RecommendedSteeringDirection.ToString
    End Sub

    Private Sub UpdateOriginWaypoint(ByVal sender As Object, ByVal e As WaypointEventArgs)
        Me.OriginWaypoint.Text = e.Waypoint.ToString
    End Sub

    Private Sub UpdateDestinationWaypoint(ByVal sender As Object, ByVal e As WaypointEventArgs)
        Me.DestinationWaypoint.Text = e.Waypoint.ToString
    End Sub

    Private Sub UpdateClearWaypointList(ByVal sender As Object, ByVal e As EventArgs)
        DownloadWaypointButton.Enabled = False
        WaypointList.Items.Clear()
    End Sub

    Private Sub UpdateCompleteWaypointList(ByVal sender As Object, ByVal e As EventArgs)
        DownloadWaypointButton.Enabled = True
    End Sub

    ' Adds the specified sentence to the list
    Private Sub AddWaypoint(ByVal sender As Object, ByVal e As EventArgs)
        Dim WaypointListItem As ListViewItem
        ' Does this waypoint already exist in the list view?
        If WaypointItemExists(CurrentWaypoint.Name) Then
            ' Yes. Update the existing list view item
            WaypointListItem = GetWaypointItem(CurrentWaypoint.Name)
            WaypointListItem.SubItems(0).Text = CurrentWaypoint.Latitude.ToString
            WaypointListItem.SubItems(1).Text = CurrentWaypoint.Longitude.ToString
            WaypointListItem.SubItems(2).Text = CurrentWaypoint.Symbol.ToString
            WaypointListItem.SubItems(3).Text = CurrentWaypoint.Description
        Else
            ' No. Make a new list view item
            WaypointListItem = WaypointList.Items.Add(CurrentWaypoint.Name)
            WaypointListItem.SubItems.Add(CurrentWaypoint.Latitude.ToString)
            WaypointListItem.SubItems.Add(CurrentWaypoint.Longitude.ToString)
            WaypointListItem.SubItems.Add(CurrentWaypoint.Symbol.ToString)
            WaypointListItem.SubItems.Add(CurrentWaypoint.Description)
        End If
    End Sub

    ' Raised just before the collection of waypoints is re-downloaded
    Private Sub GPS_WaypointDownloadBegins(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.WaypointDownloadBegins
        Invoke(New EventHandler(AddressOf UpdateClearWaypointList))
    End Sub

    ' Returns True if the waypoint name currently exists in the WaypointList list view
    Private Function WaypointItemExists(ByVal name As String) As Boolean
        Dim WaypointListViewItem As ListViewItem
        For Each WaypointListViewItem In WaypointList.Items
            If WaypointListViewItem.Text = name Then Return True
        Next
    End Function

    ' Returns the waypoint list item associated with the specified waypoint name
    Private Function GetWaypointItem(ByVal name As String) As ListViewItem
        Dim WaypointListViewItem As ListViewItem
        For Each WaypointListViewItem In WaypointList.Items
            If WaypointListViewItem.Text = name Then Return WaypointListViewItem
        Next
        Return Nothing
    End Function

    ' Raised when one waypoint has been downloaded from the GPS device
    Private Sub GPS_WaypointDownloaded(ByVal sender As Object, ByVal e As StormSource.Gps.WaypointEventArgs) Handles GpsReceiver.WaypointDownloaded
        ' Set the current waypoint
        CurrentWaypoint = e.Waypoint
        ' And add it to the List View
        Invoke(New EventHandler(AddressOf AddWaypoint))
    End Sub

    ' Raised when the last waypoint has been downloaded from the device
    Private Sub GPS_WaypointDownloadEnds(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.WaypointDownloadEnds
        ' Re-enable the Refresh button
        Invoke(New EventHandler(AddressOf UpdateCompleteWaypointList))
    End Sub


    Private Sub GPS_DestinationWaypointArrivalAlarm(ByVal sender As Object, ByVal e As StormSource.Gps.WaypointEventArgs) Handles GpsReceiver.DestinationWaypointArrivalAlarm
        Stop
    End Sub

    Private Sub GPS_DestinationWaypointChanged(ByVal sender As Object, ByVal e As StormSource.Gps.WaypointEventArgs) Handles GpsReceiver.DestinationWaypointChanged
        ' Update the destination waypoint
        Me.Invoke(New WaypointEventHandler(AddressOf UpdateDestinationWaypoint))
    End Sub

    Private Sub GPS_OriginWaypointChanged(ByVal sender As Object, ByVal e As StormSource.Gps.WaypointEventArgs) Handles GpsReceiver.OriginWaypointChanged
        ' Update the origin waypoint
        Me.Invoke(New WaypointEventHandler(AddressOf UpdateOriginWaypoint))
    End Sub
#End Region

#Region " Demonstration of GPS Device Identification "

    ' Raised when GpsReceiver.NET is able to identify this device uniquely from any other device
    Private Sub GPS_DeviceIdentified(ByVal sender As Object, ByVal e As StormSource.Gps.DeviceEventArgs) Handles GpsReceiver.DeviceIdentified
        Invoke(New EventHandler(AddressOf UpdateDeviceInformation))
    End Sub

    Private Sub GPS_ProtocolChanged(ByVal sender As Object, ByVal e As StormSource.Gps.DeviceEventArgs) Handles GpsReceiver.ProtocolChanged
        Invoke(New EventHandler(AddressOf UpdateDeviceInformation))
    End Sub

    Private Sub GPS_ManufacturerChanged(ByVal sender As Object, ByVal e As StormSource.Gps.DeviceEventArgs) Handles GpsReceiver.ManufacturerChanged
        Invoke(New EventHandler(AddressOf UpdateDeviceInformation))
    End Sub

    Private Sub GPS_ProductNameChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles GpsReceiver.ProductNameChanged
        Invoke(New EventHandler(AddressOf UpdateDeviceInformation))
    End Sub

    Private Sub GPS_BatteryLifeChanged(ByVal sender As Object, ByVal e As StormSource.Gps.TimeSpanEventArgs) Handles GpsReceiver.BatteryLifeChanged
        Invoke(New EventHandler(AddressOf UpdateDeviceInformation))
    End Sub

    ' Updates the form on the form's thread
    Private Sub UpdateDeviceInformation(ByVal sender As Object, ByVal e As EventArgs)
        Try
            ' Update device indentification information
            Me.Manufacturer.Text = GpsReceiver.Device.Manufacturer.ToString
            Me.DeviceName.Text = GpsReceiver.Device.Name
            Me.SoftwareVersion.Text = GpsReceiver.Device.SoftwareVersion
            Me.Protocol.Text = GpsReceiver.Device.Protocol.ToString
            Me.BatteryLife.Text = GpsReceiver.Device.BatteryLife.ToString
            ' Update waypoint capabilities
            Me.WaypointAddressCheckbox.Checked = GpsReceiver.Device.SupportsWaypointAddress
            Me.WaypointAltitudeCheckbox.Checked = GpsReceiver.Device.SupportsWaypointAltitude
            Me.WaypointCityCheckbox.Checked = GpsReceiver.Device.SupportsWaypointCity
            Me.WaypointColorCheckbox.Checked = GpsReceiver.Device.SupportsWaypointColor
            Me.WaypointCommentCheckbox.Checked = GpsReceiver.Device.SupportsWaypointComment
            Me.WaypointCountryCheckbox.Checked = GpsReceiver.Device.SupportsWaypointCountry
            Me.WaypointIntersectingRoadCheckbox.Checked = GpsReceiver.Device.SupportsWaypointIntersectingRoad
            Me.WaypointDepthCheckbox.Checked = GpsReceiver.Device.SupportsWaypointDepth
            Me.WaypointDisplayModeCheckbox.Checked = GpsReceiver.Device.SupportsWaypointDisplayMode
            Me.WaypointFacilityNameCheckbox.Checked = GpsReceiver.Device.SupportsWaypointFacility
            Me.WaypointStateCheckbox.Checked = GpsReceiver.Device.SupportsWaypointState
            Me.WaypointSymbolCheckbox.Checked = GpsReceiver.Device.SupportsWaypointSymbol

            ' To make features stand out more, enable/disable the checkbox
            Me.WaypointAddressCheckbox.Enabled = Me.WaypointAddressCheckbox.Checked
            Me.WaypointAltitudeCheckbox.Enabled = Me.WaypointAltitudeCheckbox.Checked
            Me.WaypointCityCheckbox.Enabled = Me.WaypointCityCheckbox.Checked
            Me.WaypointColorCheckbox.Enabled = Me.WaypointColorCheckbox.Checked
            Me.WaypointColorComboBox.Enabled = Me.WaypointColorCheckbox.Checked
            Me.WaypointCommentCheckbox.Enabled = Me.WaypointCommentCheckbox.Checked
            Me.WaypointCountryCheckbox.Enabled = Me.WaypointCountryCheckbox.Checked
            Me.WaypointIntersectingRoadCheckbox.Enabled = Me.WaypointIntersectingRoadCheckbox.Checked
            Me.WaypointDepthCheckbox.Enabled = Me.WaypointDepthCheckbox.Checked
            Me.WaypointDisplayModeCheckbox.Enabled = Me.WaypointDisplayModeCheckbox.Checked
            Me.WaypointDisplayModeComboBox.Enabled = Me.WaypointDisplayModeCheckbox.Checked
            Me.WaypointFacilityNameCheckbox.Enabled = Me.WaypointFacilityNameCheckbox.Checked
            Me.WaypointStateCheckbox.Enabled = Me.WaypointStateCheckbox.Checked
            Me.WaypointSymbolCheckbox.Enabled = Me.WaypointSymbolCheckbox.Checked
            Me.WaypointSymbolComboBox.Enabled = Me.WaypointSymbolCheckbox.Checked
            ' Update available waypoint symbols
            WaypointSymbolComboBox.Items.Clear()
            WaypointSymbolComboBox.Items.AddRange(GpsReceiver.Device.GetSymbols)
            WaypointSymbolComboBox.SelectedIndex = 0
            ' Update available waypoint colors
            WaypointColorComboBox.Items.Clear()
            WaypointColorComboBox.Items.AddRange(GpsReceiver.Device.GetColors)
            WaypointColorComboBox.SelectedIndex = 0
            ' Update available waypoint display modes
            WaypointDisplayModeComboBox.Items.Clear()
            WaypointDisplayModeComboBox.Items.AddRange(GpsReceiver.Device.GetDisplayModes)
            WaypointDisplayModeComboBox.SelectedIndex = 0
            ' Enable/disable features based on the protocol
            Me.PowerOffButton.Enabled = (GpsReceiver.Device.Protocol = StormSource.Gps.Protocol.GarminBinary)
            Me.NewWaypointButton.Enabled = (GpsReceiver.Device.Protocol = StormSource.Gps.Protocol.GarminBinary)
            Me.DownloadWaypointButton.Enabled = (GpsReceiver.Device.Protocol = StormSource.Gps.Protocol.GarminBinary)
        Catch ex As Exception
        End Try
    End Sub

#End Region

#Region " Demonstration of powering off a GPS device "
    ' NOTE: Currently, the PowerOff() method is only supported when using the Garmin®
    '       binary protocol. Set your device to use the Garmin protocol before using this method.
    Private Sub PowerOffButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PowerOffButton.Click
        ' Confirm that the device should be powered off
        Select Case MessageBox.Show("When you turn off the GPS device, you will need to turn it back on manually.  Do you still want to power off the device?", "GPS Device Power-Off", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2)
            Case DialogResult.Yes
                Try
                    ' Try to power off the device.  If the device is not using the Garmin® protocol, this will fail
                    GpsReceiver.Device.PowerOff()
                Catch ex As GpsException
                    ' The power-off failed
                    MessageBox.Show("The device must be set to the Garmin® protocol in order for it to be shut off.  Please change the protocol and try again.", "Unable to Power Off", MessageBoxButtons.OK, MessageBoxIcon.Warning)
                End Try
        End Select
    End Sub
#End Region

#Region " Demonstration of Viewer Rotation "

    Private RotateThread As System.Threading.Thread

    Private Sub UpdateRotation()
        Do While True
            ' Increase the rotation angle by half a degree
            SatelliteViewer.Bearing += 0.4
            ' Sleep for 50ms
            System.Threading.Thread.Sleep(30)
        Loop
    End Sub

    Private Sub chkEnableRotation_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chkEnableRotation.CheckedChanged
        If chkEnableRotation.Checked Then
            ' Enable the rotation
            RotateThread = New System.Threading.Thread(New System.Threading.ThreadStart(AddressOf UpdateRotation))
            RotateThread.Name = "Demo of Rotating Satellite Viewer"
            RotateThread.IsBackground = True
            RotateThread.Start()
        Else
            ' Disable the rotation
            If Not RotateThread Is Nothing Then
                RotateThread.Abort()
                RotateThread = Nothing
            End If
            ' Reset the rotation to zero
            SatelliteViewer.Bearing = 0
        End If
    End Sub

#End Region

#Region " Demonstration of Viewer Customization "

    Private Sub chkShowPRCNumbers_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chkShowPRCNumbers.CheckedChanged
        SatelliteViewer.IsSatellitePrcVisible = chkShowPRCNumbers.Checked
    End Sub

    Private Sub ShowCompassCheckBox_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ShowCompassCheckBox.CheckedChanged
        SatelliteViewer.IsCompassVisible = ShowCompassCheckBox.Checked
    End Sub
#End Region

#Region " Miscellaneous Form Events "

    Public Delegate Sub StatusBarEventHandler(ByVal message As String)

    ' Used to update the status bar
    Public Sub UpdateStatusBar(ByVal message As String)
        StatusBar.Text = message
    End Sub

    Private Sub MainForm_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        ' Stop GPS services
        GpsReceiver.Stop()
        ' Clean up by disposing of resources
        LocalTimeTimer.Dispose()
        GpsReceiver.Dispose()
    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ' Bind the SatelliteViewer to our GPS receiver
        SatelliteViewer.Receiver = GpsReceiver
        ' Start updating the local time
        LocalTimeTimer.Enabled = True
    End Sub
#End Region

End Class