' Gambas class file

' Description:

' CGPS.class

' u-blox AG MS1E GPS module (NMEA) support to get GPS time, precise position, and altitude

' GPS module version: $Version 1.3.4P00283 uBlx308

' Development Status:

' Reads serial data, needs parsing to be implemented.

' Wrote it for fun, no serious purpose for a non mobile server.

' Links:

' http://aprs.gids.nl/nmea/

' DomotiGa - an open source home automation program.

' Copyright(C) 2008-2009 Ron Klinkien

' Module additions Copyright(C) 2009 by Timo Sariwating

' Read file called COPYING for license details.

' Notes:

' NMEA sentences: 

' $GPBOD - Bearing, origin TO destination

' $GPBWC - Bearing AND distance TO waypoint, great circle

' $GPGGA - Global Positioning System Fix Data

' $GPGLL - Geographic position, latitude / longitude

' $GPGSA - GPS DOP AND active satellites

' $GPGSV - GPS Satellites IN view

' $GPHDT - Heading, TRUE

' $GPR00 - List OF waypoints IN currently active route

' $GPRMA - Recommended minimum specific Loran - C data

' $GPRMB - Recommended minimum navigation info

' $GPRMC - Recommended minimum specific GPS / Transit data

' $GPRTE - Routes

' $GPTRF - Transit Fix Data

' $GPSTN - Multiple Data ID

' $GPVBW - Dual Ground / Water Speed

' $GPVTG - Track made good AND ground speed

' $GPWPL - Waypoint location

' $GPXTE - Cross - track ERROR , Measured

' $GPZDA - Date & Time

PROPERTY Port AS String

PROPERTY Baud AS String

PROPERTY GPSDebug AS Boolean

PRIVATE sPort AS String

PRIVATE sBaud AS String

PRIVATE bGPSDebug AS Boolean

PUBLIC hGPS AS NEW SerialPort

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

' open serial port

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

PUBLIC FUNCTION Connect() AS Boolean

  ' try to close the port

  TRY hGPS.Close

  ' get a new one

  hGPS = NEW Serialport AS "GPS"

  WITH hGPS

    .PortName = sPort

    .Speed = sBaud

    .Parity = 0

    .DataBits = 8

    .StopBits = 1

    .FlowControl = 0

    .Open()

  END WITH

  ' all ok

  RETURN TRUE

CATCH ' some errors

  Main.WriteLog(("GPS Error: ") & ERROR.Text)

  RETURN FALSE

END

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

' close port

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

PUBLIC FUNCTION Disconnect() AS Boolean

  ' try to close the connection

  TRY hGPS.Close

  Main.WriteLog(("GPS serial port close."))

  ' all ok

  RETURN TRUE

CATCH ' some errors

  Main.WriteLog(("GPS Error: ") & ERROR.Text)

  RETURN FALSE

END

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

' got data input

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

PUBLIC SUB GPS_Read()

  DIM sData AS String

  LINE INPUT #hGPS, sData

  SELECT CASE Mid$(sdata, 2, 5)

    CASE "GPGLL" ' position

      Main.WriteDebugLog(("[GPS] Position: ") & sData)

    CASE "GPZDA" ' date & time

      Main.WriteDebugLog(("[GPS] Date & Time: ") & sData)

    CASE "GPGGA" ' fix data

      GPSFix(sData)

    CASE "GPGSV" ' satellites in view

    'Main.WriteDebugLog("[GPS] Satellites in view: " & sData)

  END SELECT

END

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

' parse fix data

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

PRIVATE FUNCTION GPSFix(sValue AS String)

  DIM sGPSFix AS String[]

  DIM sB, sC AS String

  DIM iCounter AS Integer = 1

  sGPSFix = Split(sValue, ",")

  FOR EACH sB IN sGPSFix

    SELECT CASE (iCounter)

      CASE 1

        INC iCounter

      CASE 2

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] Time: ") & sB)

        INC iCounter

      CASE 3

        sC = sB

        INC iCounter

      CASE 4

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] Latitude: ") & sC & " " & sB)

        sC = ""

        INC iCounter

      CASE 5

        sC = sB

        INC iCounter

      CASE 6

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] Longitude: ") & sC & " " & sB)

        sC = ""

        INC iCounter

      CASE 7

      IF bGPSDebug THEN

        SELECT CASE (sB)

        CASE 0

          Main.WriteDebugLog(("[GPS] Fix Quality: Invalid"))

          INC iCounter

        CASE 1

          Main.WriteDebugLog(("[GPS] Fix Quality: GPS Fix"))

          INC iCounter

        CASE 2

          Main.WriteDebugLog(("[GPS] Fix Quality: DGPS Fix"))

          INC iCounter

        END SELECT

        ELSE

          INC iCounter

        ENDIF

      CASE 8

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] Number of Satellites: ") & sB)

        INC iCounter

      CASE 9

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] HDOP: ") & sB)

        INC iCounter

      CASE 10

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] Altitude: ") & sB)

        INC iCounter

      CASE 11

        INC iCounter

      CASE 12

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] Heigh above WGS84: ") & sB)

        INC iCounter

      CASE 13

        INC iCounter

      CASE 14

        IF bGPSDebug THEN Main.WriteDebugLog(("[GPS] Time since last DGPS update: ") & sB)

        INC iCounter

      CASE 15

        IF bGPSDebug THEN

          Main.WriteDebugLog(("[GPS] DGPS Station ID: ") & Left$(sB, 4))

          Main.WriteDebugLog(("[GPS] CheckSum: ") & Right$(sB, -4))

        ENDIF

    END SELECT

  NEXT

END

' implement the properties

PRIVATE FUNCTION Port_Read() AS String

  RETURN sPort

END

PRIVATE SUB Port_Write(sValue AS String)

  sPort = sValue

END

PRIVATE FUNCTION Baud_Read() AS String

  RETURN sBaud

END

PRIVATE SUB Baud_Write(sValue AS String)

  sBaud = sValue

END

PRIVATE FUNCTION GPSDebug_Read() AS Boolean

  RETURN bGPSDebug

END

PRIVATE SUB GPSDebug_Write(sValue AS Boolean)

  bGPSDebug = sValue

END