Thread: VB6 serial port help

Hi Trevor,

are you converting the data properly? ie; if Bytearray is passed, you would either have to deal with it in bytes or convert it into String. If you upload your file, I can have a quick look.

Rana

Here is where I got the code to dismantle to get the info I want.

http://www.developerfusion.co.uk/show/5426/

I presume you've checked your code without using xport?

pulled from RR source

Code:

Public Sub ReadGPS()
Static Ltry As Double   'Last Time we tried to reconnect GPS
Static Buff As String   'Buffer of Data
Dim NB As Long          'Number of Bytes
Dim b() As Byte         'Array of Bytes
Dim DT() As String      'GPS Fields
Dim sData As String     'Temp GPS Data

    On Error Resume Next

    'Prevention -- Issue posted by Arathranar
    If Hibernated Then Exit Sub

    'If MM running
    If MMRunning Then
        Buff = frmMM.MM.Custom("GetNMEA|GGA", "D3Request") + vbCrLf
        Buff = Buff + frmMM.MM.Custom("GetNMEA|RMC", "D3Request") + vbCrLf
        GoTo ProcGPSData
    End If
    
    'If nothing to do
    If GPSPort = 0 Then Exit Sub
    
    'Try to read bytes
    NB = CommRead(GPSPort, b, 1024)
    
    'If Got Data
    If NB > 0 Then
        Buff = Buff + StrConv(b, vbUnicode)
ProcGPSData:
        NB = InStr(1, Buff, Chr(10), vbBinaryCompare)
        'while there are complete lines
        While NB > 0
            'Get Line of Data
            sData = Left(Buff, NB - 1)
            
            'Adjust Buffer
            Buff = Mid(Buff, NB + 1)
            
            'Process Line of Data
            If Left(sData, 1) = "$" Then
                DT = Split(sData, ",")
                Select Case DT(0)
                    Case "$GPRMC"
                        'Get Lat, Long, Speed and Heading
                        GPS.Lat = CDbl(Left(DT(3), InStr(1, DT(3), ".") - 1))
                        GPS.Lon = CDbl(Left(DT(5), InStr(1, DT(5), ".") - 1))
                        If CommaSys Then
                            'Prepare for Conversions
                            If CommaSys Then DT(3) = Replace(DT(3), ".", ",")
                            If CommaSys Then DT(5) = Replace(DT(5), ".", ",")
                            If CommaSys Then DT(7) = Replace(DT(7), ".", ",")
                            If CommaSys Then DT(8) = Replace(DT(8), ".", ",")
                            'Get Lat/Long
                            GPS.Lat = GPS.Lat \ 100# + (CDbl(Mid(DT(3), InStr(1, DT(3), ",") - 2)) / 60#)
                            GPS.Lon = GPS.Lon \ 100# + (CDbl(Mid(DT(5), InStr(1, DT(5), ",") + -2)) / 60#)
                        Else
                            GPS.Lat = GPS.Lat \ 100# + (CDbl(Mid(DT(3), InStr(1, DT(3), ".") - 2)) / 60#)
                            GPS.Lon = GPS.Lon \ 100# + (CDbl(Mid(DT(5), InStr(1, DT(5), ".") + -2)) / 60#)
                        End If
                        If DT(4) = "S" Then GPS.Lat = -GPS.Lat
                        If DT(6) = "W" Then GPS.Lon = -GPS.Lon
                        GPS.speed = CDbl(DT(7))
                        GPS.HDG = CInt(DT(8))
                    Case "$GPGGA"
                        'Get Altitude and Sat Count
                        If CommaSys Then DT(9) = Replace(DT(9), ".", ",")
                        GPS.Alt = CDbl(DT(9))
                        GPS.SATS = CInt(DT(7))
                        GPS.Valid = (Val(DT(6)) > 0)
                End Select
            End If
            
            'Check for more lines
            NB = InStr(1, Buff, Chr(10), vbBinaryCompare)
        Wend
        'Reset Timeout Timer
        Ltry = Timer
    Else
        'Didn't get any data in 10 seconds (Problem ?)
        'Try to reconnect GPS
        If Timer - Ltry > 10 And MMRunning = False And CurSCR <> "destinator_gps.skin" Then
            GPS.Valid = False
            'Close Port
            CommClose GPSPort
            'Give O.S. processing time
            Sleep 1
            'Try to Re-open it
            CommOpen GPSPort, "\\.\COM" + CStr(GPSPort), "baud=4800 parity=N data=8 stop=1"
            CommSetLine GPSPort, 2, True   'Data Terminal Ready ON (in case)
            Ltry = Timer
        End If
        If Ltry > Timer Then Ltry = Timer
    End If

End Sub

might be of some help :-)

CdR

Laidback, you're still about then?

hey, thanks for the replies.

This is the first time I've ever tried anything regarding the serial port, so what I came up with is not very fancy. It was stuff i found with google here and there, and kinda molded into something that i thought would work, so please bear with me.

I've attached my little test program which basically takes whatever is in the input buffer and using the split function splits it into words() using a comma as the delimiter. If words(0) = "$GPRMC" then it takes words(7) and converts it from knots to km/h and puts it in a textbox, and words(8) (bearing) in another box. I have the MsComm control set to Com10 as that's the com i set aside for it on xPort, it can be changed in the properties of the control. Clicking the start/stop button simply sets the mscomm1.portopen property to true or false.

I'm pretty sure it's not the right way to go about this, but it's very simple and i came up with it in about an hour. I don't know how else I can test my program, and I know very little about serial programming.

Thanks for the help

Originally Posted by Enforcer

Here is where I got the code to dismantle to get the info I want.

http://www.developerfusion.co.uk/show/5426/

The class file in the zip on the above page was really what I was looking for in the first place, but couldn't find anything. I'd still like to see if what I wrote is going to work with little modification, but if not I can just use the class file

Originally Posted by Enforcer

Laidback, you're still about then?

Of course, an enforced holiday from broadband, a stuffed mother board and a new house needing plenty of work but I still stick my nose in now & again. :-)

did you send your broadband a postcard