how to isolate GPS data into pieces?

I have the GPS data received as:
$GPRMC,040302.663,A,3939.7,N,10506.6,W,0.27,358.86,200804,,*1A

I want to isolate the GPS sentence into individual piece so I can display it into a textbox in a form with the following:

GPSTime:
Latitude:
Longitude:
Velocity:
Heading:

First thing is I need to detect the incoming text $GPRMC, if the $GPRMC is valid then use the data,

Who can I do that? I try to use the select case but it does not work.

Can anybody help me out?

Here is my code:

VB Code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        AxMSComm1.PortOpen = True
        Button1.Text = "OPENED"
        
    End Sub
 
    
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim gpsdata As String
        Dim txtFilter As String
        gpsdata = AxMSComm1.Input
        TextBox1.Text = gpsdata
        txtFilter = Mid(gpsdata, 1, 6)
        Select Case (txtFilter)
            Case "$GPRMC"
                TextBox2.Text = Mid(gpsdata, 8, 6)  'GPS Time
                TextBox3.Text = Mid(gpsdata, 21, 4) 'Latitude
                TextBox4.Text = Mid(gpsdata, 30, 4) 'Longitude
                'first, I want to make sure the above 3 boxes 
                'get the right data.
 
                'More data (other 2 boxes)will be implement later on
                'textbox5 - later
                'textbox6 - later
 
        End Select
    End Sub
End Class

Isolating GPS data

Yes, you can follow c0ding conventions ... if you do not have, talk to wossy. He gibs gud c0d.

BTW - You've just opened pandora's box :D

what is coding convention?

its the way you builld your life architecture. Check the link posted by BushMobile or talk to wossy.

Just split() on commas and select case the first element.

Also, find a good source of info on NMEA sentences like the one you posted.

Quote:

---

Originally Posted by cxiong

what is coding convention?

---

I nearly choked on my drink. :lol:

$gprmc,040302.663,a,3939.7,n,10506.6,w,0.27,358.86,200804,,*1a

time is the 2nd field
lat is 4th and 5th
long is 6th and 7th
speed is 8th
heading (from true north) is 9th.

You need to validate the checksum too, otherwise your data will be unreliable. I can't be bothered goin into detail on that because this is the wrong forum.