[2005] Reading a RS232 port

[jamesclarke112]

I haven't received the kit yet, but am doing some pre-lim research. I will soon have an RFID reader/writer which has a RS232 interface. I will need in my VB app to read the data of the card when it is swiped via the reader.

Anyone know of any tutorials etc... for using a serial interface in VB 2005?

Thanks for any help

[Pirate]

check codeproject.com

[sparrow1]

I haven't received the kit yet, but am doing some pre-lim research. I will soon have an RFID reader/writer which has a RS232 interface. I will need in my VB app to read the data of the card when it is swiped via the reader.

Anyone know of any tutorials etc... for using a serial interface in VB 2005?

Thanks for any help

Hi,

You could try this link;

http://search.msdn.microsoft.com/sea...siteid=0&tab=0

Wkr,

sparrow1

[Sunglasses Ron]

if you check this link there is a basic working example.

http://www.vbforums.com/showthread.php?t=402916

you can get a pretty good idea about how it all works & then check MSDN
for more detail. if you search "COM Port Sample" there is a project that you
can download. I have'nt tried it but MS samples are usually pretty good.

note that the Serialport.Readline method will read the input buffer until a
"Newline" is received. So it is necessary to find out what the terminating
characters are that will be sent by your connected equipment (usually
something like a carriage return). Then you can set the Newline property to
what is required. The default is CrLf (carrige return linefeed).


if you need to read the buffer one byte at a time you can use something like
this....

Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived 
 
           If SerialPort1.BytesToRead > 0 Then 
             Do
                  rxbyte.Add(SerialPort1.ReadByte)                    
                  TextBox1.Invoke(New myDelegate(AddressOf updateTextBox1), _ 
                  New Object() {}) 
                   Exit Do 
             Loop 
         End If 
 
       End Sub

hope this helps.

[jamesclarke112]

Thanks for the pointers. Am I right in assuming that if I connect a USB device it will create a virtual com port if it doesn't create a new drive (e.g. like a digital camera would), and then I could use the same methods described above to read in the data?

Thanks

[josep]

Yes,

You're right. But it's better if you test it with a real RS232 port, I experienced a lot of problems with USB to RS232 converters (to avoid headaches with correct code and non working hardware).

If you have no serial port on your laptop, you can use some PCMCIA to RS232 converters (QUATECH) had some god ones, that work without this problems.

[jamesclarke112]

The reason I asked about the USB is that I have been told that the reader is not RS232 but USB. I assume that the issue of converting is not a problem now and using the virtual com port is the only option?

[josep]

normally these devices includes dll on an SDK (probably not .net dll). That gives you all functionality for the device.

[jamesclarke112]

All I got was the reader with a USB connection. I believe I can get hold of a dll for c++, but I take it that would be of no use in .NET