Creating a Serial Port in code in VB.net

Hi,

I am trying to create a serial port in VB.net using code only. Because I am creating a class library I cannot use the built-in component. I have tried instantiating a new SeialPort() object, but that does not seem to be enough. I'm sure there is something simple I am missing and any help would be greatly appreciated! Thanks!

P.S. I should add that the problem I am having at this time is getting the code to handle the datareceived event. Other than that it might be working, but I can't tell because of that problem.

From stackoverflow

• I have used the SerialPort .Net class in a past project and I worked fine. You really don't need anything else. Check the hardware setting in the control panel and make sure you instantiate the class with the same parameters.

• I found this article to be quite good.

  The code i wrote from it is:

  port = new System.IO.Ports.SerialPort(name, 4800, System.IO.Ports.Parity.None, 8, System.IO.Ports.StopBits.One);
  port.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(port_DataReceived);
  port.Open();
  
  void port_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
  {
      buffer = port.ReadLine();
      // process line
  }
  

  Sorry it's C# but...

  The only issue I have with it is if the port is dropped while it's open, the app seems to fail on exit.

• If you want to use the events make sure you declare your serialPort object using the 'withevents'. The below example will allow you to connect to a serial port, and will raise an event with the received string.

  Imports System.Threading
  
  Imports System.IO
  
  Imports System.Text
  
  Imports System.IO.Ports
  
  
  Public Class clsBarcodeScanner
  
  Public Event ScanDataRecieved(ByVal data As String)
  WithEvents comPort As SerialPort
  
  Public Sub Connect()
      Try
          comPort = My.Computer.Ports.OpenSerialPort("COM5", 9600)
      Catch
      End Try
  End Sub
  
  Public Sub Disconnect()
  
      If comPort IsNot Nothing AndAlso comPort.IsOpen Then
          comPort.Close()
      End If
  
  End Sub
  
  Private Sub comPort_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles comPort.DataReceived
      Dim str As String = ""
      If e.EventType = SerialData.Chars Then
          Do
              Dim bytecount As Integer = comPort.BytesToRead
  
              If bytecount = 0 Then
                  Exit Do
              End If
              Dim byteBuffer(bytecount) As Byte
  
  
              comPort.Read(byteBuffer, 0, bytecount)
              str = str & System.Text.Encoding.ASCII.GetString(byteBuffer, 0, 1)
  
          Loop
      End If
  
      RaiseEvent ScanDataRecieved(str)
  
  End Sub
  End Class
  

• Thank you all for your help, especially the answer about instantiating a class using the WithEvents keyword.

  I found a really great article that explains how to create a manager class for the serial port. It also discusses sending Binary as well as Hex data to the serial port. It was quite helpful.

  http://www.dreamincode.net/forums/showtopic37361.htm