Here is a very simple VB prog I wrote to test a connection to an Arduino.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim i As Long
Dim s As String
If Not SerialPort1.IsOpen() Then
SerialPort1.Open()
End If
TextBox1.Text = ""
TextBox1.Refresh()
Do While i < 50
SerialPort1.Write("<hello>")
s = SerialPort1.ReadLine()
TextBox1.Text = TextBox1.Text + s + vbCrLf
TextBox1.Refresh()
i = i + 1
Loop
End Sub
Private Sub Form1_Disposed(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Disposed
If SerialPort1.IsOpen() Then
SerialPort1.Close()
End If
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
SerialPort1.PortName = "Com33"
SerialPort1.Open()
End Sub
End Class
Just have a button and testbox plus drag a Serialport object onto the form. You don't need code to set the serial parameteres, it's all in the parameters window.
Rob