Hello. I'm primarily a hardware engineer but I just recently started working with microcontrollers and I'm now working on my software coding. I programmed an Atmel chip to receive data from the RS232 port and send it back to the computer where it is received successfully by hyperterminal.
I am now trying to make a
VB.net application (using
VB Express 2008) that will send data to the RS232 port where the microcontroller will send it back and it can be viewed on hyperterminal.
Below is the code I've been working with. I basically have a button (Button2) that opens and closes the serial port, textbox 4 where I can write code to be sent, and button3 which sends the code to the RS232 port. It should display what is sent as well as what is received on listbox1.
Enclosed is the code I have:
Code:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If ((CheckBox1.Checked = True) And (CheckBox2.Checked = True)) Then
TextBox1.Text = "Both"
ElseIf (CheckBox1.Checked = True) Then
TextBox1.Text = "One"
ElseIf (CheckBox2.Checked = True) Then
TextBox1.Text = "Two"
Else
TextBox1.Text = "You suck"
TextBox2.Clear()
MsgBox("Learn to Read, Noob!", MsgBoxStyle.Critical, "YOU FAIL")
End If
End Sub
Private Sub CheckBox2_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox2.CheckedChanged
End Sub
Private Sub CheckBox1_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox1.CheckedChanged
End Sub
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
TextBox2.Text = "You should pick one . . ."
If (ComboBox1.SelectedItem = "Apple") Then
TextBox2.Text = "Apple!"
ElseIf (ComboBox1.SelectedItem = "Orange") Then
TextBox2.Text = "Orange!"
ElseIf (ComboBox1.SelectedItem = "Monkey") Then
TextBox2.Text = "Monkey!"
ElseIf (ComboBox1.SelectedItem = "Donkey") Then
TextBox2.Text = "Donkey!"
End If
End Sub
Private Sub Label1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label1.Click
End Sub
Private Sub Label2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label2.Click
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
If SerialPort1.IsOpen = False Then
SerialPort1.Open()
If SerialPort1.IsOpen() Then
CheckBox3.Checked = True
TextBox3.Text = "Port Open"
Else
CheckBox3.Checked = False
TextBox3.Text = "Error: Port Closed"
End If
ElseIf SerialPort1.IsOpen = True Then
SerialPort1.Close()
If SerialPort1.IsOpen() Then
CheckBox3.Checked = True
TextBox3.Text = "Error: Port Open"
Else
CheckBox3.Checked = False
TextBox3.Text = "Port Closed"
End If
End If
End Sub
Private Sub TextBox3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
End Sub
Private Sub SerialPort1_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
ListBox1.Items.Add("Received: " + SerialPort1.ReadLine())
End Sub
Private Sub CheckBox3_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CheckBox3.CheckedChanged
End Sub
Private Sub TextBox3_TextChanged_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox3.TextChanged
End Sub
Private Sub Button3_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
SerialPort1.WriteLine(TextBox4.Text)
ListBox1.Items.Add("Sent: " + TextBox4.Text)
End Sub
Private Sub TextBox4_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox4.TextChanged
End Sub
End Class
I apologize for having some additional code (I've just been playing with this, learning how everything works) so some of it is unrelated but I figured I'd post everything just in case.
The error I'm seeing is:
"Cross-thread operation not valid: Control 'ListBox1' accessed from a thread other than the thread it was created on."
Does anyone happen to know what this error entails or how I can fix it? Please let me know when you get the chance. Thanks in advance!