reading data from a USB port using VB.net and Visual Studio Community - windows Forms application

Question

I need to read lines of data coming in on a USB port. I am using VB.net and Forms. In the toolbox, there is a 'SerialPort' control which I placed in my Form1.vb[Design] window. I am using the 'DataReceived' event and the event handler test code is:

Private Sub ttest(sender As Object, e As EventArgs) Handles SerialPort1.DataReceived
txtNext.Text = "x" ' simply writes an 'x' into a text box if the handler is called
End Sub

The event handler is never executed even though there is a constant arrival of lines of text on the serial port

Any suggestions?

Answer 1

Hi @Lloyd Linnell ,

Thank you for posting here.

Here's an example of using serial port to receive data, and you can refer to it.

    Private isOpened As Boolean = False  
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click  
        If Not isOpened Then  
            SerialPort1.PortName = "your port name"  
            SerialPort1.BaudRate = yourBaudRate  
  
            Try  
                ' Open the serial port.  
                SerialPort1.Open()  
                isOpened = True  
                AddHandler SerialPort1.DataReceived, AddressOf ttest_DataReceived  
            Catch  
                MessageBox.Show("Failed to open serial port!")  
            End Try  
        Else  
  
            Try  
                ' Close the serial port.  
                SerialPort1.Close()  
                isOpened = False  
            Catch  
                MessageBox.Show("Failed to close the serial port!")  
            End Try  
        End If  
    End Sub  
  
    Private Sub ttest_DataReceived(ByVal sender As Object, ByVal e As SerialDataReceivedEventArgs)  
        txtNext.Text = "x"  
    End Sub  

Hope it could be helpful.

Besides, if the code cannot help you find the solution, please provide some related code about your question.

Best Regards,
Xingyu Zhao
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