Public Class Form1
    Dim WithEvents serialPort As New IO.Ports.SerialPort
   
'Combobox in cui vengono elencate in apertura di programma le porte COM disponibili
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        For i As Integer = 0 To My.Computer.Ports.SerialPortNames.Count - 1
            cbbCOMPorts.Items.Add(My.Computer.Ports.SerialPortNames(i))
        Next
        btnDisconnect.Enabled = False
    End Sub

'Bottone di connessione alla porta COM
    Private Sub btnConnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConnect.Click

        If serialPort.IsOpen Then
            serialPort.Close()
        End If

        Try
            With serialPort
                .PortName = cbbCOMPorts.Text
                .BaudRate = 9600
                .Parity = IO.Ports.Parity.None
                .DataBits = 8
                .StopBits = IO.Ports.StopBits.One
            End With
            serialPort.Open()

            lblMessage.Text = cbbCOMPorts.Text & " connected."
            btnConnect.Enabled = False
            btnDisconnect.Enabled = True
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
    End Sub

'Pulsante di disconnessione
    Private Sub btnDisconnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDisconnect.Click
        Try
            serialPort.Close()
            lblMessage.Text = serialPort.PortName & " disconnected."
            btnConnect.Enabled = True
            btnDisconnect.Enabled = False
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
    End Sub

'queste sono le sub che permettono la ricezione dei dati dal dispositivo
    Private Sub DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles serialPort.DataReceived

        txtDataReceived.Invoke(New myDelegate(AddressOf updateTextBox), New Object() {})
    End Sub

    Public Delegate Sub myDelegate()

    Public Sub updateTextBox()
        With txtDataReceived
            .Font = New Font("Arial", 12.0!, FontStyle.Bold)
            .SelectionColor = Color.Red
            .AppendText(serialPort.ReadExisting)
            .ScrollToCaret()
        End With
    End Sub

   
    Private Sub BbtnEsci_Click(sender As System.Object, e As System.EventArgs) Handles BbtnEsci.Click
        Me.Close()
    End Sub
End Class