Delegate Sub SetTextCallback(ByVal ComeIn As String)
 
Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As _
  System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
        ReceivedText(SerialPort1.ReadExisting.Replace(vbLf, vbCrLf))
End Sub
 
    Public Sub ReceivedText(ByVal ComeIn As String)
        If TextBox1.InvokeRequired Then
            Dim x As New SetTextCallback(AddressOf ReceivedText)
            Me.Invoke(x, New Object() {ComeIn})
        Else
            TextBox1.Text = TextBox1.Text & ComeIn
            TextBox1.SelectionStart = TextBox1.TextLength
            TextBox1.ScrollToCaret()
 
            If TextBox1.Lines.Length > 0 Then
                Call Auswertung(TextBox1.Lines(TextBox1.Lines.Length - 1))
            End If
        End If
    End Sub
 
 
    Private Sub Auswertung(ByVal Wert As String)
          Auswertesachen....... 
    End Sub