Zeilenumbruch via RS232

Hallo!!

Ich möchte übungshalber einen Kleinen String verschicken.

Damit es mein Arduino versteht, muss nach dem Text ein Zeilenumbruch sein.

Mein Code:

Imports System.IO.Ports.SerialPort

Public Class Form1

Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
If SerialPort1.IsOpen Then
SerialPort1.Write(ChrW(100))
End If
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

'Verfügbare Comports suchen
Dim ports As String() = GetPortNames()
Dim Port As String

'Combobox richtig sortieren
ComboBox_Comport.Items.Clear()

If ports.Length > 0 Then

' für alle COM-Nr. < 10 ein Leerzeichen einfügen
For ii As Integer = 0 To (ports.Length - 1)
If CInt(ports(ii).Substring(3)) < 10 Then
ports(ii) = "COM " & ports(ii).Substring(3)
End If
Next

Array.Sort(ports)

' das Leerzeichen in "COM x" wieder entfernen
For ii As Integer = 0 To (ports.Length - 1)
ports(ii) = "COM" & ports(ii).Substring(3).Trim
Next

End If

'In die Combobox übernehmen
For Each Port In ports
ComboBox_Comport.Items.Add(Port)
Next Port

'Buttons setzen
Button_Disconnect.Enabled = False
Button_Connect.Enabled = False
Button1.Enabled = False
Button3.Enabled = False

End Sub

Private Sub ComboBox_Comport_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox_Comport.SelectedIndexChanged

'Comport auswählen
If ComboBox_Comport.SelectedItem <> "" Then
Button_Connect.Enabled = True
End If

End Sub

Private Sub Button_Connect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Connect.Click

'Comport verbinden
Try

'Buttons freigeben-/ sperren
Button_Connect.Enabled = False
Button_Disconnect.Enabled = True
ComboBox_Comport.Enabled = False
Button1.Enabled = True
Button3.Enabled = True

'Comport Einstellungen
SerialPort1.PortName = ComboBox_Comport.Text
SerialPort1.BaudRate = 9600
SerialPort1.Open()

Timer1.Enabled = True

Catch ex As Exception

'Fehlermeldung
MessageBox.Show("Achtung die Schnittstelle konnte nicht geöffnet werden! " + e.ToString _
, "Ausnahmefehler", MessageBoxButtons.OK, MessageBoxIcon.Error)
Button_Connect.Enabled = True
Button_Disconnect.Enabled = False
ComboBox_Comport.Enabled = True

End Try

End Sub

Private Sub Button_Disconnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button_Disconnect.Click

'Verbindung trennen
SerialPort1.Write(ChrW(100))
Timer1.Enabled = False
Button_Connect.Enabled = True
Button_Disconnect.Enabled = False
ComboBox_Comport.Enabled = True
Button1.Enabled = False
Button3.Enabled = False
SerialPort1.Close()

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If SerialPort1.IsOpen Then
SerialPort1.Write("Ein")
SerialPort1.NewLine()
End If
End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
If SerialPort1.IsOpen Then
SerialPort1.Write("Aus")
SerialPort1.NewLine
End If
End Sub
End Class

Wie kann ich Statt dem " SerialPort1.NewLine()" einen Zeilenumbruch machen?

Danke für eure Hilfe!!