Read String From Serial port Visual Basic - vb.net

Question

Imports System.IO.Ports
Imports System.Text
Public Class Form4
Dim myStringBuilder As String
Dim insert As New OleDb.OleDbCommand
Dim cnn As New OleDb.OleDbConnection
Public user As String
Private Sub Serialport2_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort2.DataReceived
myStringBuilder = SerialPort2.ReadExisting()
Me.Invoke(New EventHandler(AddressOf UpdateControls))
End Sub
Private Sub UpdateControls(ByVal sender As Object, ByVal e As EventArgs)
Dim A As String = myStringBuilder
Dim Sqql As String
If Not cnn.State = ConnectionState.Open Then
cnn.Open()
End If
insert.Connection = cnn
Dim dt As New DataTable
Sqql = "SELECT * FROM `FileInfo` WHERE `File ID`='" & A & "'"
Dim cmd As New OleDb.OleDbDataAdapter(Sqql, cnn)
cmd.Fill(dt)
Dim i As Integer = dt.Rows.Count
Dim todaysdate As String = String.Format("{0:dd/MM/yyyy}", DateTime.Now)
If i = 1 Then
insert.CommandText = "INSERT INTO `File Log`(File ID,Name,Information,Time,Date) " & _
" VALUES('" & A & "','" & dt.Rows(0).Item("Name") & "','" & user & " telah" & dt.Rows(0).Item("Status") & "File" & "','" &
_
TimeOfDay & "','" & todaysdate & "')"
textBox1.Text += dt.Rows(0).Item("Name") & " " & TimeOfDay & " " & todaysdate &
Environment.NewLine
textBox1.Select(textBox1.TextLength, 0)
textBox1.ScrollToCaret()
insert.ExecuteNonQuery()
myStringBuilder = ""
Else
myStringBuilder = ""
textBox1.Text += A & Environment.NewLine
End If
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
cnn = New OleDb.OleDbConnection
cnn.ConnectionString = "Provider=Microsoft.Jet.Oledb.4.0; Data Source=" & Application.StartupPath & "\data.mdb"
If SerialPort2 IsNot Nothing Then
SerialPort2.Close()
End If
SerialPort2 = My.Computer.Ports.OpenSerialPort("COM27", 9600, Parity.None, 8, StopBits.One)
textBox1.Text = "-- Door Have Open -- " & Environment.NewLine & Environment.NewLine
End Sub
Private Sub textBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles textBox1.TextChanged
End Sub End Class
in my serial monitor view it will appear correctly but in visual basic it will auto break line and not display the string in one line.
I Tried other method like serialport.readline() but nothing happen.

Answer 1

If you are having issues with extracting data from your serial port you could try this:
Sub SerialPort_DataReceived(sender As Object, e As SerialDataReceivedEventArgs)
Dim currentSP As SerialPort = Convert.ChangeType(sender, GetType(SerialPort))
Dim strBuilder As System.Text.StringBuilder = New System.Text.StringBuilder()
For index = 1 To currentSP.BytesToRead
strBuilder.Append(Convert.ChangeType(currentSP.ReadByte(), GetType(Char)))
Next
' Have a global string to allow the threads to have a shared resource
myString = strBuilder.ToString()
Me.Invoke(New EventHandler(AddressOf UpdateControls))
End Sub
It should work the same way as the SerialPort.ReadLine(), this approach also lets you manipulate the data however you want. Instead of working with a string you could always work the data like this:
Dim buffer As Byte() = New Byte(currentSP.BytesToRead) {}
buffer(index) = Convert.ChangeType(currentSP.ReadByte(), GetType(Byte))
So instead of appending the Char to the String you can add the Byte to the buffer

Answer 2

Dim str As String = MyCOMPort.ReadExisting()
If Me.InvokeRequired Then
Me.Invoke(New dlUpdateText(AddressOf updatetext), str)
Else
updatetext(str)
End If