Ccalling receive data function on Vb - vb.net

Question

I have gone through the Link vb serial communication. They ar eusing below function for getting data. My question are as follows
How to call this below function on VB
My data from serial are CSV value how to separate and display in a text box
Updating the text box values?
Function ReceiveSerialData() As String
' Receive strings from a serial port.
Dim returnStr As String = ""
Dim com3 As IO.Ports.SerialPort = Nothing
Try
com3 = My.Computer.Ports.OpenSerialPort("COM3")
com3.ReadTimeout = 10000
Do
Dim Incoming As String = com3.ReadLine()
If Incoming Is Nothing Then
Exit Do
Else
returnStr &= Incoming & vbCrLf
End If
Loop
Catch ex As TimeoutException
returnStr = "Error: Serial Port read timed out."
Finally
If com3 IsNot Nothing Then com3.Close()
End Try
Return returnStr
End Function
MY compelte code aS BELOW
Imports System
Imports System.IO.Ports
Imports System.ComponentModel
Imports System.Threading
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms
Imports Microsoft.VisualBasic.FileIO
Imports System.IO
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim myPort As Array
myPort = IO.Ports.SerialPort.GetPortNames()
PortComboBox.Items.AddRange(CType(myPort, Object()))
BaudComboBox.Items.Add(9600)
BaudComboBox.Items.Add(19200)
BaudComboBox.Items.Add(38400)
BaudComboBox.Items.Add(57600)
BaudComboBox.Items.Add(115200)
ConnectButton.Enabled = True
DisconnectButton.Enabled = False
Timer1.Interval = 1000
Timer1.Start()
Receive.Text = ReceiveSerialData()
End Sub
Private Sub ConnectButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ConnectButton.Click
SerialPort1.PortName = PortComboBox.Text
SerialPort1.BaudRate = CInt(BaudComboBox.Text)
SerialPort1.Open()
Timer1.Start()
'lblMessage.Text = PortComboBox.Text & " Connected."
ConnectButton.Enabled = False
DisconnectButton.Enabled = True
End Sub
Private Sub DisconnectButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DisconnectButton.Click
SerialPort1.Close()
DisconnectButton.Enabled = False
ConnectButton.Enabled = True
End Sub
Function ReceiveSerialData() As String
' Receive strings from a serial port.
Dim returnStr As String = ""
Dim com3 As IO.Ports.SerialPort = Nothing
Try
com3 = My.Computer.Ports.OpenSerialPort("COM3")
com3.ReadTimeout = 10000
Do
Dim Incoming As String = com3.ReadLine()
If Incoming Is Nothing Then
Exit Do
Else
returnStr &= Incoming & vbCrLf
End If
Loop
Catch ex As TimeoutException
returnStr = "Error: Serial Port read timed out."
Finally
If com3 IsNot Nothing Then com3.Close()
End Try
Return returnStr
End Function
End Class

Answer 1

i am trying to create a short sample for you but you need to understand threading and serial working for this. follow the steps to create this sample
add new class module to your code with name mySerial and past following code in it (replace code)
Imports System.Threading
Imports System.IO.Ports
Imports System.ComponentModel
Public Class dataReceivedEventArgs
Inherits EventArgs
Private m_StringData As String
Public Sub New(strData As String)
Me.m_StringData = strData
End Sub
Public ReadOnly Property ReceivedData As String
Get
Return m_StringData
End Get
End Property
End Class
Public Class mySerial
Private ReadThread As Thread
Dim SPort As SerialPort
Private syncContext As SynchronizationContext
Public Event DataReceived(Sender As Object, ByVal e As dataReceivedEventArgs)
Public Sub New(ByVal COMMPORT As String, ByVal BaudRate As Integer)
Me.New(COMMPORT, BaudRate, Parity.None, 8, StopBits.One)
End Sub
Public Sub New(ByVal _COMMPORT As String, ByVal _BaudRate As Integer, ByVal _Parity As Parity, ByVal _DataBits As Integer, ByVal _StopBits As StopBits)
SPort = New SerialPort
With SPort
.PortName = _COMMPORT
.BaudRate = _BaudRate
.Parity = _Parity
.DataBits = _DataBits
.StopBits = _StopBits
.Handshake = Handshake.XOnXOff
.DtrEnable = True
.RtsEnable = True
.NewLine = vbCrLf
End With
Me.syncContext = AsyncOperationManager.SynchronizationContext
ReadThread = New Thread(AddressOf ReadPort)
End Sub
Public Sub OpenPort()
If Not SPort.IsOpen Then
SPort.Open()
SPort.DiscardNull = True
SPort.Encoding = System.Text.Encoding.ASCII
ReadThread.Start()
End If
End Sub
Public Sub ClosePort()
If SPort.IsOpen Then
SPort.Close()
End If
End Sub
Private Sub ReadPort()
Do While SPort.IsOpen
Dim ReceviceData As String = String.Empty
Do While SPort.BytesToRead <> 0 And SPort.IsOpen And ReceviceData.Length < 5000
Try
ReceviceData &= SPort.ReadExisting()
Thread.Sleep(100)
Catch ex As Exception
End Try
Loop
If ReceviceData <> String.Empty Then
'raise event and provide data
syncContext.Post(New SendOrPostCallback(AddressOf onDataReceived), ReceviceData)
End If
Thread.Sleep(500)
Loop
End Sub
Private Sub onDataReceived(ByVal ReceivedData As String)
RaiseEvent DataReceived(Me, New dataReceivedEventArgs(ReceivedData))
End Sub
End Class
this is class which will work as wrapper class for you, now to make it work add a form with name frmSerial and a textBox with name txtData and set multiline=true, scrollbars=both, now past following code in it
Public Class frmSerial
Dim WithEvents _Serial As mySerial
Private Sub frmSerial_FormClosed(sender As Object, e As FormClosedEventArgs) Handles Me.FormClosed
_Serial.ClosePort()
End Sub
Private Sub frmSerial_Shown(sender As Object, e As EventArgs) Handles Me.Shown
_Serial = New mySerial("COM1", 9600)
_Serial.OpenPort()
End Sub
Private Sub _Serial_DataReceived(Sender As Object, e As dataReceivedEventArgs) Handles _Serial.DataReceived
txtData.Text &= e.ReceivedData
txtData.SelectionStart = txtData.Text.Length
txtData.ScrollToCaret()
End Sub
End Class
hop this helps you and people like you