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POHow to recieve and read data through UART from microcontroller using VB
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  1. POHow to recieve and read data through UART from microcontroller using VB
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    copied!<p>I will be posting my code for whatever I have done till now. </p> <p>I'm sending data to microcontroller, but now I've to check other way and want to receive data. </p> <p>I have written code which itself acts as <code>UART</code>. I am using readexisting and able to read some characters which is unrelevent, but I'm not able to read required data.</p> <pre><code>Imports System.IO.Ports Public Class Settings Dim myComPort As New SerialPort ' Call a routine to write a command to turn on an LED and read the response. Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click SendCommand("7") End Sub ' Call a routint write a command to turn on an LED and read the response. Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click SendCommand("A") End Sub Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click SendCommand("C") End Sub Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click myComPort.BaudRate = CInt(cmbBitRate.SelectedItem) TextBox4.Text = myComPort.BaudRate End Sub ' If myComPort is open, finish transmitting. ' Exiting the Using block closes the port and releases its resources. Sub CloseComPort() Try Using myComPort If (Not (myComPort Is Nothing)) Then ' The COM port exists. If myComPort.IsOpen Then ' Wait for the transmit buffer to empty. Do While (myComPort.BytesToWrite &gt; 0) Loop End If End If End Using Catch ex As UnauthorizedAccessException ' The port may have been removed. Ignore. End Try End Sub ' Set the BaudRate property of myComPort to match the bit rate selected in the combo box. Private Sub ComboBox2_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmbBitRate.SelectedIndexChanged myComPort.BaudRate = CInt(cmbBitRate.SelectedItem) 'TextBox2.Text = ToString(myComPort.BaudRate) End Sub ' If the previously selected COM port is open, close it. ' Set the PortName property of myComPort to match the port selected in the combo box. ' Call a routine to open the port. Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmbPorts.SelectedIndexChanged CloseComPort() myComPort.BaudRate = CInt(cmbBitRate.SelectedItem) ' myComPort.BaudRate = 500 'TextBox2.Text = myComPort.BaudRate OpenComPort() End Sub ' Call a routine to close the COM port. Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing CloseComPort() End Sub ' Call routines to initalize the form and open the selected COM port. Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load InitializeForm() OpenComPort() AddHandler myComPort.DataReceived, AddressOf DataReceivedeventHandler End Sub ' Set up the form and select a default port and bit rate. Sub InitializeForm() Dim bitRates(9) As Integer Dim nameArray() As String ' Find the COM ports on the system. nameArray = SerialPort.GetPortNames Array.Sort(nameArray) ' Fill a combo box with the port names. cmbPorts.DataSource = nameArray cmbPorts.DropDownStyle = ComboBoxStyle.DropDownList ' Select a default port. 'cmbPorts.SelectedIndex = 1 'Bit rates to select from. bitRates(0) = 300 bitRates(1) = 600 bitRates(2) = 1200 bitRates(3) = 2400 bitRates(4) = 9600 bitRates(5) = 14400 bitRates(6) = 19200 bitRates(7) = 38400 bitRates(8) = 57600 bitRates(9) = 115200 'Place the bit rates in a combo box. cmbBitRate.DataSource = bitRates cmbBitRate.DropDownStyle = ComboBoxStyle.DropDownList ' Select a default bit rate. ' If (Not (cmbBitRate Is Nothing)) Then 'CloseComPort() 'End If End Sub ' Set port parameters and open the COM port ' associated with the SerialPort object myComPort. Sub OpenComPort() Try ' Get the selected COM port's name from the combo box. If Not myComPort.IsOpen Then myComPort.PortName = cmbPorts.SelectedItem.ToString ' Get the selected bit rate from the combo box. If cmbBitRate.SelectedIndex &gt; 0 Then myComPort.BaudRate = CInt(cmbBitRate.SelectedItem) TextBox4.Text = myComPort.BaudRate End If 'myComPort.BaudRate = CInt(cmbBitRate.SelectedItem) ' Set other port parameters. myComPort.Parity = Parity.None myComPort.DataBits = 8 myComPort.StopBits = StopBits.One myComPort.Handshake = Handshake.None myComPort.ReadTimeout = 3000 myComPort.WriteTimeout = 5000 ' Open the port. myComPort.Open() End If Catch ex As InvalidOperationException MessageBox.Show(ex.Message) Catch ex As UnauthorizedAccessException MessageBox.Show(ex.Message) Catch ex As System.IO.IOException MessageBox.Show(ex.Message) End Try End Sub ' Write a command to the SerialPort object and read the response. ''' &lt;param name= "command"&gt; The command to send. &lt;/param&gt; Private Sub SendCommand(ByVal command As String) ' Dim response As String Try 'TextBox1.BackColor = Color.MediumPurple myComPort.Write(command) 'myComPort.ReadTimeout = 1000 ' While myComPort.ReadLine = 0 ' End While 'If myComPort.IsOpen Then 'myComPort.ReadLine() 'End If 'TextBox6.Text = myComPort.ReadLine Select Case command Case "A" ' TextBox6.Text = myComPort. TextBox1.Text = "Green LED is on" TextBox1.BackColor = Color.LightGreen Case "7" TextBox1.Text = " Red LED is ON" TextBox1.BackColor = Color.Red 'TextBox6.Text = myComPort.ReadLine Case "C" TextBox1.Text = " Both LED's are ON" TextBox1.BackColor = Color.RoyalBlue 'TextBox6.Text = myComPort.ReadLine Case Else End Select Catch ex As TimeoutException MessageBox.Show(ex.Message) Catch ex As InvalidOperationException MessageBox.Show(ex.Message) Catch ex As UnauthorizedAccessException MessageBox.Show(ex.Message) End Try End Sub Public Sub DataReceivedeventHandler( ByVal sender As Object, ByVal e As SerialDataReceivedEventArgs) Dim sp As SerialPort = CType(sender, SerialPort) Dim indata As String = sp.ReadExisting() ' Dim jndata As String = sp.ReadChar MsgBox(indata) 'TextBox6.Text = CStr(vbMsgBoxRtlReading) ' MsgBox(jndata) ' Console.WriteLine("Data Received:") Console.Write(indata) ' ArgumentException.Equals(indata) End Sub Public Sub TextBox6_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox6.TextChanged End Sub 'Private Sub DataReceivedEventHandler(ByVal sender As Object, ByVal e As SerialDataReceivedEventArgs) ' Throw New NotImplementedException 'End Sub End Class </code></pre>
 

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