SerialPort 101 for a beginner

SerialPort 101 for a beginner

• Ruud van der Werf

  Ok can you help me get this thing working by just filling in the missing code if there is.Here is my updated code with the open serialport
  
  Public Class Form1
  Dim StoreReceived As String
  
  
  Private Sub SerialPort1_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
  
  SerialPort1.Open()
  StoreReceived = SerialPort1.ReadChar
  
  
  
  
  End Sub
  
  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  
  MessageBox.Show(StoreReceived)
  
  End Sub
  
  
  End Class
  
  
  

• Jeffyoung1234

  StoreReceived should store whatever string value captured from the StoreReceived = SerialPort1.ReadExisting.
  Also do i need to open/close the connection or it's done when i use the readExisting command.
  Please explain
  Thanks
  
  
  

• Jan Byvaly

  yes you do need to open and close the connection when you want to access the serial port

  there may not be any data being recieved hence why you will get a blank message box or even the fact that you have not opened a connection and data will not be recieved

  
  
  

• raviparthan

  take a look at this:

  http://msdn2.microsoft.com/en-us/library/30swa673.aspx

  does this help

  Basically you create an instance of the serialport class, set its properties, then open the connection and "write()" data to it.

  To read the data recieved, you need to implement the DataRecieved event:

  http://msdn2.microsoft.com/en-us/library/ed55271k.aspx

  
  
  

• Rod at Work

  Yes! it did work. Thank you for being patient with me. At this point i am getting a string of numbers from the serial port, i am going to store all of them in an array. But the problem is that i don't know how many characters i will be receiving in that case how can i creat an array with unknown size
  Second when i open the serial port. How can i check if i am still receiving data
  Here is what i have so far..Thank you again.
  
  Public Class Form1
  Dim StoreReceived(5) As String
  Dim i As Integer
  
  Private Sub btn_OpenPort_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_OpenPort.Click
  
  SerialPort1.Open()
  If SerialPort1.IsOpen Then
  MessageBox.Show("Serial Port Is Open")
  End If
  
  End Sub
  
  Private Sub btn_ShowReceivedData_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_ShowReceivedData.Click
  For i = 0 To 5
  
  StoreReceived(i) = SerialPort1.ReadByte
  
  TextBox1.Text = StoreReceived(i)
  
  
  
  Next
  
  
  End Sub
  
  Private Sub btn_ClosePort_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_ClosePort.Click
  
  SerialPort1.Close()
  
  End Sub
  
  
  End Class
  
  
  

• Sledgehammer

  there are no shortcuts, things have been simplified! :)

  you have to write the code, you maybe able to set properties from the Windows Designer however to read/write to the ports you have to write code otherwise how is it going to open/close/read/write to ports This is what a software developer does ;-)

  
  
  

• Carl Daniel

  Well you can use an arraylist and just "add" the data read, so globally you would have:

  Dim theDataItemsRecieved as new ArrayList()

  then in your DataRecieved event, just "add" the data recieved:

  Me.theDataItemsRecieved.Add(SerialPort1.ReadExisting())

  you dont need to "check" if you are recieving data, the DataRecieved event will automatically get fired/executed when there is data to be read from the port.

  
  
  

• tasleemarif

  what you have done so far is correct

  now to implement the dataRecieved event handler you can do this programmatically or via the Form designer so:

  click on the SerialPort object/control you have added on the form, then look at the properties Window. Click on the lightning icon, which indicates Events and double click on "DataRecieved".

  This will not create the DataRecieved event in your application for the serial port

   

  To write to the serial port, just enter:

  theSerialPort.Write("hi")

   

  or whatever, the serial port class has the Write() method which you can use to send data

   

  to read from the serial port, the DataRecieved event will be fired when there is data being recieved automatically.

   

   

  does this help

   

   

   

  
  
  

• Asim Zeeshan

  **can you help me figure this out.I am just following what you said.
  From the beginning. I openned a form in Vb Express and then I dragged the serialPort icon from the toolbox to the form and i defined all it's properties like baud rate, the com port and all that.
  
  next i created a button icon on the form and them i double clicked it so that i would get into the form1.vb[design] ( the code view window)
  The following code are generated:**
  
  
  Public Class Form1
  
  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
  
  
  End Sub
  End Class
  
  
  **at this point i need to open the port to read and write**
  ** The tutorial That you sent me mentions that i need to declare the **data received event handler.
  ** i am not sure about the code below,where should i included it in my **form1 code and how should i read/write from to the port
  

  Public Event DataReceived As SerialDataReceivedEventHandler
  
  Dim instance As SerialPort
  Dim handler As SerialDataReceivedEventHandler
  
  AddHandler instance.DataReceived, handle
  
  
  Thank you much
  
  

  
  
  
  
  

• Matthew Langley

  you are getting a blank message box because the variable "StoreRecieved" has nothing there.
  
  

• Ben-TSK

  Hello, Here is what i have at this point. I am just trying to read from the serial port . Am i missing anything all i get is a blank messagebox. Public Class Form1 Dim StoreReceived As String Private Sub SerialPort1_DataReceived(ByVal sender As System.Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived StoreReceived = SerialPort1.ReadExisting End Sub Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click MessageBox.Show(StoreReceived) End Sub End Class

  
  
  

• nate-d-o-double-g

  So from what i understand is that you created an instance of class arraylist() and you called it
  the dataItemsReceived .
  3 questions:
  
  Now when you say Me.theDataItemsRecieved.Add(SerialPort1.ReadExisting()) you are essentially storing whatever is read from the serial port into the dataItemsReceived object
  
  Also don't you need a loop to for the Me.theDataItemsRecieved.Add(SerialPort1.ReadExisting()) to store all the serial port stream
  
  and last question how can you display the content of the theDataItemsRecieved array i got an error when i used the for loop to do that since theDataItemsRecieved is an object and it's missing the dot operator
  
  
  

• Joel Martinez

  Thanks but i have looked all that up. Can i drag the serialport1 icon from the toolbox and then set it's property in the property window without writing that in code .
  I still need to open the port and read/write from it. I am looking here for shortcuts.
  Thanks
  
  
  

• Gurpreet Singh Gill

  thats incorrect.

  place a button on the form. Name it "open connection"

  double click this button

  type:

  SerialPort1.Open()

  on the form, place another button, name this "close connection"

  double click this button

  type:

  SerialPort1.Close()

  in your dataRecieved event handler, type:

  MessageBox.Show(StoreRecieved)

  
  
  
• SerialPort 101 for a beginner