RS232 serial port communication c# win7 .net framework 3.5 sp1

Question

HI im new in c# serial port. im writing a c# program running is winXP and win7 to keep received data from the serial port when the machine was sent data.

using System.IO;
using System.IO.Ports;
using System.Threading;


namespace RS232RVR
{
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        SettingRS232();
    }

    public void SettingRS232 ()
    {
        try
        {
            SerialPort mySerialPort = new SerialPort("COM6");

            mySerialPort.BaudRate = 9600;
            mySerialPort.Parity = Parity.None;
            mySerialPort.StopBits = StopBits.One;
            mySerialPort.DataBits = 8;
            mySerialPort.Handshake = Handshake.None; //send to hardware flow control.

            mySerialPort.DataReceived += new SerialDataReceivedEventHandler(DataReceviedHandler);

            mySerialPort.Open();


            richTextBox1.Text = "on";

            mySerialPort.Close();
        }
        catch (Exception ex)
        {
            richTextBox1.Text = ex.Message;    
        }

    }

    private void DataReceviedHandler(
                    object sender,
                    SerialDataReceivedEventArgs e)
    {
        SerialPort sp = (SerialPort)sender;
        string indata = sp.ReadExisting();
        richTextBox1.Text = indata;

    }

}

}

COM6 is active in my pc. but my problem was seem the datareceived event is not fire when it has data coming from the serial port. ( i had checked the sport by using some of the freeware application)

anyone can help?

thanks

.NET's serial port class leaves a lot to be desired. [The Win32 comm functions](http://msdn.microsoft.com/en-us/library/aa363194.aspx) work much much better. — Ben Voigt, Feb 24 '11 at 07:05

score 5 · Answer 1 · answered Feb 24 '11 at 07:54

5

        mySerialPort.Open();
        richTextBox1.Text = "on";
        mySerialPort.Close();

That's not going to work, you'll close the serial port a couple of microseconds after opening it. Yes, the DataReceived event handler is not likely to fire. Only close the port when shutting down your program.

        mySerialPort.Handshake = Handshake.None

That's a problem too, you'll need to control the handshake signals yourself now. The vast majority of serial port devices won't send anything until they see the machine powered up and ready to receive. Set the DtrEnabled and RtsEnabled properties to true.

answered Feb 24 '11 at 07:54

Hans Passant

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I echoo Hans' main point: you open your port and then immediately close it. How is your app going to receive anything on a closed port? – Rich Turner Feb 24 '11 at 08:11
thanks Hans, sharp one..is working after i comment the port close..thank you and very helpful. – DesMY Feb 24 '11 at 08:15

score 1 · Answer 2 · answered Feb 24 '11 at 06:45

1

Did you copy that code from your application? Is it perhaps just a case that the event handler name is misspelled? E.g. DataReceviedHandler should actually be spelt DataReceivedHandler.

answered Feb 24 '11 at 06:45

Drew Goodwin

173
3

thanks Drew, is my big mistake for that. but i had change base on your reply. but it still doesn't work. – DesMY Feb 24 '11 at 06:56
i also refer to this http://stackoverflow.com/questions/466474/how-do-i-use-datareceived-event-of-the-serialport-port-object-in-c – DesMY Feb 24 '11 at 06:58

score 1 · Answer 3 · edited Feb 24 '11 at 23:05

The problem was solved and i would like to share it. i had fine dunning as below:

namespace RS232RVR
{
    public partial class Form1 : Form
    {
        private delegate void SetTextDeleg(string data);

        public Form1()
        {
            InitializeComponent();
            SettingRS232();
        }

        public void SettingRS232 ()
        {
            try
            {
                SerialPort mySerialPort = new SerialPort("COM6");

                mySerialPort.BaudRate = 9600;
                mySerialPort.Parity = Parity.None;
                mySerialPort.StopBits = StopBits.One;
                mySerialPort.DataBits = 8;
                mySerialPort.Handshake = Handshake.None;
                mySerialPort.ReadTimeout = 2000;
                mySerialPort.WriteTimeout = 500;

                mySerialPort.DtrEnable = true;
                mySerialPort.RtsEnable = true;

                mySerialPort.Open();
                //mySerialPort.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandler);
                mySerialPort.DataReceived += DataReceivedHandler;

                textBox1.Text = "Serial Port is Ready.";

            }
            catch (Exception ex)
            {
                textBox1.Text = ex.Message;    
            }

        }

        public void DataReceivedHandler(object sender,SerialDataReceivedEventArgs e)
        {
            SerialPort sp = (SerialPort)sender;
            System.Threading.Thread.Sleep(500);
            string indata = sp.ReadExisting();
            this.BeginInvoke(new SetTextDeleg(DisplayToUI), new object[] { indata });
            //textBox1.Text += indata;

        }

        private void DisplayToUI(string displayData)
        {
            textBox1.Text += displayData.Trim();
           // textBox1.Text += displayData;

        }

    }
}

If anyone have comment on the code you are welcome, is my pleasure and wish to code it better.

RS232 serial port communication c# win7 .net framework 3.5 sp1

3 Answers3

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