.NET serial-ports - receiving missing data

Question

I'm working on a serialport application. And i'm not able to receive data properly. I'm using ReadExisting() for reading coming data.

and here is my code. Please advice, what is the proper way to receive data and what if i want to check the length of each message and the validity of format.

public void serialport_connect(String port, int baudrate, Parity parity, int databits, StopBits stopbits)
        {
            DateTime dt = DateTime.Now;
            String dtn = dt.ToShortTimeString();

            sport = new System.IO.Ports.SerialPort(port, baudrate, parity, databits, stopbits);

            try
            {
                sport.Open();
                status.AppendText("[" + dtn + "] " + "Connected\n");
                sport.DataReceived += new SerialDataReceivedEventHandler(sport_DataReceived);
            }
            catch (Exception ex) { MessageBox.Show(ex.ToString(), "Error"); }
        }

        private void sport_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            DateTime dt = DateTime.Now;
            String dtn = dt.ToShortTimeString();
            String comingData = sport.ReadExisting();

            if (comingData != String.Empty)
            {
                Dispatcher.Invoke(new Action(() =>
                {
                    current.AppendText("[" + dtn + "] " + "Received: " + sport.ReadExisting() + "\n");
                }));
            }

        }

Thank You.

Answer 1

Your event loop is much faster then the time required to send a single character at 9600 baud. I would recommend appending the received characters to a string until you receive a terminating char like "\n" or your receive the number of characters you expect.

Here is an example from a project where I wait until I receive 10 characters:

int datalen = serialPort1.BytesToRead;
label1.Text="Readexisting";
if (datalen >=10)
{
    string data = serialPort1.ReadExisting();
    label1.Text=data;
}