[RESOLVED] SerialPort problem

[jasonli]

I am using SerialPort class to communicate with scale on COM1.

The communication is good tested by a serial port debug tool. I set COM1, 9600, N, 8, 1 and send "W"+NewLine, get received data like "0A 20 30 30 39 2E 37 35 4C 0D 0A 30 30 0D 03 0A 3F 0D 0A 3F 0D".

If I use SerialPort class to send and recieve, I only get "0A 3F 0D"., can't get the whole data.

Anybody have an idea about this?

As below is the part of source code:

        public SerialPort sPort;
        private void Form1_Load(object sender, EventArgs e)
        {
            sPort = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
            sPort.Handshake = Handshake.RequestToSend;
            sPort.Encoding = Encoding.ASCII;
            sPort.DataReceived += new SerialDataReceivedEventHandler(sPort_DataReceived);
            sPort.Open();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (!sPort.IsOpen)
                sPort.Open();

            sPort.WriteLine("W");
        }
        void sPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            try
            {
                byte[] buf = new byte[sPort.BytesToRead];
                sPort.Read(buf, 0, sPort.BytesToRead);
                string strs = "";
                foreach (byte ch in buf)
                {
                    strs += Convert.ToInt32(((int)ch)).ToString() + ",";
                }
                MessageBox.Show(strs);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

[eclipsed4utoo]

if you breakpoint, what is the value of "BytesToRead"?

[ricky_cpp]

Hello Jasonli,

I will suggest you to use asynchronous stream attached with base stream of your port. I was also useing port.Read but it was always gving me problems.

with stream assignment, you can use BeginRead and EndRead and it is really effective.

-Ricky

[jasonli]

Thank you guys for your help. I figured it out myself. It was because I send and receive data with type of text, not hex. I changed to hex and get all I want. There is no such setting for serial port, just convert text to hex and then send out, will receive hex data and convert to text.

Thank you guys again.