C#

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    if (serialPort1.IsOpen) serialPort1.Close();
}

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{

    if(!serialPort1.IsOpen) return;

    char[] buff = new char[1];

    buff[0] = e.KeyChar;

    serialPort1.Write(buff, 0, 1);

    e.Handled = true;
}

private void DisplayText(object sender, EventArgs e)
{
    textBox1.AppendText(RxString);

}

private void serialPort1_DataReceived
  (object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
    RxString = serialPort1.ReadExisting();
    this.Invoke(new EventHandler(DisplayText));
}

SerialPort port=new SerialPort();
// take care of opening and port settings
...
// do whatever is needed to have the peripheral send something
...
// wait for enough data to arrive
Thread.Sleep(5000);
// read all of it now
int DIM=300;
byte[] bytes=new byte[DIM];
int n=port.Read(bytes,0,DIM);
for(int i=0; i<n; i++) {
    byte b=bytes[i];
    char c=b;
    log("bytes["+i+"]=0x"+b.ToString("X2")+"="+c);
}

public static void log(string s) {
    Console.WriteLine(s);
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO.Ports;


namespace SimpleSerial
{
    public partial class Form1 : Form
    {
        // Add this variable

        string RxString;

        public Form1()
        {
            InitializeComponent();
            string[] theSerialPortNames = System.IO.Ports.SerialPort.GetPortNames();
            /*MessageBox.Show(theSerialPortNames[0]);
            MessageBox.Show(theSerialPortNames[1]);
            MessageBox.Show(theSerialPortNames[2]);
            MessageBox.Show(theSerialPortNames[3]);*/
            //MessageBox.Show(theSerialPortNames[4]);
            //MessageBox.Show(theSerialPortNames[5]);
        }


        private void buttonStart_Click(object sender, EventArgs e)
        {
            serialPort1.PortName = "COM7";
            serialPort1.BaudRate = 115200;

            serialPort1.Handshake = Handshake.None;



            serialPort1.Open();
            if (serialPort1.IsOpen)
            {
                buttonStart.Enabled = false;
                buttonStop.Enabled = true;
                textBox1.ReadOnly = false;
            }
        }

        private void buttonStop_Click(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                serialPort1.Close();
                buttonStart.Enabled = true;
                buttonStop.Enabled = false;
                textBox1.ReadOnly = true;
            }

        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (serialPort1.IsOpen) serialPort1.Close();
        }

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
            // If the port is closed, don't try to send a character.

            if(!serialPort1.IsOpen) return;

            // If the port is Open, declare a char[] array with one element.
            char[] buff = new char[1];

            // Load element 0 with the key character.

            buff[0] = e.KeyChar;

            // Send the one character buffer.
            serialPort1.Write(buff, 0, 1);

            // Set the KeyPress event as handled so the character won't
            // display locally. If you want it to display, omit the next line.
            e.Handled = true;
        }

        private void DisplayText(object sender, EventArgs e)
        {
            textBox1.AppendText(RxString);

        }

        private void serialPort1_DataReceived
          (object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {
            RxString = serialPort1.ReadExisting();
            //RxString = serialPort1.ReadLine();
            serialPort1.Parity = Parity.None;
            serialPort1.StopBits = StopBits.One;
            serialPort1.DataBits = 8;
            serialPort1.NewLine = "(13)";
            this.Invoke(new EventHandler(DisplayText));
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void comboBox1_Click(object sender, EventArgs e)
        {

        }
    }
}

turbosupramk3 wrote:

serialPort1.NewLine = "(13)";

private void serialPort1_DataReceived_1(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{    
    txtToDisplay = serialPort1.ReadExisting();
    DisplayText();
}
        
public void DisplayText()
{
    if (txtIn.InvokeRequired)
    {
       this.BeginInvoke(new MethodInvoker(DisplayText));
    }
    else
    {
        txtIn.AppendText(txtToDisplay);
    }
}

private void GetComPorts() //populate the comm port list with the available system ports
{
    foreach (string s in SerialPort.GetPortNames() )
    {
        lbPort.Items.Add(s);
    }
}

private void btnOpen_Click(object sender, EventArgs e)
{

     this.lbPort.SelectedIndex = this.lbPort.TopIndex;          // which port?
     this.lbRate.SelectedIndex = this.lbRate.TopIndex;          // baud rate?
     this.lbProtocol.SelectedIndex = this.lbProtocol.TopIndex;  // N,8,1 or N,7,1 (strings in a collection)

     string crlf = Environment.NewLine;                         // this might be the real trick...

     serialPort1.BaudRate = Int32.Parse(lbRate.Text);
     serialPort1.PortName = lbPort.Text;

     serialPort1.Open();

     if (serialPort1.IsOpen)
     {
        btnOpen.Enabled = false;
        btnClose.Enabled = true;

        txtIn.AppendText(string.Format("Port {0} opened successfully." + crlf, serialPort1.PortName));
                
     }
}