Question

我是这个论坛的新手，我在C＃编程方面没有太多经验。我用C＃构建了一个简单的Windows应用程序来与我朋友给我的一些电子板进行通信。他在38400的微控制器中定义了串口波特率。我想尽快通过串口发送和接收字节。使用C＃中的现有serialport工具，我只能读取字节，但即使在自己的线程中使用eventhandler，仍然不够快。我的缓冲区[4096]在几秒钟内就满了。

我的问题是，是否存在一些用于串行端口通信的其他功能或工具，这些功能或工具不会占用太多处理器时间。我需要读取少于200 us的一个字节。我对嵌入式系统有更多经验，这不是问题。

感谢大家提出一些建议或想法。

托马日

Answer 1

感谢所有回复。我可以读取来自电路板的所有字节，但我无法快速回复。这是我的代码。我使用了一个事件来读取缓冲区。如果我尝试在事件中回复，则下一个字节包含错误的值。

#region namespace usings
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using System.IO;
using System.IO.Ports;
using System.Threading;
using System.Runtime.InteropServices;
using System.Diagnostics;

using Microsoft.Win32;
using Zaber.Serial.Core;
using Diagnostics = System.Diagnostics;
#endregion

命名空间Lucifire_aplication {

public partial class Form1 : Form
{


    int k = 1;
    string number_of_bytes;
    byte checksum;
    byte[] buffer = new byte[11];
    byte[] buffer_old = new byte[11];


    public Form1()
    {
        InitializeComponent();
        configure_button.Enabled = false;
        start_button.Enabled = false;
        foreach (string s in SerialPort.GetPortNames())
        {
            serial_port_name.Items.Add(s);
        }
        serial_port_name.Text = "Select port";
        for (int i = 4800; i <= 38400; i = i * 2)
        {
            baud_rate.Items.Add(i);
        }
        for (int i = 57600; i <= 921600; i = i * 2)
        {
            baud_rate.Items.Add(i);
        }

        serial_port_name.DropDownStyle = ComboBoxStyle.DropDownList;
        baud_rate.SelectedIndex = 3;
        baud_rate.DropDownStyle = ComboBoxStyle.DropDownList;


    }

    private void serial_port_name_SelectedIndexChanged(object sender, EventArgs e)
    {
        if (serial_port_name.Text != "Select port")
        {
            configure_button.Enabled = true;
        }
    }

    private void configure_button_Click(object sender, EventArgs e)
    {
        serialPort1.PortName = serial_port_name.Text;
        serialPort1.BaudRate = Int32.Parse(baud_rate.Text);
        serialPort1.DataBits = 8;
        serialPort1.StopBits = StopBits.One;
        //serialPort1.Handshake = Handshake.None;
        serialPort1.ReceivedBytesThreshold = 44;
        serialPort1.ReadBufferSize = 8192;
        MessageBox.Show("Communication is set on " + serialPort1.PortName + " with baud rate: " + serialPort1.BaudRate);
        start_button.Enabled = true;
    }

    private void start_button_Click(object sender, EventArgs e)
    {
        if (serialPort1.IsOpen)
        {

            serialPort1.Close();
            start_button.Text = "START";
            read_button.Enabled = false;
            //read_write.Enabled = false;
            comport_status.Text = "DISCONNECTED";
        }
        else
        {
            serialPort1.Open();
            start_button.Text = "STOP";
            read_button.Enabled = true;
            //read_write.Enabled = true;
            comport_status.Text = "CONNECTED";
        }
    }

    private void quitToolStripMenuItem_Click(object sender, EventArgs e)
    {
        System.Windows.Forms.Application.Exit();
    }

    private void read_button_Click(object sender, EventArgs e)
    {
        bytes_to_read.Text = serialPort1.BytesToRead.ToString();
        read_data.Text = serialPort1.ReadExisting().ToString();
        read_data.Text += k.ToString() + "   ";
        if (buffer_old[0] == 4)
        {
            serialPort1.ReadByte();
        }
        serialPort1.Read(buffer, 0, 11);
        for (int j = 0; j < 11; j++)
        {
            read_data.Text += buffer[j].ToString() + "  ";
        }
        read_data.Text += "\n";
        k++;
        buffer_old = buffer;
    }

    private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {

        serialPort1 = (SerialPort)sender;
        number_of_bytes = serialPort1.BytesToRead.ToString();
        if (buffer_old[0] == 4)
        {
            serialPort1.ReadByte();
        }
        serialPort1.Read(buffer, 0, 11);
        buffer_old = buffer;
        this.Invoke(new EventHandler(displaytext));
        Thread.Sleep(20);
    }

    private void displaytext(object sender, EventArgs e)
    {
        checksum = 0;
        bytes_to_read.Text = number_of_bytes;
        read_data.Text += k.ToString() + "\t";
        for (int j = 0; j < 11; j++)
        {
            read_data.Text += buffer[j].ToString() + "  ";
            checksum += buffer[j]; 
        }
        checksum -= buffer[10];
        read_data.Text += "  \t" + checksum.ToString();
        read_data.Text += "\n";
        k++;
    }

}

}

Answer 2

请查看： If you must use .NET System.IO.Ports.SerialPort

Ben Voigt（作者）提供了一个很好的示例，说明了如何使用BaseStream的固有SerialPort成员，这对于使用基础Win32 API更为有效。

Port = new SerialPort("COM" + PORT_NUMBER.ToString()); 
...
private void ReadEvent()  
{      
    byte[] buffer = new byte[2000];  
    Action kickoffRead = null;  
    kickoffRead = (Action)(() => Port.BaseStream.BeginRead(buffer, 0, buffer.Length, delegate(IAsyncResult ar)  
    {  
        try  
        {  
            int count = Port.BaseStream.EndRead(ar);  
            byte[] dst = new byte[count];  
            Buffer.BlockCopy(buffer, 0, dst, 0, count);  
            RaiseAppSerialDataEvent(dst);  
        }  
        catch (Exception exception)  
        {  
            MessageBox.Show(ERROR == > " + exception.ToString());    
        }  
        kickoffRead();  
    }, null)); kickoffRead();  
}

致谢。

C＃中最快的串口通信？

2 个答案: