为什么我从C#的串行端口中获得部分奇怪的值 [英] Why do I get partly strange values from serial port in C#

问题描述

我正在开发一个程序，该程序可以处理秤的数据.秤通过USB串行端口连接.我正在使用此问题中的代码:

I am working on a program that process data from a scale. The Scale is connected via USB serial Port. I am using the code from this Question: How to display weight from weighing scale into a textbox via serial port RS-232 or usb converter?. So the most important part is working. I get the weight from the scale as a string.

我的问题是，当秤将重量值(10/s)发送到计算机时，例如，我得到以下值:

My problem is, when the scale is sending the weight values (10/s) to the computer I am getting the following values for example:

13,0克；13,0克;12,9克;，8克;12,7克;2,6克;12,5克;12,4克;，3g;2,2克;12,1克;

13,0g; 13,0g; 12,9g; ,8g; 12,7g; 2,6g; 12,5g; 12,4g; ,3g; 2,2g; 12,1g;

您可以看到，某些值已损坏，有时第一个字符丢失，或者有时前两个字符...当我尝试使用秤制造商的其他程序读取值时，它的工作正常，所有值都是正确的.

You can see, some of the values are corrupted, sometimes the first character is missing, or sometimes the first 2 characters... When I try to read the values by using an other program from the scale manufacturer, its working fine, all values are correct.

那是什么问题?

我尝试了不同的波特率和其他设置，没有任何帮助.希望有人能帮助我.

I tried different baud rates and other settings, nothing helped. Hope someone can help me.

这是我用来从链接页面的串行端口读取数据的代码.

Here is the Code I use to read the data from serial port from the linked page.

using System;
using System.IO.Ports;          //<-- necessary to use "SerialPort"
using System.Windows.Forms;

namespace ComPortTests
{
    public partial class Form1 : Form
    {
        private SerialPort _serialPort;         //<-- declares a SerialPort Variable to be used throughout the form
        private const int BaudRate = 9600;      //<-- BaudRate Constant. 9600 seems to be the scale-units default value
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string[] portNames = SerialPort.GetPortNames();     //<-- Reads all available comPorts
            foreach (var portName in portNames)
            {
                comboBox1.Items.Add(portName);                  //<-- Adds Ports to combobox
            }
            comboBox1.SelectedIndex = 0;                        //<-- Selects first entry (convenience purposes)
        }

        private void button1_Click(object sender, EventArgs e)
        {
            //<-- This block ensures that no exceptions happen
            if(_serialPort != null && _serialPort.IsOpen)
                _serialPort.Close();
            if (_serialPort != null)
                _serialPort.Dispose();
            //<-- End of Block

            _serialPort = new SerialPort(comboBox1.Text, BaudRate, Parity.None, 8, StopBits.One);       //<-- Creates new SerialPort using the name selected in the combobox
            _serialPort.DataReceived += SerialPortOnDataReceived;       //<-- this event happens everytime when new data is received by the ComPort
            _serialPort.Open();     //<-- make the comport listen
            textBox1.Text = "Listening on " + _serialPort.PortName + "...\r\n";
        }

        private delegate void Closure();
        private void SerialPortOnDataReceived(object sender, SerialDataReceivedEventArgs serialDataReceivedEventArgs)
        {
            if (InvokeRequired)     //<-- Makes sure the function is invoked to work properly in the UI-Thread
                BeginInvoke(new Closure(() => { SerialPortOnDataReceived(sender, serialDataReceivedEventArgs); }));     //<-- Function invokes itself
            else
            {
                int dataLength = _serialPort.BytesToRead;
                byte[] data = new byte[dataLength];
                int nbrDataRead = _serialPort.Read(data, 0, dataLength);
                if (nbrDataRead == 0)
                    return;
                string str = System.Text.Encoding.UTF8.GetString(data);
                textBox1.Text = str.ToString();
            }
        }
}

推荐答案

我只需要添加以下几行，即可将值缓存在缓存文件中.

I just had to add the following lines to buffer the values in a cache file.

现在可以正常工作了！谢谢

Now it works fine! Thanks at all

        File.AppendAllText("buffer1.txt", str);

        string strnew = File.ReadLines("buffer1.txt").Last();

        textBox5.Text = strnew;

这篇关于为什么我从C#的串行端口中获得部分奇怪的值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！