串行端口轮询和数据处理

Question

我试图从传感器到微控制器的几个串口读取.每个串口将接收超过2000个测量值(每个测量值为7个字节,全部为十六进制).他们同时开枪.现在我正在从4个串口进行轮询.此外,我将每个测量值转换为String并将其附加到Stringbuilder.当我完成数据接收后,它们将被输入到文件中.问题是CPU消耗非常高,从80%到100%不等.

我浏览了一些文章并将Thread.Sleep(100)放在最后.它可以在没有数据时减少CPU时间.当BytesToRead小于100时,我还在每次轮询结束时放置Thread.Sleep.它只在一定程度上有所帮助.

有人可以提出一个解决方案来从串口轮询并处理我得到的数据吗？也许每次我得到的东西附加都会导致问题？

//I use separate threads for all sensors
private void SensorThread(SerialPort mySerialPort, int bytesPerMeasurement, TextBox textBox,     StringBuilder data)
    {
        textBox.BeginInvoke(new MethodInvoker(delegate() { textBox.Text = ""; }));

        int bytesRead;
        int t;
        Byte[] dataIn;

        while (mySerialPort.IsOpen)
        {
            try
            {
                if (mySerialPort.BytesToRead != 0)
                {
                  //trying to read a fix number of bytes
                    bytesRead = 0;
                    t = 0;
                    dataIn = new Byte[bytesPerMeasurement];
                    t = mySerialPort.Read(dataIn, 0, bytesPerMeasurement);
                    bytesRead += t;
                    while (bytesRead != bytesPerMeasurement)
                    {
                        t = mySerialPort.Read(dataIn, bytesRead, bytesPerMeasurement - bytesRead);
                        bytesRead += t;
                    }
                    //convert them into hex string
                    StringBuilder s = new StringBuilder();
                    foreach (Byte b in dataIn) { s.Append(b.ToString("X") + ","); }
                    var line = s.ToString();

                                            var lineString = string.Format("{0}  ----          {2}",
                                                      line,
                                                    mySerialPort.BytesToRead);
                    data.Append(lineString + "\r\n");//append a measurement to a huge Stringbuilder...Need a solution for this.

                    ////use delegate to change UI thread...
                    textBox.BeginInvoke(new MethodInvoker(delegate() { textBox.Text = line; }));

                    if (mySerialPort.BytesToRead <= 100) { Thread.Sleep(100); }
                }
            else{Thread.Sleep(100);}

            }
            catch (Exception ex)
            {
                //MessageBox.Show(ex.ToString());
            }
        }


    }

Answer 1

这不是一个好方法,它可以更好地处理DataReceived事件.

基本上有串口,有一个3阶段的过程,运作良好.

• 从串行端口接收数据
• 等到你有相关的数据块
• 解释数据

所以像

class DataCollector
{
    private readonly Action<List<byte>> _processMeasurement;
    private readonly string _port;
    private SerialPort _serialPort;
    private const int SizeOfMeasurement = 4;
    List<byte> Data = new List<byte>();

    public DataCollector(string port, Action<List<byte>> processMeasurement)
    {
        _processMeasurement = processMeasurement;
        _serialPort = new SerialPort(port);
        _serialPort.DataReceived +=SerialPortDataReceived;
    }

    private void SerialPortDataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        while(_serialPort.BytesToRead > 0)
        {
           var count = _serialPort.BytesToRead;
           var bytes = new byte[count];
           _serialPort.Read(bytes, 0, count);
           AddBytes(bytes);
        }
    }

    private void AddBytes(byte[] bytes)
    {
        Data.AddRange(bytes);
        while(Data.Count > SizeOfMeasurement)            
        {
            var measurementData = Data.GetRange(0, SizeOfMeasurement);
            Data.RemoveRange(0, SizeOfMeasurement);
            if (_processMeasurement != null) _processMeasurement(measurementData);
        }

    }
}

注意:添加字节会一直收集数据,直到您有足够的数据作为测量值,或者如果您获得数据突发,则将其分成单独的测量值....这样您就可以获得1个字节一次,2个下一个,以及接下来再做1个,然后将它转变为测量值.大多数情况下,如果你的微型发送它一个爆发,它将作为一个进来,但有时它将被分成2.

然后你可以做的地方

var collector = new DataCollector("COM1", ProcessMeasurement);

和

  private void ProcessMeasurement(List<byte> bytes)
            {
                // this will get called for every measurement, so then
                // put stuff into a text box.... or do whatever
            }