从串行端口读取和写入给出 "OUTPUT_BUFFER_EMPTY"（可能 crc 计算和校验和不正确）

Question

我不知道我可能哪里错了，也不知道要更改什么才能使该程序能够与卡进行读写通信。

这是串口协议，帧的大致结构如下：

LEN---------------->帧字符总数

IND---------------->指标

ADDR_ST--------->站点地址

COD _OP-------->操作码

ADDR_DAT------->给出的地址

NR_DATI---------->运行数据数

DATI---------------->写操作数据

CRC---------------->检查校验和

这是我通过串口发送的帧：

byte miastringa[]={0x08,0x3f,0x00,0x42,0x00,0x01,0,cks};

这是代码：

import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.*;
//import javax.comm.*; // for SUN's serial/parallel port libraries
import gnu.io.*; // for rxtxSerial library

public class WriteReadSerialPort implements Runnable, SerialPortEventListener {
   static CommPortIdentifier portId;
   static CommPortIdentifier saveportId;
   static Enumeration        portList;
   InputStream           inputStream;
   SerialPort           serialPort;
   Thread           readThread;

byte cks= 0;
byte i;
byte cnt=0;
   byte miastringa[]={0x08,0x3f,0x00,0x42,0x00,0x01,0,cks}; 

   String  messageString ="0";

   static OutputStream      outputStream;
   static boolean        outputBufferEmptyFlag = false;

   public static void main(String[] args) {
      boolean           portFound = false;
      String           defaultPort;

      // determine the name of the serial port on several operating systems
      String osname = System.getProperty("os.name","").toLowerCase();
      if ( osname.startsWith("windows") ) {
         // windows
         defaultPort = "COM8";
      } else if (osname.startsWith("linux")) {
         // linux
        defaultPort = "/dev/ttyS0";
      } else if ( osname.startsWith("mac") ) {
         // mac
         defaultPort = "????";
      } else {
         System.out.println("Sorry, your operating system is not supported");
         return;
      }

      if (args.length > 0) {
         defaultPort = args[0];
      } 

      System.out.println("Set default port to "+defaultPort);

        // parse ports and if the default port is found, initialized the reader
      portList = CommPortIdentifier.getPortIdentifiers();
      while (portList.hasMoreElements()) {
         portId = (CommPortIdentifier) portList.nextElement();
         if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
            if (portId.getName().equals(defaultPort)) {
               System.out.println("Found port: "+defaultPort);
               portFound = true;
               // init reader thread
               WriteReadSerialPort reader = new WriteReadSerialPort();
            } 
         } 

      } 
      if (!portFound) {
         System.out.println("port " + defaultPort + " not found.");
      } 

   } 

   public void initwritetoport() {
      // initwritetoport() assumes that the port has already been opened and
      //    initialized by "public WriteReadSerialPort()"

      try {
         // get the outputstream
         outputStream = serialPort.getOutputStream();
      } catch (IOException e) {}

      try {
         // activate the OUTPUT_BUFFER_EMPTY notifier
         serialPort.notifyOnOutputEmpty(true);
      } catch (Exception e) {
         System.out.println("Error setting event notification");
         System.out.println(e.toString());
         System.exit(-1);
      }

   }

   public void writetoport() {
      System.out.println("Writing \""+messageString+"\" to "+serialPort.getName());
      try {
         // write string to serial port

           char[] crc_tab ={
                   0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
                   157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
                   35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
                   190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
                   70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
                   219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
                   101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
                   248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
                   140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205,
                   17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80,
                   175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238,
                   50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
                   202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
                   87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
                   233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
                   116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53};


         //protocol

           for(i=0; i<miastringa.length  ; i++) {
                cks += crc_tab[cks ^ miastringa[i]];

                cks-=cks;   
            }
             System.out.println("cks : "+ cks);

        for(cnt=0; cnt<miastringa.length;cnt++) {

            //miastringa[cnt++]=cks;
           // miastringa[0]=cnt;            
           // miastringa[cnt]=0;

        }
        System.out.println("miastringa : "+ miastringa);       
        System.out.println("cnt : "+ cnt);

        outputStream.write(miastringa);

      } catch (IOException e) {}
   }

   public WriteReadSerialPort() {
      // initalize serial port
      try {
         serialPort = (SerialPort) portId.open("SimpleReadApp", 4000);
      } catch (PortInUseException e) {}

      try {
         inputStream = serialPort.getInputStream();
      } catch (IOException e) {}

      try {
         serialPort.addEventListener(this);
      } catch (TooManyListenersException e) {}

      // activate the DATA_AVAILABLE notifier
      serialPort.notifyOnDataAvailable(true);

      try {
         // set port parameters
         serialPort.setSerialPortParams(19200, SerialPort.DATABITS_8, 
                     SerialPort.STOPBITS_1, 
                     SerialPort.PARITY_NONE);
      } catch (UnsupportedCommOperationException e) {}

      // start the read thread
      readThread = new Thread(this);
      readThread.start();

   }

   public void run() {
      // first thing in the thread, we initialize the write operation
      initwritetoport();
      try {
         while (true) {
            // write string to port, the serialEvent will read it
            writetoport();
            Thread.sleep(1000);
         }
      } catch (InterruptedException e) {}
   } 


   public void serialEvent(SerialPortEvent event) {
       System.out.println(".............."+event.getEventType());
      switch (event.getEventType()) {
      case SerialPortEvent.BI:
          System.out.println("BI");
      case SerialPortEvent.OE:
          System.out.println("OE");
      case SerialPortEvent.FE:
          System.out.println("FE");
      case SerialPortEvent.PE:
          System.out.println("PE");
      case SerialPortEvent.CD:
          System.out.println("CD");
      case SerialPortEvent.CTS:
          System.out.println("CTS");
      case SerialPortEvent.DSR:
          System.out.println("DSR");
      case SerialPortEvent.RI:
          System.out.println("RI");
      case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
          System.out.println("OUTPUT_BUFFER_EMPTY");
       break;
      case SerialPortEvent.DATA_AVAILABLE:
         // we get here if data has been received
         byte[] readBuffer = new byte[20];
         try {
            // read data
            while (inputStream.available() > 0) {
               int numBytes = inputStream.read(readBuffer);
            } 
            // print data
            String result  = new String(readBuffer);
            System.out.println("Read: "+result);
         } catch (IOException e) {}

         break;
      }
   }

控制台日志给我这个错误：

Writing "0" to //./COM8

cks : 0

miastringa : [B@32cff37c

cnt : 8

..............2

OUTPUT_BUFFER_EMPTY

感谢您的建议

Answer 1

我遇到了类似的问题，您必须将字符串拆分为多个部分并滚动浏览它们在我的例子中，以下代码有效：

Thread thread = new Thread() {

    @Override
    public void run() {



        while (true) {
            byte miastringacopy[] = {0X07, 0x3f, 0x01, 'b', 0x00, 0x08, 0x4f};
            byte miastringa1copy[] = {0X07, 0x3f, 0x01, 'b', 0x01, 0x08, 0x4e};
            byte miastringa2copy[] = {0X07, 0x3f, 0x01, 'b', 0x02, 0x08, 0x4d};
            byte miastringa3copy[] = {0X07, 0x3f, 0x01, 'b', 0x03, 0x08, 0x4c};

            if (co == 4) {

                co = 0;


                miastringa = miastringacopy;
                miastringa1 = miastringa1copy;
                miastringa2 = miastringa2copy;
                miastringa3 = miastringa3copy;
            }



            try {
                writeport();
                Thread.sleep(100);
                co++;


            } catch (InterruptedException e) {
                e.printStackTrace();
            }


        }

    }
};


UsbSerialInterface.UsbReadCallback mCallback = new UsbSerialInterface.UsbReadCallback() { //Defining a Callback which triggers whenever data is read.
        @Override
        public void onReceivedData(byte[] readbuffer) {
            // Get the port input stream.

        byte readbuffer2[];
        readbuffer2 = new byte[20];

        // read data
        int numBytes = readbuffer.length;
        if(numBytes>=15) {


            for (i = 0; i < readbuffer.length; i++) {
                readbuffer2[i] = readbuffer[i];

            }
            if (co == 0) {

                for (i = 0; i < 8; i++) {
                    outputBuffer1[i] = readbuffer2[i + 6];

                }

            }

            if (co == 1) {
                for (i = 0; i < 8; i++) {
                    outputBuffer1[i + 8] = readbuffer2[i + 6];

                }


            }


            if (co == 2) {
                for (i = 0; i < 8; i++) {
                    outputBuffer2[i] = readbuffer2[i + 6];

                }


            }

            if (co == 3) {

                for (i = 0; i < 8; i++) {
                    outputBuffer2[i + 8] = readbuffer2[i + 6];

                }


            }

从串行端口读取和写入给出 "OUTPUT_BUFFER_EMPTY"（可能 crc 计算和校验和不正确）

Read and Write from serial port gives "OUTPUT_BUFFER_EMPTY" (maybe crc calc and checksum is not correct)

java

serial-port

rxtx

read-write

crc64