在java中從串口讀取數據

Question

我想從連接到我的電腦的稱重橋讀取數據（這是重量），端口號爲com1。我搜索網頁，我可以連接到端口並讀取數據，但問題是數據不完整。

我越來越有點像下面

有145的權重是在稱重橋架，但我獲得這些符號。 這是我正在閱讀數據的代碼。

/* 
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* and open the template in the editor. 
*/ 
package readingports; 

import java.io.BufferedInputStream; 
import java.io.BufferedReader; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.util.Enumeration; 
import javax.comm.CommPortIdentifier; 
import javax.comm.SerialPort; 
import javax.comm.SerialPortEvent; 
import javax.comm.SerialPortEventListener; 

/** 
* 
* @author IamUsman 
*/ 
public class ReadingPorts implements SerialPortEventListener, Runnable { 

    static CommPortIdentifier portId; 
    static Enumeration portList; 
    static SerialPort port; 
    static InputStream inputStream; 
    static Thread readThread; 
    static byte buffer[]; 
    static BufferedReader br; 

    /** 
    * @param args the command line arguments 
    */ 
    public static void main(String[] args) { 
     // TODO code application logic here 
     portList = CommPortIdentifier.getPortIdentifiers(); 
     while (portList.hasMoreElements()) { 
      portId = (CommPortIdentifier) portList.nextElement(); 
      if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) { 
       if (portId.getName().equals("COM1")) { 
        if (!portId.isCurrentlyOwned()) { 
         ReadingPorts rp = new ReadingPorts(); 
        } else { 
         System.out.println("This port is already used by some other program"); 
        } 

       } 
      } 
     } 
    } 

    public ReadingPorts() { 
     try { 
      port = (SerialPort) portId.open("Custom", 500); 
      inputStream = port.getInputStream(); 
      br = new BufferedReader(new InputStreamReader(inputStream)); 
      System.out.println("** Connected To COM6 **"); 
      port.addEventListener(this); 
      port.notifyOnDataAvailable(true); 
      port.setSerialPortParams(9600, SerialPort.DATABITS_8, SerialPort.STOPBITS_1, SerialPort.PARITY_NONE); 
      port.setFlowControlMode(SerialPort.FLOWCONTROL_NONE); 
      port.enableReceiveTimeout(500); 
      System.out.println("................................"); 
      readThread = new Thread(this); 
      readThread.start(); 
     } catch (Exception ex) { 
      ex.printStackTrace(); 
     } 
    } 

    public void serialEvent(SerialPortEvent event) { 

     switch (event.getEventType()) { 

      case SerialPortEvent.DATA_AVAILABLE: 
       buffer = new byte[8]; 
       try { 
        while (inputStream.available() > 0) { 
         int numBytes = inputStream.read(buffer); 
         System.out.println(new String(buffer,0,numBytes)); 
        } 
       } catch (Exception ex) { 
        ex.printStackTrace(); 
       } 

       break; 

     } 




    } 

    @Override 
    public void run() { 
     try { 
      System.out.println("In Run"); 
      Thread.sleep(2000); 
     } catch (Exception ex) { 
      ex.printStackTrace();; 
     } 

    } 
} 

超級終端讀取正確的數據。

Answer 1

後理解你的代碼，也許你可以修改代碼以這樣的：

case SerialPortEvent.DATA_AVAILABLE: 
      try { 
       String inputLine=br.readLine(); 
       System.out.println(inputLine); 
      } catch (Exception ex) { 
       System.err.println(e.toString()); 
      } 

      break; 

，這2行移動到下面port.setSerialPortParams：

 inputStream = port.getInputStream(); 
     br = new BufferedReader(new InputStreamReader(inputStream));