从Java读取Arduino太慢了

问题描述：

我正在尝试编写一个简单的Java程序，以显示在某些物理传感器上来自用户的刺激时，馈送给Arduino板的模拟输入。从Java读取Arduino太慢了

如果我使用Arduino程序本身并查看串行监视器，我会立即看到基于用户输入更新的模拟读取。但是，当从我的Java程序读取输入时，物理刺激与显示值之间会有显着的延迟（5-6秒）。

上传到Arduino的代码非常简单，通过一堆模拟端口的只是周期和打印数据：

void setup() { 
    Serial.begin(9600); 
    pinMode(30, OUTPUT); 
} 

void loop() 
    digitalWrite(30, HIGH); 

    for (int i = 0; i < 10; i++) { 
    int sensorValue = analogRead(i); 
    Serial.print(String(i) + ":"); 
    Serial.println(sensorValue); 
    } 
}

我使用的Java代码几乎完全从设置here，与示例复制我更新了端口名称以适用于我的系统（Mac OS X 10.10.3）的例外情况。

下面是Java代码：

import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import java.io.OutputStream; 
import gnu.io.CommPortIdentifier; 
import gnu.io.SerialPort; 
import gnu.io.SerialPortEvent; 
import gnu.io.SerialPortEventListener; 
import java.util.Enumeration; 


public class SerialTest implements SerialPortEventListener { 

    SerialPort serialPort; 

    /** The port we're normally going to use. */ 
    private static final String PORT_NAMES[] = { 
      "/dev/cu.usbmodem1411", 
      "/dev/cu.usbmodem1451", 
    }; 

    /** 
    * A BufferedReader which will be fed by a InputStreamReader 
    * converting the bytes into characters 
    * making the displayed results codepage independent 
    */ 
    private BufferedReader input; 

    /** The output stream to the port */ 
    private OutputStream output; 

    /** Milliseconds to block while waiting for port open */ 
    private static final int TIME_OUT = 2000; 

    /** Default bits per second for COM port. */ 
    private static final int DATA_RATE = 9600; 

    public void initialize() { 
     CommPortIdentifier portId = null; 
     Enumeration portEnum = CommPortIdentifier.getPortIdentifiers(); 

     //First, Find an instance of serial port as set in PORT_NAMES. 
     while (portEnum.hasMoreElements()) { 
      CommPortIdentifier currPortId = (CommPortIdentifier) portEnum.nextElement(); 
      for (String portName : PORT_NAMES) { 
       if (currPortId.getName().equals(portName)) { 
        portId = currPortId; 
        break; 
       } 
      } 
     } 
     if (portId == null) { 
      System.out.println("Could not find COM port."); 
      return; 
     } 

     try { 
      // open serial port, and use class name for the appName. 
      serialPort = (SerialPort) portId.open(this.getClass().getName(), 
        TIME_OUT); 

      // set port parameters 
      serialPort.setSerialPortParams(DATA_RATE, 
        SerialPort.DATABITS_8, 
        SerialPort.STOPBITS_1, 
        SerialPort.PARITY_NONE); 

      // open the streams 
      input = new BufferedReader(new InputStreamReader(serialPort.getInputStream())); 
      output = serialPort.getOutputStream(); 

      // add event listeners 
      serialPort.addEventListener(this); 
      serialPort.notifyOnDataAvailable(true); 
     } catch (Exception e) { 
      System.err.println(e.toString()); 
     } 
    } 

    /** 
    * This should be called when you stop using the port. 
    * This will prevent port locking on platforms like Linux. 
    */ 
    public synchronized void close() { 
     if (serialPort != null) { 
      serialPort.removeEventListener(); 
      serialPort.close(); 
     } 
    } 

    /** 
    * Handle an event on the serial port. Read the data and print it. 
    */ 
    public synchronized void serialEvent(SerialPortEvent oEvent) { 
     if (oEvent.getEventType() == SerialPortEvent.DATA_AVAILABLE) { 
      try { 
       String inputLine=input.readLine(); 
       System.out.println(inputLine); 
      } catch (Exception e) { 
       System.err.println(e.toString()); 
      } 
     } 
     // Ignore all the other eventTypes, but you should consider the other ones. 
    } 

    public static void main(String[] args) throws Exception { 
     SerialTest main = new SerialTest(); 
     main.initialize(); 
     Thread t=new Thread() { 
      public void run() { 
       //the following line will keep this app alive for 1000 seconds, 
       //waiting for events to occur and responding to them (printing incoming messages to console). 
       try {Thread.sleep(1000000);} catch (InterruptedException ie) {} 
      } 
     }; 
     t.start(); 
     System.out.println("Started"); 
    } 
}

所有程序所做的就是打印出来的Arduino的串口监视器的值，但它需要较长的方式（5-6秒）通过Java比它从做Arduino程序本身。

1）为什么会发生这种情况？
2）我该如何解决？

我想你也应该在这里发布你的问题 - http://arduino.stackexchange.com/ – TDG

我认为它属于这里，因为它似乎是一个Java问题，而不是一个Arduino之一，这是由事实证明Arduino IDE工作得很好，而且它不适用于Java。 – tam5

答

为我工作的答案是为我的Arduino代码添加一个delay方法。显然Java被输入速度所压倒。

当然，Java仍然可以以足够快的速度读取任何实际的差异。

从Java读取Arduino太慢了

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