Java Arduino找不到COM端口

我使用下面的代码示例与我的Arduino uno板进行通信。董事会使用COM40。但是当我从Eclipse运行这段代码时，我得到消息“找不到COM端口”。该板通过来自Arduino IDE的COM40进行连接。我的机器是64位Windows7

package control;
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/tty.usbserial-A9007UX1", // Mac OS X
                    "/dev/ttyACM0", // Raspberry Pi
        "/dev/ttyUSB0", // Linux
        "COM40", // Windows
};
/**
* 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() {
            // the next line is for Raspberry Pi and 
            // gets us into the while loop and was suggested here was suggested http://www.raspberrypi.org/phpBB3/viewtopic.php?f=81&t=32186
            System.setProperty("gnu.io.rxtx.SerialPorts", "/dev/ttyACM0");

    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");
}

---

}

此代码同时适用于Arduino和Raspberry Pi

---

但为了在Arduino中正常运行，您需要注释（或删除）这行代码“System.setProperty（“gnu.io.rxtx.SerialPorts”，“/dev/ttyACM0”）；”。这是public void initialize（）的第一行

Windows：我刚刚删除了“System.setProperty（“gnu.io.rxtx.SerialPorts”，“/dev/ttyACM0”）；”这行代码，它起作用了

如果你是COM40，那么你能不能也试试

“\\\\\\\.\\COM40”

？我试过了，但还是得到了同样的结果！您确定没有其他人在使用该端口吗？它是arduino IDE使用的端口。arduino板和IDE之间的通信很好，因为我可以上传草图并通过串行监视器查看输出。非常奇怪。不幸的是，我现在没有足够的时间进行调试，但我有一个很好的建议：试试。如果转到“示例”>“库”>“串行”，您应该能够修改其中一个示例以使用您的端口，并查看是否可以打开该端口。如果是，请进一步尝试读取/写入端口。如果一切正常，您可以在java项目中使用处理的串行库，或者查看它的实现（例如

C:\ProgramFiles（x86）\Processing-2.0.1\modes\java\libraries\serial

）。HTH请详细描述您的答案。您必须将其添加到答案中，而不是作为注释：）对于由此带来的不便，深表歉意。我是StackOverFlow的新手。