- Code: Select all
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import javax.swing.JFrame;
import lejos.pc.comm.NXTCommLogListener;
import lejos.pc.comm.NXTConnector;
/**
* This is a PC sample. It connects to the NXT, and then
* sends an integer and waits for a reply, 100 times.
*
* Compile this program with javac (not nxjc), and run it
* with java.
*
* You need pccomm.jar on the CLASSPATH and the jfantom.dll
* DLL or liblibnxt.so shared library on the Java library path.
*
* Run the program by:
*
* java USBSend
*
* Your NXT should be running a sample such as USBReceive.
*
* @author Lawrie Griffiths
*
*/
public class BlueToothClass implements KeyListener {
public BlueToothClass() {
JFrame Window = new JFrame("My first JFrame Window!");
Window.setLocation(200,100);
Window.setSize(800,600);
Window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Window.setVisible(true);
Window.addKeyListener(this);
}
static NXTConnector conn = null;
static DataInputStream inDat = null;
static DataOutputStream outDat = null;
public static void main(String[] args) {
new BlueToothClass();
conn = new NXTConnector();
conn.addLogListener(new NXTCommLogListener(){
public void logEvent(String message) {
System.out.println("USBSend Log.listener: "+message);
}
public void logEvent(Throwable throwable) {
System.out.println("USBSend Log.listener - stack trace: ");
throwable.printStackTrace();
}
}
);
if (!conn.connectTo("usb://")){
System.err.println("No NXT found using USB");
System.exit(1);
}
inDat = new DataInputStream(conn.getInputStream());
outDat = new DataOutputStream(conn.getOutputStream());
}
@Override
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_W) {
try {
outDat.writeInt(50);
outDat.flush();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
@Override
public void keyReleased(KeyEvent arg0) {
// TODO Auto-generated method stub
}
@Override
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
}
and the NXT
- Code: Select all
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import lejos.nxt.LCD;
import lejos.nxt.comm.USB;
import lejos.nxt.comm.USBConnection;
/**
* Test of Java streams over USB.
* Run the PC example, USBSend, to send data.
*
* @author Lawrie Griffiths
*
*/
public class USBReceive {
public static void main(String [] args) throws Exception
{
LCD.drawString("waiting", 0, 0);
USBConnection conn = USB.waitForConnection();
DataOutputStream dOut = conn.openDataOutputStream();
DataInputStream dIn = conn.openDataInputStream();
while (true)
{
int b;
try
{
b = dIn.readInt();
}
catch (EOFException e)
{
break;
}
dOut.writeInt(-b);
dOut.flush();
LCD.drawInt(b,8,0,1);
}
dOut.close();
dIn.close();
conn.close();
}
}
and i get these errors when i press the W button
- Code: Select all
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at BlueToothClass.keyPressed(BlueToothClass.java:80)
at java.awt.Component.processKeyEvent(Component.java:6333)
at java.awt.Component.processEvent(Component.java:6152)
at java.awt.Container.processEvent(Container.java:2083)
at java.awt.Window.processEvent(Window.java:1835)
at java.awt.Component.dispatchEventImpl(Component.java:4737)
at java.awt.Container.dispatchEventImpl(Container.java:2141)
at java.awt.Window.dispatchEventImpl(Window.java:2482)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1836)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:712)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:990)
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:855)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:676)
at java.awt.Component.dispatchEventImpl(Component.java:4609)
at java.awt.Container.dispatchEventImpl(Container.java:2141)
at java.awt.Window.dispatchEventImpl(Window.java:2482)
at java.awt.Component.dispatchEvent(Component.java:4565)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:684)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:643)
at java.awt.EventQueue$1.run(EventQueue.java:641)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:657)
at java.awt.EventQueue$2.run(EventQueue.java:655)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:654)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
USBSend Log.listener: Failed to connect to the specified NXT
USBSend Log.listener: Failed to connect to any NXT
No NXT found using USB
the computer also doesn't find the nxt?? help?