use_002

ReadWrite.java  
/* 
 * Java libusb wrapper
 * Copyright (c) 2005-2006 Andreas Schläpfer <spandi at users.sourceforge.net>
 *
 * http://libusbjava.sourceforge.net
 * This library is covered by the LGPL, read LGPL.txt for details.
 */
package ch.ntb.usb.demo;

import ch.ntb.usb.Device;
import ch.ntb.usb.USB;
import ch.ntb.usb.USBException;

/**
 * Demo class to demonstrate simple read and write operations to an USB device.<br>
 * 
 * @author schlaepfer
 * 
 */
public class ReadWrite {

  private static void logData(byte[] data) {
    System.out.print("Data: ");
    for (int i = 0; i < data.length; i++) {
      System.out.print("0x" + Integer.toHexString(data[i] & 0xff) + " ");
    }
    System.out.println();
  }

  public static void main(String[] args) {
    // get a device instance with vendor id and product id
    Device dev = USB.getDevice((short) 0x8235, (short) 0x0222);
    try {
      // data to write to the device
      byte[] data = new byte[] { 0, 1, 2, 3 };
      // data read from the device
      byte[] readData = new byte[data.length];

      // open the device with configuration 1, interface 0 and without
      // altinterface
      // this will initialise Libusb for you
      dev.open(1, 0, -1);
      // write some data to the device
      // 0x03 is the endpoint address of the OUT endpoint 3 (from PC to
      // device)
      dev.writeInterrupt(0x03, data, data.length, 2000, false);
      // read some data from the device
      // 0x84 is the endpoint address of the IN endpoint 4 (from PC to
      // device)
      // bit 7 (0x80) is set in case of an IN endpoint
      dev.readInterrupt(0x84, readData, readData.length, 2000, false);
      // log the data from the device
      logData(readData);
      // close the device
      dev.close();
    } catch (USBException e) {
      // if an exception occures during connect or read/write an exception
      // is thrown
      e.printStackTrace();
    }
  }
}  

Examples

The first example (LogBus) uses the libusb share library directly to initialize libusb, get an object tree which represents the bus with associated devices and descriptors and print it to standard out.

The second example (ReadWrite) demonstrates how to get a device instance, read from and write to the device using the ch.ntb.usb.Device class. This class hides libusb specific methods and implements exceptions in case of error.