Android Open Source - usbseriallib Usb Serial Lib

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License

The source code is released under:

GNU General Public License

Java Source Code

package com.ecgtheow.UsbSerialLib;
//w  w  w . j  a va2  s  .  c o  m
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;

import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbManager;
import android.util.Log;

public final class UsbSerialLib {
  private static final String TAG = "UsbSerialLib";

  private UsbManager manager;
  private PendingIntent permission_intent;
  private UsbDeviceConnectionEvent connection_event;
  private UsbDeviceReadEvent read_event;
  private ArrayList<UsbSerialDevice> connected_devices = new ArrayList<UsbSerialDevice>();
  
  /* See http://developer.android.com/guide/topics/usb/host.html
   * 
   * This string is registered with the PendingIntent permission_intent in initialize(), used
   * in the requestPermission() call, and monitored in the BroadcastReceiver usb_receiver().
   */
  private static final String ACTION_USB_PERMISSION = "com.ecgtheow.UsbSerialLib.USB_PERMISSION";
  
  public UsbSerialLib(Context context, UsbDeviceConnectionEvent connection_event, UsbDeviceReadEvent read_event) {
    manager = (UsbManager)context.getSystemService(Context.USB_SERVICE);
    permission_intent = PendingIntent.getBroadcast(context, 0, new Intent(ACTION_USB_PERMISSION), 0);
    this.connection_event = connection_event;
    this.read_event = read_event;
  }

  public void registerReceiver(Context context) {
    Log.d(TAG, "Registering USB receiver");
    
    IntentFilter permission_filter = new IntentFilter();
    permission_filter.addAction(ACTION_USB_PERMISSION);
    permission_filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
    permission_filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
    context.registerReceiver(usb_receiver, permission_filter);
  }
  
  public void unregisterReceiver(Context context) {
    Log.d(TAG, "Unregistering USB receiver");
    
    context.unregisterReceiver(usb_receiver);
  }
  
  public final int connectDevices() {
    int connect_count = 0;
    HashMap <String,UsbDevice> device_list = manager.getDeviceList();
    
    Log.d(TAG, String.format("%d devices found", device_list.size()));
    
    Iterator<UsbDevice> iter = device_list.values().iterator();
    while(iter.hasNext()) {
      UsbDevice device = iter.next();
      connectDevice(device);
    }
    
    return connect_count;
  }
  
  public final void connectDevice(UsbDevice device) {
    if(UsbSerialDeviceFactory.knownDevice(device)) {
      Log.d(TAG, String.format("Found a known device [0x%04x:0x%04x]", device.getVendorId(), device.getProductId()));
      manager.requestPermission(device, permission_intent);
    }
  }
  
  public final void disconnectDevice(UsbSerialDevice serial_device) {
    serial_device.disconnect();
  }
  
  private final BroadcastReceiver usb_receiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
      String action = intent.getAction();
      Log.d(TAG, String.format("Received action: %s", action));
      
      synchronized(this) {
        if(ACTION_USB_PERMISSION.equals(action)) {
          UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);

          if(intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
            /* Permission has been granted */
            if(device != null) {
              UsbSerialDevice serial_device = UsbSerialDeviceFactory.createDevice(device, read_event);
              if(serial_device != null) {
                Log.d(TAG, String.format("Created new serial device: %s at %s", serial_device.getName(), device.getDeviceName()));

                if(serial_device.connect(manager)) {
                  Log.d(TAG, String.format("Connected serial device: %s at %s", serial_device.getName(), device.getDeviceName()));
                  connected_devices.add(serial_device);

                  connection_event.onUsbDeviceConnected(serial_device);

                  serial_device.start();
                }
              } else {
                Log.d(TAG, String.format("Failed to create serial device for %s", device.getDeviceName()));
              }
            }
          } else {
            /* Permission not granted */
            Log.d(TAG, String.format("Permission denied for %s!", device.getDeviceName()));
          }
        } else if(UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
          UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
          if(device != null && UsbSerialDeviceFactory.knownDevice(device)) {
            /* Ask for permission to use it */
            Log.d(TAG, String.format("Device attached at %s", device.getDeviceName()));
            manager.requestPermission(device, permission_intent);
          }
        } else if(UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
          UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
          if(device != null) {
            /* clean up */
            for(UsbSerialDevice serial_device : connected_devices) {
              if(device.equals(serial_device.getDevice())) {
                serial_device.stop();
                if (connected_devices.remove(serial_device)) {
                  Log.d(TAG, String.format("Removed: %s at %s", serial_device.getName(), device.getDeviceName()));
                }
              }
            }
          }
        }
      }
    }
  };
}

Java Source Code List

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