Estoy escribiendo una aplicación host USB de Android para la cual estoy tratando de enumerar los dispositivos conectados con la tableta. Sigo el código en la documentación del host USB de Android en el sitio del desarrollador.

Mi código es el siguiente

AndroidUSBActivity

public class AndroidUSBActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    USBClass usb = new USBClass();
    ArrayList<String> deviceList = usb.GetUSBDevices(getBaseContext());
    final CharSequence[] items = deviceList.toArray(new CharSequence[deviceList.size()]);

    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Select a Reader");
    builder.setSingleChoiceItems(items, -1, new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int item) {
            String selectedDevice = (String) items[item];
            dialog.dismiss();

            TextView DeivceName = (TextView)findViewById(R.id.textView1);
            DeivceName.setText(selectedDevice);
        }
    });
    AlertDialog alert = builder.create();
    alert.show();
}
}

Clase USB

public class USBClass {


private static UsbManager mManager = null;
private static HashMap<String, UsbDevice> mdevices;
private static PendingIntent mPermissionIntent;
private static final String ACTION_USB_PERMISSION =
        "com.android.example.USB_PERMISSION";
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {

    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        if (ACTION_USB_PERMISSION.equals(action)) {
            synchronized (this) {
                UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
                if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
                    if(device != null){
                        //call method to set up device communication 
                        Log.i("usb", "permission granted for device " + device);
                    }
                } 
                else {
                    Log.i("usb", "permission denied for device " + device);
                }
            }
        }
    }
};   


public ArrayList<String> GetUSBDevices(Context context){
    mManager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
    mdevices = new HashMap<String, UsbDevice>();
    ArrayList<String> deviceList = new ArrayList<String>();
    mPermissionIntent = PendingIntent.getBroadcast(context, 0, new Intent("com.android.example.USB_PERMISSION"), 0);
    IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
    context.registerReceiver(mUsbReceiver, filter);


    // check for existing devices
    for (UsbDevice device :  mManager.getDeviceList().values()) {
        String deviceName = null;
        UsbDeviceConnection connection = null;
        if(device.getVendorId() == 0x0123){
            mManager.requestPermission(device, mPermissionIntent);
            connection = mManager.openDevice(device);
            byte rawBuf[] = new byte[255];
            int len = connection.controlTransfer(0x80, 0x06, 0x0302, 0x0409, rawBuf, 0x00FF, 60);
            rawBuf = Arrays.copyOfRange(rawBuf, 2, len);
            deviceName = new String(rawBuf);
            deviceList.add(deviceName);
            mdevices.put(deviceName, device);
        }

     }
    context.unregisterReceiver(mUsbReceiver);
    return deviceList;
}
}

LOGCAT

06-13 10:13:54.556: D/dalvikvm(2219): Late-enabling CheckJNI
06-13 10:13:54.586: I/System.out(2219): Sending WAIT chunk
06-13 10:13:54.586: W/ActivityThread(2219): Application bri.sample is waiting for the debugger on port 8100...
06-13 10:13:54.596: I/dalvikvm(2219): Debugger is active
06-13 10:13:54.786: I/System.out(2219): Debugger has connected
06-13 10:13:54.786: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:54.986: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:55.186: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:55.406: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:55.596: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:55.796: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:55.996: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:56.206: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:56.406: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:56.645: I/System.out(2219): waiting for debugger to settle...
06-13 10:13:56.846: I/System.out(2219): debugger has settled (1337)
06-13 10:13:57.116: E/UsbManager(2219): exception in UsbManager.openDevice
06-13 10:13:57.116: E/UsbManager(2219): java.lang.SecurityException: User has not given  permission to device   UsbDevice[mName=/dev/bus/usb/001/004,mVendorId=1254,mProductId=20758,mClass=0,mSubclass=0,mProtocol=0,mInterfaces=[Landroid.hardware.usb.UsbInterface;@41679100]
06-13 10:13:57.116: E/UsbManager(2219):     at android.os.Parcel.readException(Parcel.java:1327)
06-13 10:13:57.116: E/UsbManager(2219):     at android.os.Parcel.readException(Parcel.java:1281)
06-13 10:13:57.116: E/UsbManager(2219):     at android.hardware.usb.IUsbManager$Stub$Proxy.openDevice(IUsbManager.java:340)
06-13 10:13:57.116: E/UsbManager(2219):     at android.hardware.usb.UsbManager.openDevice(UsbManager.java:250)
06-13 10:13:57.116: E/UsbManager(2219):     at  bri.sample.USBClass.GetUSBDevices(USBClass.java:66)
06-13 10:13:57.116: E/UsbManager(2219):     at bri.sample.AndroidUSBActivity.onCreate(AndroidUSBActivity.java:19)
06-13 10:13:57.116: E/UsbManager(2219):     at android.app.Activity.performCreate(Activity.java:4465)
06-13 10:13:57.116: E/UsbManager(2219):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
06-13 10:13:57.116: E/UsbManager(2219):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
06-13 10:13:57.116: E/UsbManager(2219):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
06-13 10:13:57.116: E/UsbManager(2219):     at android.app.ActivityThread.access$600(ActivityThread.java:123)
06-13 10:13:57.116: E/UsbManager(2219):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
06-13 10:13:57.116: E/UsbManager(2219):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-13 10:13:57.116: E/UsbManager(2219):     at android.os.Looper.loop(Looper.java:137)
06-13 10:13:57.116: E/UsbManager(2219):     at android.app.ActivityThread.main(ActivityThread.java:4424)
06-13 10:13:57.116: E/UsbManager(2219):     at java.lang.reflect.Method.invokeNative(Native Method)
06-13 10:13:57.116: E/UsbManager(2219):     at java.lang.reflect.Method.invoke(Method.java:511)
06-13 10:13:57.116: E/UsbManager(2219):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-13 10:13:57.116: E/UsbManager(2219):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-13 10:13:57.116: E/UsbManager(2219):     at dalvik.system.NativeStart.main(Native Method)
06-13 10:13:57.566: D/dalvikvm(2219): threadid=1: still suspended after undo (sc=1 dc=1)
06-13 10:14:04.266: D/AndroidRuntime(2219): Shutting down VM
06-13 10:14:04.266: W/dalvikvm(2219): threadid=1: thread exiting with uncaught exception (group=0x40a531f8)
06-13 10:14:04.296: E/AndroidRuntime(2219): FATAL EXCEPTION: main
06-13 10:14:04.296: E/AndroidRuntime(2219): java.lang.RuntimeException: Unable to start activity ComponentInfo{bri.sample/bri.sample.AndroidUSBActivity}: java.lang.NullPointerException
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.ActivityThread.access$600(ActivityThread.java:123)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.os.Handler.dispatchMessage(Handler.java:99)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.os.Looper.loop(Looper.java:137)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.ActivityThread.main(ActivityThread.java:4424)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at java.lang.reflect.Method.invokeNative(Native Method)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at java.lang.reflect.Method.invoke(Method.java:511)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at dalvik.system.NativeStart.main(Native Method)
06-13 10:14:04.296: E/AndroidRuntime(2219): Caused by: java.lang.NullPointerException
06-13 10:14:04.296: E/AndroidRuntime(2219):     at bri.sample.USBClass.GetUSBDevices(USBClass.java:68)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at bri.sample.AndroidUSBActivity.onCreate(AndroidUSBActivity.java:19)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.Activity.performCreate(Activity.java:4465)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
06-13 10:14:04.296: E/AndroidRuntime(2219):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
06-13 10:14:04.296: E/AndroidRuntime(2219):     ... 11 more

PROBLEMA

Tengo el dispositivo conectado y luego instalo la aplicación. losprimera vez cuando la aplicación se inicia, se bloquea.