@Override
	public void onResume() {
		super.onResume();

		Intent intent = getIntent();
		if (mInputStream != null && mOutputStream != null) {
			return;
		}

		UsbAccessory[] accessories = mUsbManager.getAccessoryList();
		while( accessories == null ){
			accessories = mUsbManager.getAccessoryList();
		}
		UsbAccessory accessory = (accessories == null ? null : accessories[0]);
		if (accessory != null) {
			if (mUsbManager.hasPermission(accessory)) {
				openAccessory(accessory);
			} else {
				synchronized (mUsbReceiver) {
					if (!mPermissionRequestPending) {
						mUsbManager.requestPermission(accessory,
								mPermissionIntent);
						mPermissionRequestPending = true;
					}
				}
			}
		} else {
			Log.d(TAG, "mAccessory is null");
		}
	}


	private void openAccessory(UsbAccessory accessory) {
		mFileDescriptor = mUsbManager.openAccessory(accessory);
		while( mFileDescriptor == null);// inoue added
		if (mFileDescriptor != null) {
			mAccessory = accessory;
			FileDescriptor fd = mFileDescriptor.getFileDescriptor();
			mInputStream = new FileInputStream(fd);
			mOutputStream = new FileOutputStream(fd);
			Thread thread = new Thread(null, this, "DemoKit");
			thread.start();
			Log.d(TAG, "accessory opened");
			enableControls(true);
		} else {
			Log.d(TAG, "accessory open fail");
		}
	}