@Override
        public void onLeScan(BluetoothDevice bluetoothDevice, int i, byte[] bytes) {
          Log.d(TAG, "discovered device: " + bluetoothDevice.getName());
          Log.d(TAG, "device MAC: " + bluetoothDevice.getAddress());
          Home home = ((Alexandra) getApplicationContext()).getHome();
          if (home != null) {
            for (Gadget gadget : home.getGadgets()) {
              Log.d(TAG, "gadget MAC: " + gadget.getMAC());

              if (gadget.getMAC().equals(bluetoothDevice.getAddress())) {
                Log.d(TAG, "trying to connect GATT");
                gadget.setBluetoothGatt(
                    bluetoothDevice.connectGatt(
                        getApplicationContext(), true, gadget.getBluetoothGattCallback()));
              }
            }
          }
        }