public JSONObject asJSONObject(BluetoothGatt gatt) {

    JSONObject json = asJSONObject();

    try {
      JSONArray servicesArray = new JSONArray();
      JSONArray characteristicsArray = new JSONArray();
      json.put("services", servicesArray);
      json.put("characteristics", characteristicsArray);

      if (connected && gatt != null) {
        for (BluetoothGattService service : gatt.getServices()) {
          servicesArray.put(UUIDHelper.uuidToString(service.getUuid()));

          for (BluetoothGattCharacteristic characteristic : service.getCharacteristics()) {
            JSONObject characteristicsJSON = new JSONObject();
            characteristicsArray.put(characteristicsJSON);

            characteristicsJSON.put("service", UUIDHelper.uuidToString(service.getUuid()));
            characteristicsJSON.put(
                "characteristic", UUIDHelper.uuidToString(characteristic.getUuid()));
            // characteristicsJSON.put("instanceId", characteristic.getInstanceId());

            characteristicsJSON.put("properties", Helper.decodeProperties(characteristic));
            // characteristicsJSON.put("propertiesValue", characteristic.getProperties());

            if (characteristic.getPermissions() > 0) {
              characteristicsJSON.put("permissions", Helper.decodePermissions(characteristic));
              // characteristicsJSON.put("permissionsValue", characteristic.getPermissions());
            }

            JSONArray descriptorsArray = new JSONArray();

            for (BluetoothGattDescriptor descriptor : characteristic.getDescriptors()) {
              JSONObject descriptorJSON = new JSONObject();
              descriptorJSON.put("uuid", UUIDHelper.uuidToString(descriptor.getUuid()));
              descriptorJSON.put("value", descriptor.getValue()); // always blank

              if (descriptor.getPermissions() > 0) {
                descriptorJSON.put("permissions", Helper.decodePermissions(descriptor));
                // descriptorJSON.put("permissionsValue", descriptor.getPermissions());
              }
              descriptorsArray.put(descriptorJSON);
            }
            if (descriptorsArray.length() > 0) {
              characteristicsJSON.put("descriptors", descriptorsArray);
            }
          }
        }
      }
    } catch (JSONException e) { // TODO better error handling
      e.printStackTrace();
    }

    return json;
  }
 @Override
 public void onServicesDiscovered(BluetoothGatt gatt, int status) {
   List<BluetoothGattService> services = gatt.getServices();
   Log.i("onServicesDiscovered", services.toString());
   gatt.readCharacteristic(services.get(1).getCharacteristics().get(0));
 }