Connecting the BLE weighing device by using device ID and get the displaying weight value of weighing device

Connect_and_get_value

const [connectedDevice, setConnectedDevice] = useState(null);
const [connectedDeviceServices, setConnectedDeviceServices] = useState(null);

  useEffect(() => {

    let moniterCharacteristic;
    let unSubscribeListener;

    if (connectedDevice && connectedDeviceServices) {
      // Device disconnect listener
      unSubscribeListener = connectedDevice.onDisconnected((error, device) => {
        alert("Device disconnected");
        setConnectedDevice(null);
        setConnectedDeviceServices(null);
      });

      connectedDeviceServices.forEach((service_data, index) => {
        connectedDevice
          .characteristicsForService(service_data.uuid)
          .then((characteristics) => {
            characteristics.forEach((characteristic_data) => {
              if (characteristic_data.isNotifiable) {
                moniterCharacteristic =
                  connectedDevice.monitorCharacteristicForService(
                    characteristic_data.serviceUUID,
                    characteristic_data.uuid,
                    (error, characteristic) => {
                      // error handling
                      if (error || !characteristic) {
                        alert(
                          "Something went wrong in moniter the characteristic"
                        );
                        return;
                      } else if (characteristic) {
                        var value = base64.decode(characteristic.value); // base64 is import from "react-native-base64" library for convert the base64 format to human readable string format
                        console.log(value) // Displaying value of weighing device
                      }
                    }
                  );
              }
            });
          })
          .catch((error) => {
            alert(
              "Something went wrong in get the characteristics for service"
            );
          });
      });
    }

    return () => {
      moniterCharacteristic && moniterCharacteristic.remove();
      unSubscribeListener && unSubscribeListener.remove();
    };

  }, [connectedDevice, connectedDeviceServices]);

//Connect BLE weighing device
  const connectWeightMachine = (deviceId) => {
    _BleManager
      .connectToDevice(deviceId, { autoConnect: false })
      .then((device) => {
        console.log("connected");
        console.log("device data - ",device)
        device.discoverAllServicesAndCharacteristics().then(() => {
          device
            .services()
            .then((device_services) => {
              console.log("device services", device_services)
              setConnectedDevice(device);
              setConnectedDeviceServices(device_services);
            })
            .catch((error) => {
              console.log("service error ", error);
              alert("Getting BLE service error");
            });
        });
      })
      .catch((error) => {
        console.log("connect device error ", error);
        alert("Connect to device error");
      });
  };