import React, { useEffect, useState } from 'react';
import { DeviceEventEmitter } from 'react-native';
import BleManager from 'react-native-ble-manager';

const ConnectedDevice = () => {
  const [currentDevice, setCurrentDevice] = useState(null);
  const [receivedData, setReceivedData] = useState(null);

  // Initialize BleManager
  useEffect(() => {
    const initializeBleManager = async () => {
      await BleManager.start({ showAlert: false });
      console.log('Module initialized');
    };

    initializeBleManager();
  }, []);

  // Connect to a BLE device
  const connectToDevice = async (deviceId) => {
    try {
      // Connect to the device
      await BleManager.connect(deviceId);
      console.log(`Connected to device: ${deviceId}`);

      // Retrieve services and characteristics
      const peripheralInfo = await BleManager.retrieveServices(deviceId);
      setCurrentDevice(peripheralInfo);

      const serviceUUID = "6E400001-B5A3-F393-E0A9-E50E24DCCA9E";
      const characteristicUUID = "6E400003-B5A3-F393-E0A9-E50E24DCCA9E";

      // Start notifications for the characteristic
      await BleManager.startNotification(peripheralInfo.id, serviceUUID, characteristicUUID);
      console.log('Notification started for characteristic:', characteristicUUID);

    } catch (error) {
      console.error('Connection error:', error);
    }
  };

  // Listen for characteristic updates
  useEffect(() => {
    const characteristicValueUpdate = DeviceEventEmitter.addListener(
      'BleManagerDidUpdateValueForCharacteristic',
      (data) => {
        // Handle received data
        readCharacteristicFromEvent(data);
      }
    );

    // Cleanup the event listener on component unmount
    return () => {
      characteristicValueUpdate.remove();
    };
  }, []);

  // Read and process data from the characteristic
  const readCharacteristicFromEvent = (data) => {
    const { characteristic, value } = data;
    console.log('Received data:', value);
    setReceivedData(value);
  };

  return (
    // Your component JSX here
    <></>
  );
};

export default ConnectedDevice;

I am developing a React Native application using the react-native-ble-manager library to communicate with a Bluetooth Low Energy (BLE) device. While I can connect to the device successfully, I am having trouble receiving notifications from a specific characteristic. I have verified that the characteristic UUID is correct, but I am not receiving any data in the notification listener.

I have set up notifications for a BLE characteristic with the following UUID: 6E400003-B5A3-F393-E0A9-E50E24DCCA9E. Although the notification is successfully started (as confirmed by console logs), I do not receive any data when the device sends it.