react-native-ble-manager

This is a porting of https://github.com/don/cordova-plugin-ble-central project to React Native.

Requirements

RN 0.40+

RN 0.30-0.39 supported until 2.4.3

Supported Platforms

• iOS 8+
• Android (API 19+)

Install

npm i --save react-native-ble-manager

After installing, you need to link the native library. You can either:

• Link native library with react-native link, or
• Link native library manually

Both approaches are described below.

Link Native Library with react-native link

react-native link react-native-ble-manager

After this step:

• iOS should be linked properly.
• Android will need one more step, you need to edit android/app/build.gradle:

// file: android/app/build.gradle
...

android {
    ...

    defaultConfig {
        ...
        minSdkVersion 18 // <--- make sure this is 18 or greater
        ...
    }
    ...
}

Link Native Library Manually

iOS

• Open the node_modules/react-native-ble-manager/ios folder and drag BleManager.xcodeproj into your Libraries group.
• Check the "Build Phases"of your project and add "libBleManager.a" in the "Link Binary With Libraries" section.

Android

Update Gradle Settings

// file: android/settings.gradle
...

include ':react-native-ble-manager'
project(':react-native-ble-manager').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-ble-manager/android')

Update Gradle Build

// file: android/app/build.gradle
...

android {
    ...

    defaultConfig {
        ...
        minSdkVersion 18 // <--- make sure this is 18 or greater
        ...
    }
    ...
}

dependencies {
    ...
    compile project(':react-native-ble-manager')
}

Register React Package

...
import it.innove.BleManagerPackage; // <--- import

public class MainApplication extends Application implements ReactApplication {

    ...

    @Override
    protected List<ReactPackage> getPackages() {
        return Arrays.<ReactPackage>asList(
            new MainReactPackage(),
            new BleManagerPackage() // <------ add the package
        );
    }

    ...
}

Note

• Remember to use the start method before anything.
• Avoid to connect/read/write to a peripheral during scan.
• Android API >= 23 require the ACCESS_COARSE_LOCATION permission to scan for peripherals. React Native >= 0.33 natively support PermissionsAndroid like in the example.

Basic Example

import React, { Component } from 'react';
import {
  AppRegistry,
  Text,
  View,
  TouchableHighlight,
  NativeAppEventEmitter,
  Platform,
  PermissionsAndroid
} from 'react-native';
import BleManager from 'react-native-ble-manager';

class BleExample extends Component {

    constructor(){
        super()

        this.state = {
            ble:null,
            scanning:false,
        }
    }

    componentDidMount() {
        BleManager.start({showAlert: false});
        this.handleDiscoverPeripheral = this.handleDiscoverPeripheral.bind(this);

        NativeAppEventEmitter
            .addListener('BleManagerDiscoverPeripheral', this.handleDiscoverPeripheral );
            
        if (Platform.OS === 'android' && Platform.Version >= 23) {
            PermissionsAndroid.checkPermission(PermissionsAndroid.PERMISSIONS.ACCESS_COARSE_LOCATION).then((result) => {
                if (result) {
                  console.log("Permission is OK");
                } else {
                  PermissionsAndroid.requestPermission(PermissionsAndroid.PERMISSIONS.ACCESS_COARSE_LOCATION).then((result) => {
                    if (result) {
                      console.log("User accept");
                    } else {
                      console.log("User refuse");
                    }
                  });
                }
          });
        }
    }

    handleScan() {
        BleManager.scan([], 30, true)
            .then((results) => {console.log('Scanning...'); });
    }

    toggleScanning(bool){
        if (bool) {
            this.setState({scanning:true})
            this.scanning = setInterval( ()=> this.handleScan(), 3000);
        } else{
            this.setState({scanning:false, ble: null})
            clearInterval(this.scanning);
        }
    }

    handleDiscoverPeripheral(data){
        console.log('Got ble data', data);
        this.setState({ ble: data })
    }

    render() {

        const container = {
            flex: 1,
            justifyContent: 'center',
            alignItems: 'center',
            backgroundColor: '#F5FCFF',
        }

        const bleList = this.state.ble
            ? <Text> Device found: {this.state.ble.name} </Text>
            : <Text>no devices nearby</Text>

        return (
            <View style={container}>
                <TouchableHighlight style={{padding:20, backgroundColor:'#ccc'}} onPress={() => this.toggleScanning(!this.state.scanning) }>
                    <Text>Scan Bluetooth ({this.state.scanning ? 'on' : 'off'})</Text>
                </TouchableHighlight>

                {bleList}
            </View>
        );
    }
}

AppRegistry.registerComponent('BleExample', () => BleExample);

Methods

start(options)

Init the module. Returns a Promise object.

Arguments

• options - JSON

The parameter is optional the configuration keys are:

• showAlert - Boolean - [iOS only] Show or hide the alert if the bluetooth is turned off during initialization
• forceLegacy - Boolean - [Android only] Force to use the LegacyScanManager

Examples

BleManager.start({showAlert: false})
  .then(() => {
    // Success code
    console.log('Module initialized');
  });

scan(serviceUUIDs, seconds)

Scan for availables peripherals. Returns a Promise object.

Arguments

• serviceUUIDs - Array of String - the UUIDs of the services to looking for. On Android the filter works only for 5.0 or newer.
• seconds - Integer - the amount of seconds to scan.
• allowDuplicates - Boolean - [iOS only] allow duplicates in device scanning

Examples

BleManager.scan([], 5, true)
  .then(() => {
    // Success code
    console.log('Scan started');
  });

stopScan()

Stop the scanning. Returns a Promise object.

Examples

BleManager.stopScan()
  .then(() => {
    // Success code
    console.log('Scan stopped');
  });

connect(peripheralId)

Attempts to connect to a peripheral. In many case if you can't connect you have to scan for the peripheral before. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral to connect, if succeeded contains the peripheral's services and characteristics infos.

Examples

BleManager.connect('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then((peripheralInfo) => {
    // Success code
    console.log('Connected');
    console.log(peripheralInfo);
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

disconnect(peripheralId)

Disconnect from a peripheral. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral to disconnect.

Examples

BleManager.disconnect('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then(() => {
    // Success code
    console.log('Disconnected');
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

enableBluetooth() [Android only]

Create the request to the user to activate the bluetooth. Returns a Promise object.

Examples

BleManager.enableBluetooth()
  .then(() => {
    // Success code
    console.log('The bluetooh is already enabled or the user confirm');
  })
  .catch((error) => {
    // Failure code
    console.log('The user refuse to enable bluetooth');
  });

checkState()

Force the module to check the state of BLE and trigger a BleManagerDidUpdateState event.

Examples

BleManager.checkState();

startNotification(peripheralId, serviceUUID, characteristicUUID)

Start the notification on the specified characteristic. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral.
• serviceUUID - String - the UUID of the service.
• characteristicUUID - String - the UUID of the characteristic.

Examples

BleManager.startNotification('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then(() => {
    // Success code
    console.log('Notification started');
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

stopNotification(peripheralId, serviceUUID, characteristicUUID)

Stop the notification on the specified characteristic. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral.
• serviceUUID - String - the UUID of the service.
• characteristicUUID - String - the UUID of the characteristic.

read(peripheralId, serviceUUID, characteristicUUID)

Read the current value of the specified characteristic. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral.
• serviceUUID - String - the UUID of the service.
• characteristicUUID - String - the UUID of the characteristic.

Examples

BleManager.read('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then((readData) => {
    // Success code
    console.log('Read: ' + readData);
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

write(peripheralId, serviceUUID, characteristicUUID, data, maxByteSize)

Write with response to the specified characteristic. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral.
• serviceUUID - String - the UUID of the service.
• characteristicUUID - String - the UUID of the characteristic.
• data - String - the data to write in Base64 format.
• maxByteSize - Integer - specify the max byte size before splitting message

To get the data into base64 format, you will need a library like base64-js. Install base64-js:

npm install base64-js --save

To format the data before calling the write function:

var base64 = require('base64-js');
var data = base64.fromByteArray(yourData);

Examples

BleManager.write('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', data)
  .then(() => {
    // Success code
    console.log('Write: ' + data);
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

writeWithoutResponse(peripheralId, serviceUUID, characteristicUUID, data, maxByteSize, queueSleepTime)

Write without response to the specified characteristic. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral.
• serviceUUID - String - the UUID of the service.
• characteristicUUID - String - the UUID of the characteristic.
• data - String - the data to write in Base64 format.
• maxByteSize - Integer - (Optional) specify the max byte size
• queueSleepTime - Integer - (Optional) specify the wait time before each write if the data is greater than maxByteSize

To get the data into base64 format, you will need a library like base64-js. Install base64-js:

npm install base64-js --save

To format the data before calling the write function:

var base64 = require('base64-js');
var data = base64.fromByteArray(yourData);

Examples

BleManager.writeWithoutResponse('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', data)
  .then(() => {
    // Success code
    console.log('Writed: ' + data);
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

getConnectedPeripherals(serviceUUIDs)

Return the connected peripherals. Returns a Promise object.

Arguments

• serviceUUIDs - Array of String - the UUIDs of the services to looking for.

Examples

BleManager.getConnectedPeripherals([])
  .then((peripheralsArray) => {
    // Success code
    console.log('Connected peripherals: ' + peripheralsArray.length);
  });

getDiscoveredPeripherals()

Return the discovered peripherals after a scan. Returns a Promise object.

Examples

BleManager.getDiscoveredPeripherals([])
  .then((peripheralsArray) => {
    // Success code
    console.log('Discovered peripherals: ' + peripheralsArray.length);
  });

removePeripheral(peripheralId)

Removes a disconnected peripheral from the cached list. It is useful if the device is turned off, because it will be re-discovered upon turning on again. Returns a Promise object.

Arguments

• peripheralId - String - the id/mac address of the peripheral.

isPeripheralConnected(peripheralId, serviceUUIDs)

Check whether a specific peripheral is connected and return true or false. Returns a Promise object.

Examples

BleManager.isPeripheralConnected('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', [])
  .then((isConnected) => {
    if (isConnected) {
      console.log('Peripheral is connected!');
    } else {
      console.log('Peripheral is NOT connected!');
    }
  });

Events

BleManagerStopScan

The scanning for peripherals is ended.

Arguments

• none

Examples

NativeAppEventEmitter.addListener(
    'BleManagerStopScan',
    () => {
        // Scanning is stopped
    }
);

BleManagerDidUpdateState

The BLE change state.

Arguments

• state - String - the new BLE state ('on'/'off').

Examples

NativeAppEventEmitter.addListener(
    'BleManagerDidUpdateState',
    (args) => {
        // The new state: args.state
    }
);

BleManagerDiscoverPeripheral

The scanning find a new peripheral.

Arguments

• id - String - the id of the peripheral
• name - String - the name of the peripheral

Examples

NativeAppEventEmitter.addListener(
    'BleManagerDiscoverPeripheral',
    (args) => {
        // The id: args.id
        // The name: args.name
    }
);

BleManagerDidUpdateValueForCharacteristic

A characteristic notify a new value.

Arguments

• peripheral - String - the id of the peripheral
• characteristic - String - the UUID of the characteristic
• value - String - the read value in Hex format

BleManagerConnectPeripheral

A peripheral was connected.

Arguments

• peripheral - String - the id of the peripheral

BleManagerDisconnectPeripheral

A peripheral was disconnected.

Arguments

• peripheral - String - the id of the peripheral