React Native BLE communication module
marcosinigaglia Merge pull request #380 from drash-course/master
Fix: The app crashes when a characteristic with 0x value is discovered
Latest commit 6b541e4 Sep 13, 2018

README.md

react-native-ble-manager

npm version npm downloads GitHub issues

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 19 // <--- make sure this is 19 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 19 // <--- make sure this is 19 or greater
        ...
    }
    ...
}

dependencies {
    ...
    compile project(':react-native-ble-manager')
}
Update Android Manifest
// file: android/app/src/main/AndroidManifest.xml
...
    <uses-permission android:name="android.permission.BLUETOOTH"/>
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
...
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.
  • If you have problem with old devices try 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.
  • Before write, read or start notification you need to call retrieveServices method

Example

The easiest way to test is simple make your AppRegistry point to our example component, like this:

// in your index.ios.js or index.android.js
import React, { Component } from 'react';
import {
  AppRegistry,
} from 'react-native';
import App from 'react-native-ble-manager/example/App' //<-- simply point to the example js!

AppRegistry.registerComponent('MyAwesomeApp', () => App);

Or, you can still look into the whole example folder for a standalone project.

Methods

start(options)

Init the module. Returns a Promise object. Don't call this multiple times.

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
  • restoreIdentifierKey - String - [iOS only] Unique key to use for CoreBluetooth state restoration
  • forceLegacy - Boolean - [Android only] Force to use the LegacyScanManager

Examples

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

scan(serviceUUIDs, seconds, allowDuplicates, scanningOptions)

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
  • scanningOptions - JSON - [Android only] after Android 5.0, user can control specific ble scan behaviors:

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.

In iOS, attempts to connect to a peripheral do not time out (please see Apple's doc), so you might need to set a timer explicitly if you don't want this behavior.

Arguments

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

Examples

BleManager.connect('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then(() => {
    // Success code
    console.log('Connected');
  })
  .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 bluetooth 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, you need to call retrieveServices method before. 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, you need to call retrieveServices method before. 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);

    const buffer = Buffer.Buffer.from(readData);    //https://github.com/feross/buffer#convert-arraybuffer-to-buffer
    const sensorData = buffer.readUInt8(1, true);
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

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

Write with response to the specified characteristic, you need to call retrieveServices method before. 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 - Byte array - the data to write.
  • maxByteSize - Integer - specify the max byte size before splitting message

Data preparation

If your data is not in byte array format you should convert it first. For strings you can use convert-string or other npm package in order to achieve that. Install the package first:

npm install convert-string

Then use it in your application:

// Import/require in the beginning of the file
import { stringToBytes } from 'convert-string';
// Convert data to byte array before write/writeWithoutResponse
const data = stringToBytes(yourStringData);

Feel free to use other packages or google how to convert into byte array if your data has other format.

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, you need to call retrieveServices method before. 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 - Byte array - the data to write.
  • 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

Data preparation

If your data is not in byte array format check info for the write function above.

Example

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);
  });

readRSSI(peripheralId)

Read the current value of the RSSI. Returns a Promise object.

Arguments

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

Examples

BleManager.readRSSI('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then((rssi) => {
    // Success code
    console.log('Current RSSI: ' + rssi);
  })
  .catch((error) => {
    // Failure code
    console.log(error);
  });

requestConnectionPriority(peripheralId, connectionPriority) [Android only API 21+]

Request a connection parameter update. Returns a Promise object.

Arguments

  • peripheralId - String - the id/mac address of the peripheral.
  • connectionPriority - Integer - the connection priority to be requested, as follows:
    • 0 - balanced priority connection
    • 1 - high priority connection
    • 2 - low power priority connection

Examples

BleManager.requestConnectionPriority('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 1)
.then((status) => {
  // Success code
  console.log('Requested connection priority');
})
.catch((error) => {
  // Failure code
  console.log(error);
});

requestMTU(peripheralId, mtu) [Android only API 21+]

Request an MTU size used for a given connection. Returns a Promise object.

Arguments

  • peripheralId - String - the id/mac address of the peripheral.
  • mtu - Integer - the MTU size to be requested in bytes.

Examples

BleManager.requestMTU('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 512)
.then((mtu) => {
  // Success code
  console.log('MTU size changed to ' + mtu + ' bytes');
})
.catch((error) => {
  // Failure code
  console.log(error);
});

retrieveServices(peripheralId)

Retrieve the peripheral's services and characteristics. Returns a Promise object.

Arguments

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

Examples

BleManager.retrieveServices('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then((peripheralInfo) => {
    // Success code
    console.log('Peripheral info:', peripheralInfo);
  });  

refreshCache(peripheralId) [Android only]

refreshes the peripheral's services and characteristics cache Returns a Promise object.

Arguments

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

Examples

BleManager.refreshCache('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX')
  .then((peripheralInfo) => {
    // Success code
    console.log('cache refreshed!')
  })
  .cache((error) => {
    console.error(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);
  });

createBond(peripheralId) [Android only]

Start the bonding (pairing) process with the remote device. Returns a Promise object. The promise is resolved when either new bond successfully created or bond already existed, otherwise it will be rejected.

Examples

BleManager.createBond(peripheralId)
  .then(() => {
    console.log('createBond success or there is already an existing one');
  })
  .catch(() => {
    console.log('fail to bond');
  })

removeBond(peripheralId) [Android only]

Remove a paired device. Returns a Promise object.

Examples

BleManager.removeBond(peripheralId)
  .then(() => {
    console.log('removeBond success');
  })
  .catch(() => {
    console.log('fail to remove the bond');
  })

getBondedPeripherals() [Android only]

Return the bonded peripherals. Returns a Promise object.

Examples

BleManager.getBondedPeripherals([])
  .then((bondedPeripheralsArray) => {
    // Each peripheral in returned array will have id and name properties
    console.log('Bonded peripherals: ' + bondedPeripheralsArray.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) [Android only]

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

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

BleManagerDidUpdateState

The BLE change state.

Arguments

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

Examples

bleManagerEmitter.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
  • rssi - Number - the RSSI value
  • advertising - JSON - the advertising payload, according to platforms:
    • [Android] contains the raw bytes and data (Base64 encoded string)
    • [iOS] contains a JSON object with different keys according to Apple's doc, here are some examples:
      • kCBAdvDataChannel - Number
      • kCBAdvDataIsConnectable - Number
      • kCBAdvDataLocalName - String
      • kCBAdvDataManufacturerData - JSON - contains the raw bytes and data (Base64 encoded string)

Examples

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

BleManagerDidUpdateValueForCharacteristic

A characteristic notify a new value.

Arguments

  • valueArray — the read value
  • peripheralString — the id of the peripheral
  • characteristicString — the UUID of the characteristic
  • serviceString — the UUID of the characteristic

Event will only be emitted after successful startNotification.

Example

import { bytesToString } from 'convert-string';

async function connectAndPrepare(peripheral, service, characteristic) {
  // Connect to device
  await BleManager.connect(peripheral);
  // Before startNotification you need to call retrieveServices
  await BleManager.retrieveServices(peripheral);
  // To enable BleManagerDidUpdateValueForCharacteristic listener
  await BleManager.startNotification(peripheral, service, characteristic);
  // Add event listener
  bleManagerEmitter.addListener(
    'BleManagerDidUpdateValueForCharacteristic',
    ({ value, peripheral, characteristic, service }) => {
        // Convert bytes array to string
        const data = bytesToString(value);
        console.log(`Recieved ${data} for characteristic ${characteristic}`);
    }
  );
  // Actions triggereng BleManagerDidUpdateValueForCharacteristic event
}

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