rn-ble-connect

This module let users connect with BLE devices and create own devices as BLE peripheral in React Native Expo.

API documentation

• Documentation for the main branch
• Documentation for the latest stable release

Installation in managed Expo projects

For managed Expo projects, please follow the installation instructions in the API documentation for the latest stable release. If you follow the link and there is no documentation available then this library is not yet usable within managed projects — it is likely to be included in an upcoming Expo SDK release.

Installation in bare React Native projects

For bare React Native projects, you must ensure that you have installed and configured the expo package before continuing.

Add the package to your npm dependencies

npm install rn-ble-connect

Configure for iOS

Run npx pod-install after installing the npm package.

Add bluetooth permissions in IOS info.plist

Configure for Android

Add bluetooth permissions in Android

• In AndroidManifest.xml add:

 <uses-permission android:name="android.permission.BLUETOOTH"/>
 <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>

Usage

Import

import * as RnBleConnect from "rn-ble-connect";

Set name (optional)

RnBleConnect.setName(name:string): void; This method sets the name of the device broadcast, before calling start.

RnBleConnect.setName('BLE_PERIPHERAL_NAME')

Get Name

RnBleConnect.getName(): string;

const peripheralName = RnBleConnect.getName()

Add Service

RnBleConnect.addService(UUID: string, primary: boolean): void;

RnBleConnect.addService('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', true) //for primary service
RnBleConnect.addService('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', false) //for non primary service

Add Characteristic

RnBleConnect.addCharacteristicToService(ServiceUUID:string, UUID:string, permissions:number, properties:number, characteristicData?: string): void;

RnBleConnect.addCharacteristicToService('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 16 | 1, 8) //this is a Characteristic with read and write permissions and notify property

Characteristic Properties and Permissions for Adnroid

https://developer.android.com/reference/android/bluetooth/BluetoothGattCharacteristic.html the link above is for permissions and properties constants info

Permissions:

• 1 - Readable
• 2 - Readable Encrypted
• 4 - Readable Encrypted MITM (Man-in-the-middle) Protection
• 16 - Writable
• 32 - Writable Encrypted
• 64 - Writable Encrypted MITM Protection
• 128 - Writable Signed
• 256 - Writable Signed MITM

Properties:

• 1 - Broadcastable
• 2 - Readable
• 4 - Writable without response
• 8 - Writable
• 16 - Supports notification
• 32 - Supports indication
• 64 - Signed Write
• 128 - Extended properties

Characteristic Properties and Permissions for IOS

Permissions:

• 1 - Readable
• 2 - Writable
• 4 - Readable Encrypted
• 8 - Writable Encrypted

Properties:

• 1 - Broadcastable
• 2 - Readable
• 4 - Writable without response
• 8 - Writable
• 10 - Supports notification
• 20 - Supports indication
• 40 - Signed Write
• 80 - Extended properties
• 100 - Notification Encrypted
• 200 - Indication Encrypted

Notify to devices

RnBleConnect.sendNotificationToDevices(ServiceUUID:string, CharacteristicUUID:string, data:byte[])

• note #1: in js it's not really a byte array, but an array of numbers
• note #2: the CharacteristicUUID must be of a Characteristic with notify property

RnBleConnect.sendNotificationToDevices('XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', [0x10,0x01,0xA1,0x80]) //sends a notification to all connected devices that, using the char uuid given

start Advertising

RnBleConnect.start(): Promise; note:use this only after adding services and characteristics

 RnBleConnect.start()
  .then(res => {
       console.log(res)
  }).catch(error => {
       console.log(error)
  })

In case of error, these are the error codes:

• 1 - Failed to start advertising as the advertise data to be broadcasted is larger than 31 bytes.
• 2 - Failed to start advertising because no advertising instance is available.
• 3 - Failed to start advertising as the advertising is already started.
• 4 - Operation failed due to an internal error.
• 5 - This feature is not supported on this platform.

stop Advertising

RnBleConnect.stop(): void;

 RnBleConnect.stop()