node

BLAST node

@blast/node is a library enabling usage of Web of Things (WoT) Thing Descriptions (TDs) for Bluetooth devices in Node.js.

Building this library produces 3 files inside the dist directory:

• blast.tds.js contains pre-defined Thing Descriptions of Bluetooth devices
• blast.node.js enables WoT interactions for Bluetooth devices in Node.js, by extending @node-wot/core with node-ble.
• blast.browser.js enables WoT interactions for Bluetooth devices in the web, by extending @node-wot/core with Web Bluetooth.

Install & build

To install and build @blast/core, open a terminal and execute the following commands from withing this directory.

1. install the dependencies yarn install
2. run the build script yarn build

Alternatively you could run yarn build:tds, yarn build:node, or yarn build:browser to only build the respective file.

Note

You might have to set yarn version using yarn set version berry before installing

Important

in order to access the Bluetooth HCI layer from Node.js, either you need to run node using sudo every time or execute sudo setcap cap_net_admin=ep $(eval readlink -f `which node`) first to give the node binary access to use Bluetooth HCI.

Usage

This section describes using the pre-defined TDs (of dist/blast.tds.cjs) with Node.js using dist/blast.node.cjs. For an example on how to use blast.browser.js see packages/web/. If you don't have a dist folder make sure to install & build first.

Example

import {createThing} from './dist/blast.node.cjs';
import {BleRgbController} from './dist/blast.tds.cjs';

const mac = 'BE5860018744';

const thing = await createThing(BleRgbController, mac);

await thing.writeProperty('colour', {R: 255, G: 0, B: 0});

API

createThing

Syntax

await createThing(td, id)

Definition

Creates a consumedThing from the provided Thing description and id

Parameters

Parameter	Description
td	Thing description of the thing to expose
id	The things identifier, as a string containing its mac address or the BluetoothDevice.id

Import

import {createThing} from 'blast.node.js'`

EddystoneHelpers

Object containg helper methods for interacting with Eddystone devices.

Import

import {EddystoneHelpers} from 'blast.node.js'`

Properties

Identifier	Description
EDDYSTONE_CONFIG_SERVICE	The BluetoothServiceUUID of the [Eddystone Configuration GATT Service](Eddystone Configuration GATT Service)
EDDYSTONE_CHARACTERISTICS	Maps BluetoothCharacteristicUUIDs to their respective Characteristic
parseCapabilities	Parses the response of a readProperty operation on the capabilities property and returns an object with human-readable values. e.g parseCapabilities(00040103000fe2ecf0f4f8fc0004) returns {   specVersion: 0,   maxSlots: 4,   maxEidPerSlot: 1,   isVarriableAdvIntervalSupported: true,   isVariableTxPowerSupported: true,   isUidSupported: true,   isUrlSupported: true,   isTlmSupported: true,   isEidSupported: true,   supportedTxPowerLevels: [     -30, -20, -16, -12,      -8,  -4,   0,   4   ] }
decodeAdvertisingData	Decodes the response of a readProperty operation on the AdvertisingData property and returns a human-readable string.
encodeAdvertisingData	Encodes a string using the Eddystone protocol specification for writing it to the AdvertisingData property.