node-red-contrib-blebeacon-scanner/parser.js

node for BLE Beacon

/* ------------------------------------------------------------------
* node-beacon-scanner - parser.js
*
* Copyright (c) 2017-2018, Futomi Hatano, All rights reserved.
* Released under the MIT license
* Date: 2019-11-24
* ---------------------------------------------------------------- */
'use strict';

const mIbeacon = require('./parser-ibeacon.js');
const mEstimote = require('./parser-estimote.js');
const mEddystone = require('./parser-eddystone.js');

/* ------------------------------------------------------------------
* Constructor: EstimoteAdvertising()
* ---------------------------------------------------------------- */
const BeaconParser = function () {
	// Private properties
	this._ESTIMOTE_TELEMETRY_SERVICE_UUID = 'fe9a';
	this._ESTIMOTE_COMPANY_ID = 0x015d;
	this._EDDYSTONE_SERVICE_UUID = 'feaa';
};

/* ------------------------------------------------------------------
* Method: parse(peripheral)
* - peripheral: `Peripheral` object of the noble
* ---------------------------------------------------------------- */
BeaconParser.prototype.parse = function (peripheral) {
	let ad = peripheral.advertisement;
	let res = {
		id: peripheral.id,
		address: peripheral.address,
		localName: ad.localName || null,
		txPowerLevel: ad.txPowerLevel || null,
		rssi: peripheral.rssi
	};
	let manu = ad.manufacturerData;

	let beacon_type = this._detectBeaconType(peripheral);
	res['beaconType'] = beacon_type;
	let parsed = null;

	// iBeacon
	if (beacon_type === 'iBeacon') {
		parsed = mIbeacon.parse(peripheral);
		// Eddystone
	} else if (beacon_type === 'eddystoneUid') {
		parsed = mEddystone.parseUid(peripheral);
	} else if (beacon_type === 'eddystoneUrl') {
		parsed = mEddystone.parseUrl(peripheral);
	} else if (beacon_type === 'eddystoneTlm') {
		parsed = mEddystone.parseTlm(peripheral);
	} else if (beacon_type === 'eddystoneEid') {
		parsed = mEddystone.parseEid(peripheral);
		// Estimote
	} else if (beacon_type === 'estimoteTelemetry') {
		parsed = mEstimote.parseTelemetry(peripheral);
	} else if (beacon_type === 'estimoteNearable') {
		parsed = mEstimote.parseNearable(peripheral);
	} else if (beacon_type === 'other') {
		parsed = manu;
	}

	if (parsed) {
		res[beacon_type] = parsed;
		return res;
	} else {
		return null;
	}
};

BeaconParser.prototype._detectBeaconType = function (peripheral) {
	let ad = peripheral.advertisement;
	let manu = ad.manufacturerData;
	// Eddiystone
	if (ad.serviceData) {
		let eddystone_service = ad.serviceData.find((el) => {
			return el.uuid === this._EDDYSTONE_SERVICE_UUID;
		});
		if (eddystone_service && eddystone_service.data) {
			// https://github.com/google/eddystone/blob/master/protocol-specification.md
			let frame_type = eddystone_service.data.readUInt8(0) >>> 4;
			if (frame_type === 0b0000) {
				return 'eddystoneUid';
			} else if (frame_type === 0b0001) {
				return 'eddystoneUrl';
			} else if (frame_type === 0b0010) {
				return 'eddystoneTlm';
			} else if (frame_type === 0b0011) {
				return 'eddystoneEid';
			}
		}
	}
	// iBeacon
	if (manu && manu.length >= 4 && manu.readUInt32BE(0) === 0x4c000215) {
		return 'iBeacon';
	}
	// Estimote Telemetry
	if (ad.serviceData) {
		let telemetry_service = ad.serviceData.find((el) => {
			return el.uuid === this._ESTIMOTE_TELEMETRY_SERVICE_UUID;
		});
		if (telemetry_service && telemetry_service.data) {
			return 'estimoteTelemetry';
		}
	}
	// Estimote Nearable
	if (manu && manu.length >= 2 && manu.readUInt16LE(0) === this._ESTIMOTE_COMPANY_ID) {
		return 'estimoteNearable';
	}

	if (manu) {
		return 'other';
	}
	
	// Unknown
	return '';
};

module.exports = new BeaconParser();