@awarns/ble

This module includes tasks to obtain information regarding nearby Bluetooth Low Energy (BLE) devices. This is useful to assess the existence of concrete devices nearby. Also, to build custom indoor localization and positioning systems based on BLE. Supports the iBeacon standard.

This plugin acts as a wrapper on top of the nativescript-context-apis plugin (from the same authors), offering BLE scanning tasks. Scan for nearby BLE devices even in background.

Install the plugin using the following command line instruction:

ns plugin add @awarns/ble

Usage

After installing and setting up this plugin, you'll have access to two different tasks to scan for Bluetooth Low Energy (BLE) devices seen nearby. The result, will be a BleScan record, described below.

Tasks

Task name	Description
acquirePhoneBleScan	Allows to perform single BLE scans for a given amount of time
acquireMultiplePhoneBleScan	Allows to repeatedly perform BLE scans. The duration of each scan can be controlled. Scans will happen for as long as there is execution time remaining (3 minutes max. or shortly before the next time-scheduled task execution, whatever occurs earlier)

Note: All the tasks require fine location permission, bluetooth scanning permission, active location services and active bluetooth adapter for their execution. Each task will automatically request what is missing during framework's initialization

Acquire a single BLE scan

To register this task for its use, you just need to import it and call its generator function inside your application's task list:

import { Task } from '@awarns/core/tasks';
import { acquirePhoneBleScanTask, BleScanMode } from '@awarns/ble';

export const demoTasks: Array<Task> = [
    acquirePhoneBleScanTask(
      /* optional */ { scanTime: 5000, scanMode: BleScanMode.BALANCED, iBeaconUuids: [] }
    ),
];

Task generator parameters:

Name	Type	Description
scanTime	number	The amount of time (in milliseconds) to be spent scanning. Defaults to 5000 (5s)
scanMode	BleScanMode	The BLE scan mode to use, see context-apis docs API section on BLE. Defaults to balanced mode
iBeaconUuids	Array<String>	Filters the scan results to only show devices broadcasting one of the given iBeacon UUID(s)

Task output events:

• bleScanAcquired

Example usage in the application task graph:

on(
  'startEvent',
  run('acquirePhoneBleScan')
    .every(1, 'minutes')
    .cancelOn('stopEvent')
);

on('bleScanAcquired', run('writeRecords'));

Note: To use the writeRecords task, the persistence package must be installed and configured. See persistence package docs.

Acquire BLE scans in batch

To register this task for its use, you just need to import it and call its generator function inside your application's task list:

import { Task } from '@awarns/core/tasks';
import { acquireMultiplePhoneBleScanTask, BleScanMode } from '@awarns/ble';

export const demoTasks: Array<Task> = [
    acquireMultiplePhoneBleScanTask(
      /* optional */ { scanTime: 5000, scanMode: BleScanMode.BALANCED, iBeaconUuids: [] }
    ),
];

Task generator parameters:

Name	Type	Description
scanTime	number	The amount of time (in milliseconds) to be spent scanning. Defaults to 5000 (5s)
scanMode	BleScanMode	The BLE scan mode to use, see context-apis docs API section on BLE. Defaults to balanced mode
iBeaconUuids	Array<String>	Filters the scan results to only show devices broadcasting one of the given iBeacon UUID(s)

Task output events:

• bleScanAcquired

Example usage in the application task graph:

on(
  'startEvent',
  run('acquireMultiplePhoneBleScan', { maxInterval: 10000 /* (Optional) Maximun interval between scans, unlimited by default */ })
    .every(1, 'minutes')
    .cancelOn('stopEvent')
);

on('bleScanAcquired', run('writeRecords'));

Note: To use the writeRecords task, the persistence package must be installed and configured. See persistence package docs.

Events

Name	Payload	Description
bleScanAcquired	BleScan | Array<BleScan>	Indicates that one or more new BLE scan results have been acquired

Records

BleScan

Property	Type	Description
id	string	Record's unique id
type	string	Always ble-scan
change	Change	Always none. Scan results are returned as a whole. Intermediate results are not reported
timestamp	Date	The local time when the scan was completed
seen	Array<BleDeviceInfo>	The devices seen during the scan. The list can be empty. For details on the properties of the BleDeviceInfo object, see context-apis API docs section on BLE

License

Apache License Version 2.0