The Uniform Resource Identifier Beacon (UriBeacon) defines Bluetooth 4.0 Advertisement Data that contain Web URIs. URIBeacon provides a way for Bluetooth Low Energy devices to discover nearby URIs, for example, provides a way for a user to discover a short URL and then download it on their smartphone.

Dependencies:   BLE_API mbed nRF51822

Fork of BLE_PhysicalWeb by Bluetooth Low Energy

This example demonstrates how to set up and initialize a basic URI Beacon. For a more advanced example of using a URI beacon please see the BLE_PhysicalWeb project. The Google Github Page also gives a great description of what UriBeacons are and how to use them.

Basic Details

URI Beacons are a standard way of providing a URI link in a BLE advertising packet. Website URL's are the most popular URI's. The goal of URI Beacons are to act as a bridge between the physical and digital worlds. Since the URI can be any web capable link the possibilities for use are really endless. The UriBeacons can be thought of as a natural extension of and more useful version of QR codes.

Smartphone App Links

iPhone Physical Web app

Android App

Walkthrough of Physical Web application

Size of URI

The UriBeacon has one purpose, to advertise a web link. Because of the nature of BLE these web links have to be small. In order to provide a nice balance of small and useful the UriBeacon specification has abstracted out the representation of the URI prefix('http://www.', 'https://www.' , ...etc) and suffix ('.com','.org','.edu','.gov' ...etc) to a single byte each. Of the 27 bytes available for a usual BLE payload the UriBeacon has 19 bytes available for the URI. Of these 19bytes one byte must be given to the prefix. That leaves 18 bytes to fit the address and the suffix into. If the suffix used is not one of the standard ones in the UriBeacon specification then each letter will take up 1 byte instead of the entire suffix being abbreviated into a single byte.

Here are the acceptable abbreviations currently available


So for example the address "" would take up 8 bytes. Both "http://www." and ".com" are supported abbreviations so each will be shortened to 1 byte.

Number of BytesData
1"http://www." abbreviated
6"google", 1 byte for each letter
1".com/" abbreviated

An address like "" would take up 11 bytes. Notice that ".ly" is not a supported suffix, so each letter takes up 1 byte.

Number of BytesData
1"http://www." abbreviated

Even addresses with the suffix in the middle are abbreviated, ie "". Notice here that the '.com' is in the middle of an address, it is still shortened to just 1 byte.

Number of BytesData
1"http://www." abbreviated
1".com/" abbreviated

Using UriBeacons with mbed BLE API

Using the UriBeacon with the mbed API is rather simple. Just like any other BLE project you must first initialize the BLE baselayer by creating a ble object.


BLEDevice ble;

Then you pass the BLE object to a UriBeacon config service.


URIBeaconConfigService *uriBeaconConfig;
uriBeaconConfig = new URIBeaconConfigService(ble, "");

Optionally you can then adjust settings of the UriBeacon such as transmission power levels, grabbing verbose debug information and other handy dandy services.


/* Adjust the TX Power Level */
    const int8_t powerLevels[] = {-20, -4, 0, 10};
    uriBeaconConfig->setTxPowerLevels(powerLevels); // Set TX power levels, Lowest(-20), Low(-4), Medium(0), High(10)
    uriBeaconConfig->setTxPowerMode(URIBeaconConfigService::TX_POWER_MODE_LOW); // Set transmission in Low power mode

/* Adjust Beacon Period*/
setBeaconPeriod(1000); // Set beacon to advertise every 1000ms

Other UriBeacon Services

This is just the bare basics of how URI beacons work. There is also a configuration service that allows URI beacons to be updated, locked, and provides other management feature. That is beyond the scope of this example but details can be found in the Technical Details section below.

Technical Details

For more details on how URI beacons work please see these websites:
UriBeacon Github Project : the github home for all things UriBeacon (maintained by google)
UriBeacon Specification : lots of good technical details
UriBeacon configuration service - This is a service that pairs with the UriBeacon that allows changing the URI's, locking them, and some other cool features. This service is not detailed in this example application.
Android App : smartphone application to view nearby UriBeacons.
iOS App : Sample code for using UriBeacons with iOS.
The PhysicalWeb Project : a project that the UriBeacon is central to.

In case you're really interested here is a diagram that nicely sums up how the 27bytes of advertising data payload are used.

Thu Dec 10 07:42:47 2015 +0000
updating underlying libraries to the latest. ; also fixed a bug in main() in the loop which waits for initialization to complete.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rgrover1 16:1daa78939a3b 1 /* mbed Microcontroller Library
rgrover1 16:1daa78939a3b 2 * Copyright (c) 2006-2015 ARM Limited
rgrover1 16:1daa78939a3b 3 *
rgrover1 16:1daa78939a3b 4 * Licensed under the Apache License, Version 2.0 (the "License");
rgrover1 16:1daa78939a3b 5 * you may not use this file except in compliance with the License.
rgrover1 16:1daa78939a3b 6 * You may obtain a copy of the License at
rgrover1 16:1daa78939a3b 7 *
rgrover1 16:1daa78939a3b 8 *
rgrover1 16:1daa78939a3b 9 *
rgrover1 16:1daa78939a3b 10 * Unless required by applicable law or agreed to in writing, software
rgrover1 16:1daa78939a3b 11 * distributed under the License is distributed on an "AS IS" BASIS,
rgrover1 16:1daa78939a3b 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
rgrover1 16:1daa78939a3b 13 * See the License for the specific language governing permissions and
rgrover1 16:1daa78939a3b 14 * limitations under the License.
rgrover1 16:1daa78939a3b 15 */
rgrover1 16:1daa78939a3b 16
rgrover1 16:1daa78939a3b 17 #ifndef __BLE_CONFIG_PARAMS_PERSISTENCE_H__
rgrover1 16:1daa78939a3b 18 #define __BLE_CONFIG_PARAMS_PERSISTENCE_H__
rgrover1 16:1daa78939a3b 19
rgrover1 26:a2396234b4a8 20 #include "ble/services/URIBeaconConfigService.h"
rgrover1 16:1daa78939a3b 21
rgrover1 16:1daa78939a3b 22 /**
rgrover1 16:1daa78939a3b 23 * Generic API to load the URIBeacon configuration parameters from persistent
rgrover1 16:1daa78939a3b 24 * storage. If persistent storage isn't available, the persistenceSignature
rgrover1 16:1daa78939a3b 25 * member of params may be left un-initialized to the MAGIC, and this will cause
rgrover1 16:1daa78939a3b 26 * a reset to default values.
rgrover1 16:1daa78939a3b 27 *
rgrover1 16:1daa78939a3b 28 * @param[out] paramsP
rgrover1 17:e2c0a1696e39 29 * The parameters to be filled in from persistence storage. This
rgrover1 17:e2c0a1696e39 30 argument can be NULL if the caller is only interested in
rgrover1 17:e2c0a1696e39 31 discovering the persistence status of params.
rgrover1 17:e2c0a1696e39 32
rgrover1 17:e2c0a1696e39 33 * @return true if params were loaded from persistent storage and have usefully
rgrover1 17:e2c0a1696e39 34 * initialized fields.
rgrover1 16:1daa78939a3b 35 */
rgrover1 17:e2c0a1696e39 36 bool loadURIBeaconConfigParams(URIBeaconConfigService::Params_t *paramsP);
rgrover1 16:1daa78939a3b 37
rgrover1 16:1daa78939a3b 38 /**
rgrover1 16:1daa78939a3b 39 * Generic API to store the URIBeacon configuration parameters to persistent
rgrover1 16:1daa78939a3b 40 * storage. It typically initializes the persistenceSignature member of the
rgrover1 16:1daa78939a3b 41 * params to the MAGIC value to indicate persistence.
rgrover1 16:1daa78939a3b 42 *
rgrover1 17:e2c0a1696e39 43 * @note: the save operation may be asynchronous. It may be a short while before
rgrover1 17:e2c0a1696e39 44 * the request takes affect. Reading back saved configParams may not yield
rgrover1 17:e2c0a1696e39 45 * correct behaviour if attempted soon after a store.
rgrover1 17:e2c0a1696e39 46 *
rgrover1 16:1daa78939a3b 47 * @param[in/out] paramsP
rgrover1 16:1daa78939a3b 48 * The params to be saved; persistenceSignature member gets
rgrover1 16:1daa78939a3b 49 * updated if persistence is successful.
rgrover1 16:1daa78939a3b 50 */
rgrover1 17:e2c0a1696e39 51 void saveURIBeaconConfigParams(const URIBeaconConfigService::Params_t *paramsP);
rgrover1 16:1daa78939a3b 52
rgrover1 16:1daa78939a3b 53 #endif /* #ifndef __BLE_CONFIG_PARAMS_PERSISTENCE_H__*/