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.

Fri Nov 28 14:21:41 2014 +0000
Implementation for URIBeacon2; ;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
rgrover1 0:790a27ffc99b 1 /* mbed Microcontroller Library
rgrover1 0:790a27ffc99b 2 * Copyright (c) 2006-2013 ARM Limited
rgrover1 0:790a27ffc99b 3 *
rgrover1 0:790a27ffc99b 4 * Licensed under the Apache License, Version 2.0 (the "License");
rgrover1 0:790a27ffc99b 5 * you may not use this file except in compliance with the License.
rgrover1 0:790a27ffc99b 6 * You may obtain a copy of the License at
rgrover1 0:790a27ffc99b 7 *
rgrover1 0:790a27ffc99b 8 *
rgrover1 0:790a27ffc99b 9 *
rgrover1 0:790a27ffc99b 10 * Unless required by applicable law or agreed to in writing, software
rgrover1 0:790a27ffc99b 11 * distributed under the License is distributed on an "AS IS" BASIS,
rgrover1 0:790a27ffc99b 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
rgrover1 0:790a27ffc99b 13 * See the License for the specific language governing permissions and
rgrover1 0:790a27ffc99b 14 * limitations under the License.
rgrover1 0:790a27ffc99b 15 */
rgrover1 0:790a27ffc99b 16
rgrover1 0:790a27ffc99b 17 #include "mbed.h"
rgrover1 0:790a27ffc99b 18 #include "BLEDevice.h"
rgrover1 6:31b65d4ea67d 19 #include "URIBeacon2Service.h"
rgrover1 6:31b65d4ea67d 20 #include "DFUService.h"
rgrover1 6:31b65d4ea67d 21 #include "DeviceInformationService.h"
rgrover1 0:790a27ffc99b 22
rgrover1 0:790a27ffc99b 23 BLEDevice ble;
rgrover1 0:790a27ffc99b 24
rgrover1 6:31b65d4ea67d 25 void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason)
rgrover1 6:31b65d4ea67d 26 {
rgrover1 6:31b65d4ea67d 27 ble.startAdvertising();
rgrover1 6:31b65d4ea67d 28 }
rgrover1 0:790a27ffc99b 29
rgrover1 0:790a27ffc99b 30 int main(void)
rgrover1 0:790a27ffc99b 31 {
rgrover1 0:790a27ffc99b 32 ble.init();
rgrover1 6:31b65d4ea67d 33 ble.onDisconnection(disconnectionCallback);
rgrover1 0:790a27ffc99b 34
rgrover1 6:31b65d4ea67d 35 URIBeacon2Service uriBeacon(ble, "");
rgrover1 6:31b65d4ea67d 36 if (!uriBeacon.configuredSuccessfully()) {
rgrover1 6:31b65d4ea67d 37 error("failed to accommodate URI");
rgrover1 6:31b65d4ea67d 38 }
rgrover1 6:31b65d4ea67d 39 /* optional use of the API offered by URIBeacon2Service */
rgrover1 6:31b65d4ea67d 40 uriBeacon.setTxPowerLevel(URIBeacon2Service::TX_POWER_MODE_LOW, -4);
rgrover1 6:31b65d4ea67d 41 uriBeacon.useTxPowerMode(URIBeacon2Service::TX_POWER_MODE_LOW);
rgrover1 0:790a27ffc99b 42
rgrover1 6:31b65d4ea67d 43 /* Setup auxiliary services. */
rgrover1 6:31b65d4ea67d 44 DFUService dfu(ble); /* To allow over-the-air firmware udpates. optional. */
rgrover1 6:31b65d4ea67d 45 DeviceInformationService deviceInfo(ble, "ARM", "URIBeacon2", "SN1", "hw-rev1", "fw-rev1", "soft-rev1"); /* optional */
rgrover1 6:31b65d4ea67d 46
rgrover1 0:790a27ffc99b 47 ble.startAdvertising();
rgrover1 0:790a27ffc99b 48
rgrover1 0:790a27ffc99b 49 while (true) {
rgrover1 0:790a27ffc99b 50 ble.waitForEvent();
rgrover1 0:790a27ffc99b 51 }
rgrover1 0:790a27ffc99b 52 }