iBeacon
iBeacon is an Apple technology based on BLE that you can use as an indoor positioning system. It allows iOS apps to track if the user enters a specific region and offers actions and notification aware of the user context.
The iBeacon class builds an advertising payload mimicking an iBeacon and assigns it to a given BLE interface.
Warning: To manufacture iBeacons, you must obtain a license from Apple. For more information, please see Apple's website. The license also grants access to the iBeacon's technical specification.
iBeacon class reference
Public Member Functions | |
iBeacon (BLE &_ble, LocationUUID_t uuid, uint16_t majNum, uint16_t minNum, uint8_t txP=0xC8, uint16_t compID=0x004C) | |
Construct an iBeacon::Payload and register it into Gap. More... |
iBeacon example
/* mbed Microcontroller Library
* Copyright (c) 2006-2015 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <events/mbed_events.h>
#include <mbed.h>
#include "ble/BLE.h"
#include "pretty_printer.h"
static events::EventQueue event_queue(/* event count */ 16 * EVENTS_EVENT_SIZE);
/** @deprecated This demo is deprecated and no replacement is currently available.
*/
MBED_DEPRECATED_SINCE(
"mbed-os-5.11",
"This demo is deprecated and no replacement is currently available."
)
class BeaconDemo : ble::Gap::EventHandler {
public:
BeaconDemo(BLE &ble, events::EventQueue &event_queue) :
_ble(ble),
_event_queue(event_queue),
_adv_data_builder(_adv_buffer) { }
void start() {
_ble.gap().setEventHandler(this);
_ble.init(this, &BeaconDemo::on_init_complete);
_event_queue.dispatch_forever();
}
private:
/**
* iBeacon payload builder.
*
* This data structure contains the payload of an iBeacon. The payload is
* built at construction time and application code can set up an iBeacon by
* injecting the raw field into the GAP advertising payload as a
* GapAdvertisingData::MANUFACTURER_SPECIFIC_DATA.
*/
union Payload {
/**
* Raw data of the payload.
*/
uint8_t raw[25];
struct {
/**
* Beacon manufacturer identifier.
*/
uint16_t companyID;
/**
* Packet ID; Equal to 2 for an iBeacon.
*/
uint8_t ID;
/**
* Length of the remaining data presents in the payload.
*/
uint8_t len;
/**
* Beacon UUID.
*/
uint8_t proximityUUID[16];
/**
* Beacon Major group ID.
*/
uint16_t majorNumber;
/**
* Beacon minor ID.
*/
uint16_t minorNumber;
/**
* Tx power received at 1 meter; in dBm.
*/
uint8_t txPower;
};
/**
* Assemble an iBeacon payload.
*
* @param[in] uuid Beacon network ID. iBeacon operators use this value
* to group their iBeacons into a single network, a single region and
* identify their organization among others.
*
* @param[in] majNum Beacon major group ID. iBeacon exploitants may use
* this field to divide the region into subregions, their network into
* subnetworks.
*
* @param[in] minNum Identifier of the Beacon in its subregion.
*
* @param[in] transmitPower Measured transmit power of the beacon at 1
* meter. Scanners use this parameter to approximate the distance
* to the beacon.
*
* @param[in] companyIDIn ID of the beacon manufacturer.
*/
Payload(
const uint8_t *uuid,
uint16_t majNum,
uint16_t minNum,
uint8_t transmitPower,
uint16_t companyIDIn
) : companyID(companyIDIn),
ID(0x02),
len(0x15),
majorNumber(__REV16(majNum)),
minorNumber(__REV16(minNum)),
txPower(transmitPower)
{
memcpy(proximityUUID, uuid, 16);
}
};
/** Callback triggered when the ble initialization process has finished */
void on_init_complete(BLE::InitializationCompleteCallbackContext *params) {
if (params->error != BLE_ERROR_NONE) {
printf("Ble initialization failed.");
return;
}
print_mac_address();
start_advertising();
}
void start_advertising() {
/* Create advertising parameters and payload */
ble::AdvertisingParameters adv_parameters(
ble::advertising_type_t::CONNECTABLE_UNDIRECTED,
ble::adv_interval_t(ble::millisecond_t(1000))
);
_adv_data_builder.setFlags();
/**
* The Beacon payload has the following composition:
* 128-Bit / 16byte UUID = E2 0A 39 F4 73 F5 4B C4 A1 2F 17 D1 AD 07 A9 61
* Major/Minor = 0x1122 / 0x3344
* Tx Power = 0xC8 = 200, 2's compliment is 256-200 = (-56dB)
*
* Note: please remember to calibrate your beacons TX Power for more accurate results.
*/
static const uint8_t uuid[] = { 0xE2, 0x0A, 0x39, 0xF4, 0x73, 0xF5, 0x4B, 0xC4,
0xA1, 0x2F, 0x17, 0xD1, 0xAD, 0x07, 0xA9, 0x61 };
uint16_t major_number = 1122;
uint16_t minor_number = 3344;
uint16_t tx_power = 0xC8;
uint16_t comp_id = 0x004C;
Payload ibeacon(uuid, major_number, minor_number, tx_power, comp_id);
_adv_data_builder.setManufacturerSpecificData(ibeacon.raw);
/* Setup advertising */
ble_error_t error = _ble.gap().setAdvertisingParameters(
ble::LEGACY_ADVERTISING_HANDLE,
adv_parameters
);
if (error) {
print_error(error, "_ble.gap().setAdvertisingParameters() failed");
return;
}
error = _ble.gap().setAdvertisingPayload(
ble::LEGACY_ADVERTISING_HANDLE,
_adv_data_builder.getAdvertisingData()
);
if (error) {
print_error(error, "_ble.gap().setAdvertisingPayload() failed");
return;
}
/* Start advertising */
error = _ble.gap().startAdvertising(ble::LEGACY_ADVERTISING_HANDLE);
if (error) {
print_error(error, "_ble.gap().startAdvertising() failed");
return;
}
}
private:
/* Event handler */
void onDisconnectionComplete(const ble::DisconnectionCompleteEvent&) {
_ble.gap().startAdvertising(ble::LEGACY_ADVERTISING_HANDLE);
}
private:
BLE &_ble;
events::EventQueue &_event_queue;
uint8_t _adv_buffer[ble::LEGACY_ADVERTISING_MAX_SIZE];
ble::AdvertisingDataBuilder _adv_data_builder;
};
/** Schedule processing of events from the BLE middleware in the event queue. */
void schedule_ble_events(BLE::OnEventsToProcessCallbackContext *context) {
event_queue.call(Callback<void()>(&context->ble, &BLE::processEvents));
}
int main()
{
BLE &ble = BLE::Instance();
ble.onEventsToProcess(schedule_ble_events);
BeaconDemo demo(ble, event_queue);
demo.start();
return 0;
}
Note: You can find more information at the Apple iBeacon page.