This example creates a BLE beacon: a method of advertising a small amount of information to nearby devices. The information doesn't have to be human-readable; it can be in a format that only an application can use. Beacons are very easy to set up: the code for all beacons is the same, and only the information you want to advertise - the beacon payload - needs to change. he canonical source for this example lives at https://github.com/ARMmbed/mbed-os-example-ble/tree/master/BLE_Beacon
source/main.cpp
- Committer:
- YJKIYOKAWA
- Date:
- 2020-03-19
- Revision:
- 82:7f3513808f75
- Parent:
- 76:652c2be531c7
- Child:
- 83:d0596095a535
File content as of revision 82:7f3513808f75:
/* 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::NON_CONNECTABLE_UNDIRECTED , ble::adv_interval_t(ble::millisecond_t(100)) ); _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[] = { 0x74, 0x27, 0x8B, 0xDA, 0xB6, 0x44, 0x45, 0x20, 0x8F, 0x0C, 0x72, 0x0E, 0xAF, 0x05, 0x99, 0x35 }; uint16_t major_number = 1; uint16_t minor_number = 3; uint16_t tx_power = 0xC8; uint16_t comp_id = 0x069e; 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; }