This is a fork of mbed-os-example-ble-HeartRate maintained for Sequana compatibility. This application transmits a heart rate value using the Bluetooth SIG Heart Rate Profile. The heart rate value is provided by the application itself, not by a sensor, so that you don't have to get a sensor just to run the example. The canonical source for this example lives at https://github.com/ARMmbed/mbed-os-example-ble/tree/master/BLE_HeartRate
Diff: source/main.cpp
- Revision:
- 0:b283842072f8
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/source/main.cpp Tue Feb 12 14:03:29 2019 +0000 @@ -0,0 +1,173 @@ +/* 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 "ble/gap/Gap.h" +#include "ble/services/HeartRateService.h" +#include "pretty_printer.h" + +const static char DEVICE_NAME[] = "Heartrate"; + +static events::EventQueue event_queue(/* event count */ 16 * EVENTS_EVENT_SIZE); + +class HeartrateDemo : ble::Gap::EventHandler { +public: + HeartrateDemo(BLE &ble, events::EventQueue &event_queue) : + _ble(ble), + _event_queue(event_queue), + _led1(LED1, 1), + _connected(false), + _hr_uuid(GattService::UUID_HEART_RATE_SERVICE), + _hr_counter(100), + _hr_service(ble, _hr_counter, HeartRateService::LOCATION_FINGER), + _adv_data_builder(_adv_buffer) { } + + void start() { + _ble.gap().setEventHandler(this); + + _ble.init(this, &HeartrateDemo::on_init_complete); + + _event_queue.call_every(500, this, &HeartrateDemo::blink); + _event_queue.call_every(1000, this, &HeartrateDemo::update_sensor_value); + + _event_queue.dispatch_forever(); + } + +private: + /** 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(); + _adv_data_builder.setAppearance(ble::adv_data_appearance_t::GENERIC_HEART_RATE_SENSOR); + _adv_data_builder.setLocalServiceList(mbed::make_Span(&_hr_uuid, 1)); + _adv_data_builder.setName(DEVICE_NAME); + + /* Setup advertising */ + + ble_error_t error = _ble.gap().setAdvertisingParameters( + ble::LEGACY_ADVERTISING_HANDLE, + adv_parameters + ); + + if (error) { + printf("_ble.gap().setAdvertisingParameters() failed\r\n"); + return; + } + + error = _ble.gap().setAdvertisingPayload( + ble::LEGACY_ADVERTISING_HANDLE, + _adv_data_builder.getAdvertisingData() + ); + + if (error) { + printf("_ble.gap().setAdvertisingPayload() failed\r\n"); + return; + } + + /* Start advertising */ + + error = _ble.gap().startAdvertising(ble::LEGACY_ADVERTISING_HANDLE); + + if (error) { + printf("_ble.gap().startAdvertising() failed\r\n"); + return; + } + } + + void update_sensor_value() { + if (_connected) { + // Do blocking calls or whatever is necessary for sensor polling. + // In our case, we simply update the HRM measurement. + _hr_counter++; + + // 100 <= HRM bps <=175 + if (_hr_counter == 175) { + _hr_counter = 100; + } + + _hr_service.updateHeartRate(_hr_counter); + } + } + + void blink(void) { + _led1 = !_led1; + } + +private: + /* Event handler */ + + void onDisconnectionComplete(const ble::DisconnectionCompleteEvent&) { + _ble.gap().startAdvertising(ble::LEGACY_ADVERTISING_HANDLE); + _connected = false; + } + + virtual void onConnectionComplete(const ble::ConnectionCompleteEvent &event) { + if (event.getStatus() == BLE_ERROR_NONE) { + _connected = true; + } + } + +private: + BLE &_ble; + events::EventQueue &_event_queue; + DigitalOut _led1; + + bool _connected; + + UUID _hr_uuid; + + uint8_t _hr_counter; + HeartRateService _hr_service; + + 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); + + HeartrateDemo demo(ble, event_queue); + demo.start(); + + return 0; +} +