File content as of revision 2:45ed62566694:

/*  BME280 BLE sensor -- main.cpp
*
*   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.
*
*   Copyright 2019 Fedor Chervyakov
*/

#include "mbed.h"

#include <stdio.h>

#include "events/EventQueue.h"
#include "platform/Callback.h"
#include "platform/NonCopyable.h"

#include "ble/BLE.h"
#include "ble/Gap.h"
#include "ble/GattClient.h"
#include "ble/GattServer.h"
#include "ble/GapAdvertisingParams.h"
#include "ble/GapAdvertisingData.h"
#include "ble/FunctionPointerWithContext.h"
#include "ble/services/EnvironmentalService.h"

#include "bme280_wrapper.h"
#include "stats_report.h"


using mbed::callback;

Thread t;
Thread stats_report_thread;

AnalogIn lm35_input(A0); /* ADC input pin connected to Vout of LM35 */


#define SLEEP_TIME 5 /* loop delay in seconds */
#define V_SUPPLY 3.3 /* System voltage */
#define K_LM35 0.01  /* Linear coefficient in transfer function of LM35: Vout = K [V/degC] * T [degC] */
#define BLE_DEVICE_NAME "BME280 sensor"
#define UPDATE_RATE 5000 /* ms */


class BME280BLE : private mbed::NonCopyable<BME280BLE>, public ble::Gap::EventHandler {
public:
    
    BME280BLE(events::EventQueue &event_queue, BLE &ble_interface) :
        _ble_interface(ble_interface),
        _gap(_ble_interface.gap()),
        _event_queue(event_queue),
        _post_init_cb(),
        _bme280(BME280(I2C_SDA, I2C_SCL)),
        _env_service(NULL),
        _env_service_uuid(GattService::UUID_ENVIRONMENTAL_SERVICE)
    {
    }

    ~BME280BLE() {
        stop();
    }

    void on_init(mbed::Callback<void(BLE&, events::EventQueue&)> cb) {
        _post_init_cb = cb;
    }

    bool start() {
        
        printf("BLE process has started. \r\n");
        
        if (_ble_interface.hasInitialized()) {
            printf("Error: the BLE instance has already been initialized! \r\n");
            return false;
        }

        /* Set Gap EventHandler to this class */
        _gap.setEventHandler(this);

        _ble_interface.onEventsToProcess(
            makeFunctionPointer(this, &BME280BLE::schedule_ble_events)
        );

        /* Initialize BLE interface */
        ble_error_t error = _ble_interface.init(this, &BME280BLE::when_init_complete);
        if (error) {
            printf("Error: %u returned by BLE::init.\r\n", error);
            return false;
        }
        
        _event_queue.call_every(UPDATE_RATE, this, &BME280BLE::update_measurements);

        return true;
    }

    void stop() {
        if (_ble_interface.hasInitialized()) {
            _ble_interface.shutdown();
            printf("BLE process stopped.\r\n");
        }

    }

private:
    
    void schedule_ble_events(BLE::OnEventsToProcessCallbackContext *event) {
        _event_queue.call(mbed::callback(&event->ble, &BLE::processEvents));
    }

    void when_init_complete(BLE::InitializationCompleteCallbackContext *event) {
        
        if (event->error) {
            printf("Error %u during the initialization.\r\n", event->error);
        }
        printf("BLE instance initialized.\r\n");

        /* Setup environmental service */
        _env_service = new EnvironmentalService(_ble_interface);

        if (!set_advertising_parameters()) {
            return;
        }

        if (!set_advertising_data()) {
            return;
        }

        if (!start_advertising()){
            return;
        }

        
        if (_post_init_cb) {
            _post_init_cb(_ble_interface, _event_queue);
        }
    }

    bool set_advertising_parameters() {
        ble_error_t error = _gap.setAdvertisingParameters(
            ble::LEGACY_ADVERTISING_HANDLE,
            ble::AdvertisingParameters(
                ble::advertising_type_t::CONNECTABLE_UNDIRECTED,
                ble::adv_interval_t(ble::millisecond_t(1000))
            )
        );

        if (error) {
            printf("Gap::setAdvertisingParameters() failed with error %d", error);
            return false;
        }

        return true;
    }

    bool set_advertising_data() {
        /* Use the simple builder to construct the payload; it fails at runtime
         * if there is not enough space left in the buffer */
        ble_error_t error = _gap.setAdvertisingPayload(
            ble::LEGACY_ADVERTISING_HANDLE,
            ble::AdvertisingDataSimpleBuilder<ble::LEGACY_ADVERTISING_MAX_SIZE>()
                .setFlags()
                .setLocalServiceList(mbed::make_Span(&_env_service_uuid, 1))
                .setName(BLE_DEVICE_NAME)
                .getAdvertisingData()
        );

        if (error) {
            printf("Gap::setAdvertisingPayload() failed with error %d", error);
            return false;
        }

        return true;
    }

    bool start_advertising() {
        /* Start advertising the set */
        ble_error_t error = _gap.startAdvertising(ble::LEGACY_ADVERTISING_HANDLE);

        if (error) {
            printf("Error %u during gap.startAdvertising.\r\n", error);
            return false;
        } else {
            printf("Advertising started.\r\n");
            return true;
        }
    }

private:
    /* Gap::EventHandler */

    virtual void onConnectionComplete(const ble::ConnectionCompleteEvent &event) {
        printf("Connected.\r\n");
    }

    virtual void onDisconnectionComplete(const ble::DisconnectionCompleteEvent &event) {
        printf("Disconnected.\r\n");
        start_advertising();
    }

private:
    /* EnvironmentalService */

    void update_measurements() {

        struct bme280_data *comp_data;
        EnvironmentalService::HumidityType_t humidity; // uint16_t
        EnvironmentalService::PressureType_t pressure; // uint32_t
        float temperature; // int16_t

        _bme280.force_measurement();

        comp_data = &_bme280.comp_data;

        temperature = comp_data->temperature;
        humidity = comp_data->humidity;
        pressure = comp_data->pressure;

        _env_service->updateTemperature(temperature);
        _env_service->updatePressure(pressure);
        _env_service->updateHumidity(humidity);
            
    }

private:
    BLE &_ble_interface;
    Gap &_gap;
    EnvironmentalService *_env_service;
    UUID _env_service_uuid;

    events::EventQueue &_event_queue;
    mbed::Callback<void(BLE&, events::EventQueue&)> _post_init_cb;

    BME280 _bme280;

};



void print_sensor_data(struct bme280_data *comp_data)
{
    float temp, press, hum;

    temp = comp_data->temperature;
    press = 0.01 * comp_data->pressure;
    hum = comp_data->humidity;

    printf("BME280 %0.2lf deg C, %0.2lf hPa, %0.2lf%%\n", temp, press, hum);
}


float lm35_temperature() {
    float temperature;
    
    temperature = lm35_input.read() * V_SUPPLY / (K_LM35 * (1+10/4.7)) ;

    return temperature;
}


void print_stats() {
    SystemReport sys_report(SLEEP_TIME * 1000);

    while (true) {
        sys_report.report_state();
        wait(SLEEP_TIME);
    }
}



// main() runs in its own thread in the OS
int main()
{
    events::EventQueue event_queue; /* Event queue */
    BLE &ble_interface = BLE::Instance(); /* Bluetooth interface */
    BME280BLE ble_process(event_queue, ble_interface);
    
    ble_process.start();

    t.start(mbed::callback(&event_queue, &EventQueue::dispatch_forever));
    stats_report_thread.start(print_stats);

    while (true) {
        printf("LM35 %.2f deg C; ", lm35_temperature());

        wait(SLEEP_TIME);
    }

}