Uart.h

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/****
 * Uart.h
 *
 * Copyright 2021 mikee47 <mike@sillyhouse.net>
 *
 * This file is part of the Sming-MHZ19 Library
 *
 * This library is free software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation, version 3 or later.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this library.
 * If not, see <https://www.gnu.org/licenses/>.
 *
 ****/

#pragma once

#include <HardwareSerial.h>
#include <SimpleTimer.h>
#include "common.h"

namespace MHZ19
{
enum Command {
    CMD_GasConcentration = 0x86,    
    CMD_CalibrateZeroPoint = 0x87,  
    CMD_CalibrateSpanPoint = 0x88,  
    CMD_SelfCalbrationOnOff = 0x79, 
    CMD_SetDetectionRange = 0x99,   
};

struct Request {
    uint8_t start;
    uint8_t sensor;
    uint8_t command;
    uint8_t data[5];
    uint8_t checksum;
};

struct Response {
    uint8_t start;
    uint8_t command;
    uint8_t data[6];
    uint8_t checksum;
};

enum class Error {
    success,
    incompleteResponse,
    invalidResponse,
    timeout,
};

struct Measurement {
    Error error;
    uint8_t status;
    uint16_t co2_ppm;
    int16_t temperature;
};

using MeasurementCallback = Delegate<void(Measurement& m)>;

class Uart
{
public:
    Uart(HardwareSerial& serial) : serial(serial)
    {
    }

    void setSensorNumber(uint8_t num)
    {
        sensorNumber = num;
    }

    uint8_t getSensorNumber() const
    {
        return sensorNumber;
    }

    void setAutoCalibration(bool enable);

    void calibrateZero();

    void calibrateSpan(uint16_t ppm);

    void setDetectionRange(DetectionRange range);

    bool getMeasurement(MeasurementCallback callback);

protected:
    void sendRequest(Request& request);

private:
    void onData();
    void processResponse(Response& response);
    void returnMeasurement(Measurement& m);

    HardwareSerial& serial;
    uint8_t sensorNumber{0x01}; 
    SimpleTimer timer;
    MeasurementCallback callback;
};

} // namespace MHZ19

String toString(MHZ19::Error error);