mg811.hpp

/*
 * Author: Jon Trulson <jtrulson@ics.com>
 * Copyright (c) 2015 Intel Corporation.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#pragma once

#include <iostream>
#include <string>
#include <mraa/aio.hpp>
#include <mraa/gpio.hpp>

namespace upm {
  class MG811 {
  public:

    MG811(int pin, int dpin, float aref=5.0);

    ~MG811();

    float getReferenceVoltage();

    void setCalibration(float ppm400, float ppm1000);

    float volts();

    float ppm();

    bool thresholdReached();

  protected:
    mraa::Aio m_aio;
    mraa::Gpio m_gpio;

    // calibration values
    float m_zeroPointValue;
    float m_reactionValue;

    // ADC resolution
    int m_aRes;

  private:
    float m_aref;
  };
}