tex00.hpp

/*
 * Author: Jon Trulson <jtrulson@ics.com>
 * Copyright (c) 2016 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 <string>
#include <iostream>
#include <vector>

#include <mraa/aio.hpp>

#define TEX00_DEFAULT_AREF 5.0

namespace upm {
  class TEX00 {
  public:

    typedef enum {
      STYPE_THERMISTOR_TED               = 0, // 10k type 2
      STYPE_THERMISTOR_TEB,                   // 100 Ohm
      STYPE_THERMISTOR_TEC,                   // 1000 Ohm
      STYPE_THERMISTOR_TEI,                   // 1000 Ohm
      STYPE_THERMISTOR_TEE,                   // 2.2k
      STYPE_THERMISTOR_TEF,                   // 3k
      STYPE_THERMISTOR_TEH,                   // 10k type 3
      STYPE_THERMISTOR_TEJ,                   // 10k Dale
      STYPE_THERMISTOR_TES,                   // 10k 3A221
      STYPE_THERMISTOR_TER,                   // 10k "G" US
      STYPE_THERMISTOR_TEM,                   // 20k NTC
      STYPE_THERMISTOR_TEU,                   // 20k "D"
      STYPE_THERMISTOR_TET                    // 100k
    } SENSOR_TYPES_T;

    TEX00(int tPin, float balanceResistor, SENSOR_TYPES_T stype,
          float aref=TEX00_DEFAULT_AREF);

    ~TEX00();

    void update();

    float getTemperature(bool fahrenheit=false);

    float getTemperatureRangeMin();

    float getTemperatureRangeMax();

    bool isOutOfRange()
    {
      return m_outOfRange;
    }

  protected:
    mraa::Aio m_aioTemp;

    // compute the temperature based on the resistance of the thermistor
    float thermistor(float ohms);

  private:
    float m_aref;
    int m_aResTemp;

    // in Celsius
    float m_temperature;
    // temp reading out of range
    bool m_outOfRange;

    // resistance of the other half of our voltage divider
    float m_balanceResistor;

    int average(int samples);

    // Negative Temperature Coefficient (NTC) or Positive Temperature
    // Coefficient (PTC)
    bool m_isNTC;

    // This may generate a SWIG warning.  It can be safely ignored
    // since this structure is never exposed outside the class.
    struct tempEntry
    {
      tempEntry(float o, float t) : ohms(o), temp(t) {};
      
      float ohms;
      float temp; // in C
    };

    // ohms/temperature table store
    std::vector<tempEntry> m_tempVector;

    // table temperature init functions
    void initThermistorTED();
    void initThermistorTEB();
    void initThermistorTEC();
    void initThermistorTEI();
    void initThermistorTEE();
    void initThermistorTEF();
    void initThermistorTEH();
    void initThermistorTEJ();
    void initThermistorTES();
    void initThermistorTER();
    void initThermistorTEM();
    void initThermistorTEU();
    void initThermistorTET();
  };
}