dfrec.h

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/*
 * 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 <stdint.h>
#include "upm.h"
#include "mraa/aio.h"

#include "ds18b20.h"

#ifdef __cplusplus
extern "C" {
#endif

  typedef struct _dfrec_context {
    mraa_aio_context    aio;

    // ds18b20 context (for temperature measurement
    ds18b20_context     ds18b20;
    unsigned int        device_idx;

    // analog ADC resolution
    float               a_res;

    // analog reference voltage
    float               a_ref;

    // for external offset and scaling of the results
    float               offset;
    float               scale;

    // volts
    float               volts;

    // normalized ADC
    float               normalized;

    // the EC value
    float               ec;

    // EC threshold min/max (mV)
    float               thres_min; // 150
    float               thres_max; // 3300

    // the temperature read from the ds18b29
    float               temperature;

    // thresholds, scales, and offsets taken from the DFRobot code
    float               thres_1;   // 448
    float               scale_1;   // 6.84
    float               offset_1;  // -64.32

    float               thres_2;   // 1457
    float               scale_2;   // 6.98
    float               offset_2;  // -127.0

    float               scale_3;   // 5.3
    float               offset_3;  // +2278.0
  } *dfrec_context;

  dfrec_context dfrec_init(unsigned int apin, unsigned int uart_ow,
                           unsigned int device_idx,
                           float a_ref);

  void dfrec_close(dfrec_context dev);

  upm_result_t dfrec_update(const dfrec_context dev);

  void dfrec_set_offset(const dfrec_context dev, float offset);

  void dfrec_set_scale(const dfrec_context dev, float scale);

  float dfrec_get_ec(const dfrec_context dev);

  float dfrec_get_volts(const dfrec_context dev);

  float dfrec_get_temperature(const dfrec_context dev);

  float dfrec_get_normalized(const dfrec_context dev);

  void dfrec_set_threshold_min_max(const dfrec_context dev, float min,
                                   float max);

  void dfrec_set_threshold_1(const dfrec_context dev, float thres,
                             float scale, float offset);

  void dfrec_set_threshold_2(const dfrec_context dev, float thres,
                             float scale, float offset);

  void dfrec_set_threshold_3(const dfrec_context dev, float scale,
                             float offset);


#ifdef __cplusplus
}
#endif