#pragma once
//
//    FILE: HX711.h
//  AUTHOR: Rob Tillaart
// VERSION: 0.3.4
// PURPOSE: Library for load cells for Arduino
//     URL: https://github.com/RobTillaart/HX711
//
// HISTORY: see CHANGELOG.md
//
//  NOTES
//  Superset of interface of HX711 class of Bogde
//  float instead of long as float has 23 bits mantissa.


#include "Arduino.h"

#define HX711_LIB_VERSION               (F("0.3.4"))


const uint8_t HX711_AVERAGE_MODE = 0x00;
//  in median mode only between 3 and 15 samples are allowed.
const uint8_t HX711_MEDIAN_MODE  = 0x01;
//  medavg = average of the middle "half" of sorted elements
//  in medavg mode only between 3 and 15 samples are allowed.
const uint8_t HX711_MEDAVG_MODE  = 0x02;
//  runavg = running average
const uint8_t HX711_RUNAVG_MODE  = 0x03;
//  causes read() to be called only once!
const uint8_t HX711_RAW_MODE     = 0x04;


//  supported values for set_gain()
const uint8_t HX711_CHANNEL_A_GAIN_128 = 128;  // default
const uint8_t HX711_CHANNEL_A_GAIN_64 = 64;
const uint8_t HX711_CHANNEL_B_GAIN_32 = 32;


class HX711
{
public:
  HX711();
  ~HX711();

  //  fixed gain 128 for now
  void     begin(uint8_t dataPin, uint8_t clockPin);

  void     reset();

  //  checks if load cell is ready to read.
  bool     is_ready();

  //  wait until ready,
  //  check every ms
  void     wait_ready(uint32_t ms = 0);
  //  max # retries
  bool     wait_ready_retry(uint8_t retries = 3, uint32_t ms = 0);
  //  max timeout
  bool     wait_ready_timeout(uint32_t timeout = 1000, uint32_t ms = 0);

  //  raw read
  float    read();

  //  get average of multiple raw reads
  //  times = 1 or more
  float    read_average(uint8_t times = 10);

  //  get median of multiple raw reads
  //  times = 3..15 - odd numbers preferred
  float    read_median(uint8_t times = 7);

  //  get average of "middle half" of multiple raw reads.
  //  times = 3..15 - odd numbers preferred
  float    read_medavg(uint8_t times = 7);

  //  get running average over times measurements.
  //  the weight alpha can be set to any value between 0 and 1
  //  times = 1 or more.
  float    read_runavg(uint8_t times = 7, float alpha = 0.5);


  //  get set mode for get_value() and indirect get_units().
  //  in median and medavg mode only 3..15 samples are allowed.
  void     set_raw_mode()     { _mode = HX711_RAW_MODE; };
  void     set_average_mode() { _mode = HX711_AVERAGE_MODE; };
  void     set_median_mode()  { _mode = HX711_MEDIAN_MODE; };
  void     set_medavg_mode()  { _mode = HX711_MEDAVG_MODE; };
  //  set_run_avg will use a default alpha of 0.5.
  void     set_runavg_mode()  { _mode = HX711_RUNAVG_MODE; };
  uint8_t  get_mode()         { return _mode; };

  //  corrected for offset.
  //  in HX711_RAW_MODE the parameter times will be ignored.
  float    get_value(uint8_t times = 1);
  //  converted to proper units.
  //  in HX711_RAW_MODE the parameter times will be ignored.
  float    get_units(uint8_t times = 1);


  //  TARE
  //  call tare to calibrate zero
  void     tare(uint8_t times = 10)     { _offset = read_average(times); };
  float    get_tare()                   { return -_offset * _scale; };
  bool     tare_set()                   { return _offset != 0; };


  //  CORE "CONSTANTS" -> read datasheet
  //  CHANNEL      GAIN   notes
  //  -------------------------------------
  //     A         128    default, tested
  //     A          64
  //     B          32

  //  returns true  ==>  parameter gain is valid
  //  returns false ==>  parameter gain is invalid ==> no change.
  //  note that changing gain/channel takes up to 400 ms (page 3)
  //  if forced == true, the gain will be forced set 
  //  even it is already the right value
  bool     set_gain(uint8_t gain = HX711_CHANNEL_A_GAIN_128, bool forced = false);
  uint8_t  get_gain();


  //  SCALE > 0
  void     set_scale(float scale = 1.0) { _scale = 1.0 / scale; };
  float    get_scale()                  { return 1.0 / _scale; };

  //  OFFSET > 0
  void     set_offset(long offset = 0)  { _offset = offset; };
  long     get_offset()                 { return _offset; };


  //  CALIBRATION
  //  clear the scale
  //  call tare() to set the zero offset
  //  put a known weight on the scale
  //  call calibrate_scale(weight)
  //  scale is calculated.
  void     calibrate_scale(uint16_t weight, uint8_t times = 10);
  //  obsolete typo but just do not want to break interface yet
  void     callibrate_scale(uint16_t weight, uint8_t times = 10);


  //  POWER MANAGEMENT
  void     power_down();
  void     power_up();


  //  TIME OF LAST READ
  uint32_t last_read()                  { return _lastRead; };


  //  PRICING  (idem calories?)
  float    get_price(uint8_t times = 1) { return get_units(times) * _price; };
  void     set_unit_price(float price = 1.0) { _price = price; };
  float    get_unit_price() { return _price; };


private:
  uint8_t  _dataPin;
  uint8_t  _clockPin;

  uint8_t  _gain     = 128;     // default channel A
  long     _offset   = 0;
  float    _scale    = 1;
  uint32_t _lastRead = 0;
  float    _price    = 0;
  uint8_t  _mode     = 0;

  void     _insertSort(float * array, uint8_t size);
  uint8_t  _shiftIn();
};


//  -- END OF FILE --