//
//    FILE: AnalogPin.cpp
//  AUTHOR: Rob Tillaart
// VERSION: 0.2.4
//    DATE: 2013-09-09
// PURPOSE: wrapper for analogRead with smoothing and noise filtering
//
// HISTORY:
// 0.1.00 - 2013-09-09  initial version
// 0.1.01 - 2013-11-09  added some comments
// 0.1.02 - 2014-10-05  changed signatures datatypes
// 0.1.03 - 2014-12-07  some refactor
// 0.1.04 - 2015-03-06  refactor smaller footprint
// 0.2.00 - 2015-05-14  added prescale support
// 0.2.01 - 2015-12-19  breaking interface; big refactor;
// 0.2.2    2020-03-25  refactor AVR specific code; bugfix
// 0.2.3    2020-05-27  update library.json
// 0.2.4    2020-12-10  add Arduino-ci
//
// Released to the public domain
//

#include "AnalogPin.h"

AnalogPin::AnalogPin(const uint8_t pin)
{
  _pin      = pin;
  _prescale = 7;
  _alpha    = 0;
  _noise    = 0;
  rawRead();
  _prevValue = _value;
}

int AnalogPin::read(const bool twice)
{
  if (twice) rawRead();
  rawRead();
  if ( (_noise == 0) || (((_value - _prevValue) & 0x7FFF) > _noise) )
  {
    _prevValue = _value;
  }
  return _prevValue;
}

int AnalogPin::readSmoothed()
{
  rawRead();
  if (_alpha > 0)
  {
    _value = _value + (_alpha * (_prevValue - _value)) / 32;
  }
  _prevValue = _value;
  return _value;
}

void AnalogPin::rawRead()
{
#if defined(ARDUINO_ARCH_AVR)
  // remember old register value
  uint8_t ADCSRA_TMP = ADCSRA;
  ADCSRA = (ADCSRA | 0x07) & (0xF8 | _prescale);
#elif defined(ARDUINO_ARCH_SAM)

#else

#endif

  _value = analogRead(_pin);

#if defined(ARDUINO_ARCH_AVR)
  // restore register
  ADCSRA = ADCSRA_TMP;
#elif defined(ARDUINO_ARCH_SAM)

#else

#endif
}

// -- END OF FILE --