//
//    FILE: PulsePattern.cpp
//  AUTHOR: Rob Tillaart
// VERSION: 0.1.7
//    DATE: 2012-11-23
// PURPOSE: Arduino Library to generate repeating pulse patterns


#include "PulsePattern.h"


//  Predefined generator (singleton)
PulsePattern PPGenerator;


ISR(TIMER1_COMPA_vect)
{
  PPGenerator.worker();
}


PulsePattern::PulsePattern()
{
  _size = 0;
  _state = NOTINIT;
  _ar = NULL;
  _cnt = 0;
  _level = LOW;
  _prescaler = 0;
  _pin = 0;
}


void PulsePattern::init(const uint8_t pin, const uint16_t * ar, const uint8_t size,
const uint8_t level, const uint8_t prescaler)
{
  _pin = pin;
  pinMode(_pin, OUTPUT);
  stop();

  _ar = (uint16_t *) ar;
  _size = size;
  _level = level ? LOW : HIGH;
  _prescaler = constrain(prescaler, PRESCALE_1, PRESCALE_1024);
  _cnt = 0;

  digitalWrite(_pin, _level);
  _state = STOPPED;

  //  fast low level AVR ports
  uint8_t _pinport = digitalPinToPort(_pin);
  _pinout = portOutputRegister(_pinport);
  _pinbit = digitalPinToBitMask(_pin);
}


void PulsePattern::start(uint32_t times)
{
  if (_state == RUNNING) return;  //  no restart
  _cnt   = 0;                     //  start from begin
  _times = times;
  cont();
}


void PulsePattern::cont()
{
  if (_state == RUNNING) return;  //  no continue
  if (_size == 0) return;         //  no pattern
  setTimer(1);                    //  start asap
  _state = RUNNING;
}


void PulsePattern::stop()
{
  stopTimer();
  _state = STOPPED;
  _level = LOW;
  digitalWrite(_pin, _level);
}


void PulsePattern::worker()
{
  if (_state != RUNNING) return;
  //  set next period & flip signal
  _level = !_level;
  //  digitalWrite(_pin, _level);
  //  direct port much faster
  if (_level == 0) *_pinout &= ~_pinbit;
  else *_pinout |= _pinbit;

  if (_factor != 4096)
  {
    OCR1A = _ar[_cnt] * _factor * (F_CPU/1000000UL) / 4096;
  }
  else
  {
    OCR1A = _ar[_cnt] * (F_CPU/1000000UL);
  }
  _cnt++;
  if (_cnt >= _size)
  {
    _cnt = 0;  // reset pattern
    switch(_times)
    {
      case PP_CONTINUOUS:
        break;
      case 1:
        _times--;
      case 0:
        stop();
        break;
      default:
        _times--;
        break;
    }
  }
}


//  TIMER code based upon - http://www.gammon.com.au/forum/?id=11504
void PulsePattern::stopTimer()
{
  TCCR1A = 0;        //  reset timer 1
  TCCR1B = 0;
}


void PulsePattern::setTimer(const uint16_t cc) const
{
  TCCR1A = 0;               //  stop timer first
  TCCR1B = 0;
  TCNT1 = 0;                //  reset counter
  OCR1A = cc * 16;          //  compare A register value;
  //  * 16 makes max period 4095
  //  min period 12?

  //  4: CTC mode, top = OCR1A
  TCCR1A = _BV (COM1A1);    //  clear on compare
  TCCR1B = _BV (WGM12) | _prescaler;
  TIFR1 |= _BV (OCF1A);     //  clear interrupt flag
  TIMSK1 = _BV (OCIE1A);    //  interrupt on Compare A Match
}


//  -- END OF FILE --