GY-63_MS5611/libraries/PulsePattern/PulsePattern.cpp
2017-07-16 16:01:09 +02:00

132 lines
3.1 KiB
C++

//
// FILE: PulsePattern.cpp
// AUTHOR: Rob dot Tillaart at gmail dot com
// VERSION: see PULSEPATTERN_LIB_VERSION in .h
// PURPOSE: PulsePattern library for Arduino
//
// HISTORY:
// 0.0.1 - 2012-11-23 initial version
// 0.0.2 - 2012-11-23 adapted a static PPO
// 0.0.3 - 2012-12-27 renamed to PulsePattern
// 0.0.4 - 2012-12-27 code stable(?) enough to publish
// 0.0.5 - 2012-12-27 code cleanup+comment
// 0.0.6 - 2015-04-18 completed the state machine
// 0.0.7 - 2017-07-16 refactor & review
//
// Released to the public domain
//
// TODO
// - fast function iso array to return the next period?
// more adaptive to e.g. sensor values. (investigate)
// - test PRE 1.0 backwards compatibility
// - move code to .h file so compiler can inline?
// - optimize timer code
// - adjust timing to more accurate values -> setTimer()
// - worker should be private - how???
// - test invalid array periods
// - start en stop index ipv size?
// - pulsepattern recorder
//
#include "PulsePattern.h"
#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
// 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(uint8_t pin, uint16_t * ar, uint8_t size,
uint8_t level, uint8_t prescaler)
{
_pin = pin;
pinMode(_pin, OUTPUT);
stop();
_ar = ar;
_size = size;
// TODO: run over the array to test invalid values?
// constrain them 10-4095?
_level = constrain(level, LOW, HIGH);
_prescaler = constrain(prescaler, PRESCALE_1, PRESCALE_1024);
_cnt = 0;
digitalWrite(_pin, _level);
_state = STOPPED;
}
void PulsePattern::start()
{
if (_size == 0) return; // no pattern
if (_state == RUNNING) return; // no restart
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;
// direct port faster
digitalWrite(_pin, _level);
// TODO: adjustment needed for code overhead when micros?;
// + 5.2 usec for digitalWrite
// + 3 usec for settimer call
OCR1A = (_ar[_cnt]) * (F_CPU/1000000L);
_cnt++;
if (_cnt >= _size) _cnt = 0; // repeat
}
// TIMER code based upon - http://www.gammon.com.au/forum/?id=11504
void PulsePattern::stopTimer()
{
TCCR1A = 0; // reset timer 1
TCCR1B = 0;
}
// TODO: can be optimized?
void PulsePattern::setTimer(const uint16_t cc) const
{
TCCR1A = 0;
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