beatdetect.cpp

/*
 * Copyright Ben XO https://github.com/ben-xo All rights reserved.
 */

#if 0 // disabled

#include <Arduino.h>
#include "config.h"
#include "beatdetect.h"

void setup_beatdetect() {
    DDRD &= ~(1 << DDD2);     // Clear the PD2 pin
    DDRD &= ~(1 << DDD3);     // Clear the PD3 pin

//    PORTD |= (1 << PORTD2);    // turn On the Pull-up
//    PORTD |= (1 << PORTD3);    // turn On the Pull-up

    EICRA |= (1 << ISC10);    // set INT1 to trigger on ANY logic change
    EICRA |= (1 << ISC00);    // set INT1 to trigger on ANY logic change
    EIMSK |= (1 << INT0);     // Turns on INT0  
    EIMSK |= (1 << INT1);     // Turns on INT1 
}

ISR (INT1_vect, ISR_ALIASOF(INT0_vect));
ISR (INT0_vect, ISR_NAKED)
{
    /* interrupt code here */
// beats_from_interrupt = PIND & ((1 << BEAT_PIN_1) | (1 << BEAT_PIN_2)); // read once - port is volatile

  asm volatile( "push    r16                              \n\t");
  asm volatile( "in      r16, __SREG__                    \n\t");
  asm volatile( "push    r16                              \n\t");

  asm volatile( "in      r16, %0  ;                       \n\t" :: "I" (_SFR_IO_ADDR(PIND)));
  asm volatile( "andi    r16, %0  ;                       \n\t" :: "I" ((1 << BEAT_PIN_1) | (1 << BEAT_PIN_2)));
  asm volatile( "sts     %0, r16  ; beats_from_interrupt  \n\t" :: "X" ((uint8_t)_SFR_MEM_ADDR(beats_from_interrupt)));
         
  asm volatile( "pop     r16                              \n\t");
  asm volatile( "out     __SREG__, r16                    \n\t");
  asm volatile( "pop     r16                              \n\t");
  asm volatile( "reti                                     \n\t");
}

#endif