/* Title: interrupt.c
 * Author: Corey Crawford, [email protected]
 * Description: Testing interrupts on tiny85
 * Created: Dec 17, 2023
 * Edited: Dec 18, 2023
 *
 * TODO : Assess and mitigate button bounce
 *
 */

// Import device headers and init program functions
#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <TinyDebug.h>


void init();

// Main function
int main() {

  init();
  Debug.begin();

  // Enters blink loop
  for(;;){
    // Toggle pin PB0 and wait
    PORTB ^= 0x01;
    Debug.print("\nloop");
    _delay_ms(1000);    
  }

  return(1);
}


// Initialization of output pins and ISR
void init(){
  GIMSK &= 0b00000000; // Disables interrupts
  DDRB  |= 0b00000011; // Sets Ports PB0 and PB1 as outputs
  SREG  |= 0b10000000; // Sets global interrupt flag
  MCUCR |= 0b00000010; // Sets ext interrupt for falling edge
  GIMSK |= 0b01000000; // Enables interrupts
}


// Interrupt Service Routine
ISR(INT0_vect){
  // Toggles output of pin PB1
  PORTB ^= 0b00000010; 
  GIFR  |= 0b01000000; // Clears interrupt flag
  Debug.print(" interrupted!");
}