#include <Arduino.h>
#include <avr/io.h>
#include <avr/interrupt.h>


void delay() {
  TCCR1A = 0x00;
  TCCR1B = 0x00;

  // Set initial count (34286) so overflow happens after 2 seconds (prescaler 1024)
  TCNT1 = 34286;
  // TCNT1 = 0x85EE;
  TCCR1B |= (1 << CS02) | (1 << CS10);  // CS12 and CS10 set -> prescaler = 1024
  //while ((TIFR1 & (1 << TOV1)) == 0);
  //TCCR1B = 0x00;
  //TIFR1 |= (1 << TOV1);
  TIMSK1 |= (1 << TOIE1);
}

void setup() {
  DDRB = 0xFF;
  PORTB = 0x00;
  delay();
}
void loop() {
//  delay();  // Wait for 2 seconds
//  PORTB = ~PORTB;
}

ISR(TIMER1_OVF_vect)   // I misspelled the name of this timer overflow vector during the lecture.
{
  PORTB = ~PORTB;
  // TCNT1 = 0;
  // TIFR1 |= (1<< TOV1);
}