// Arduino clock frequency is 16 MHz

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

unsigned int n_compare_matchs = 0;

ISR(TIMER2_COMPA_vect)
{
    // TASK: Use n_compare_matchs to toggle D12 on each timer interrupt
    // and Toggle D13 at 1 sec interval.

    // Toggle D12 (PB4) on each interrupt
    PORTB ^= (1 << PB4);

    // Increment the compare match counter
    n_compare_matchs++;

    // Toggle D13 (PB5) after 125 interrupts
    if (n_compare_matchs >= 125)
    {
        PORTB ^= (1 << PB5);  // Toggle D13
        n_compare_matchs = 0; // Reset the counter
    }
}

int main()
{
    // TASK: set the prescaler for Timer2 to 1024
    TCCR2B = (1 << CS22) | (1 << CS21) | (1 << CS20); // Prescaler 1024

    // TASK: set Wave Generation mode to CTC (Clear Timer on Compare Match)
    TCCR2A = (1 << WGM21);

    // TASK: Set upper limit for CTC with OCR2A (remember: ticks start from 0)
    OCR2A = 124; // Compare match value for 125 counts

    // TASK: Enable Timer2 interrupt on compare match
    TIMSK2 = (1 << OCIE2A);

    // TASK: Set pin modes for D13 and D12
    DDRB |= (1 << PB5) | (1 << PB4); // Set PB5 (D13) and PB4 (D12) as outputs

    // TASK: Enable Interrupts
    sei(); // Enable global interrupts

    // Infinite loop
    while (1)
        ;
}