volatile uint8_t timer0_count = 0;
volatile uint8_t timer2_count = 0;

void setupTimer0() {
  noInterrupts();
  // Clear registers
  TCCR0A = 0;
  TCCR0B = 0;
  TCNT0 = 0;
  OCR0A = 155; // 1 Hz
  TCCR0A |= (1 << WGM01); // CTC
  TCCR0B |= (1 << CS02) | (1 << CS00);
  TIMSK0 |= (1 << OCIE0A); // Output Compare Match A Interrupt Enable
  interrupts();
}

void setupTimer1() {
  noInterrupts();
  // Clear registers
  TCCR1A = 0;
  TCCR1B = 0;
  TCNT1 = 0;
  OCR1A = 7812; // 2 Hz
  TCCR1B |= (1 << WGM12); // CTC
  TCCR1B |= (1 << CS12) | (1 << CS10);
  TIMSK1 |= (1 << OCIE1A); // Output Compare Match A Interrupt Enable
  interrupts();
}

void setupTimer2() {
  noInterrupts();
  // Clear registers
  TCCR2A = 0;
  TCCR2B = 0;
  TCNT2 = 0;
  OCR2A = 155; // 5 Hz
  TCCR2B |= (1 << WGM21); // CTC
  TCCR2B |= (1 << CS22) | (1 << CS21) | (1 << CS20);
  TIMSK2 |= (1 << OCIE2A); // Output Compare Match A Interrupt Enable
  interrupts();
}

void setupTimer3() {
  noInterrupts();
  // Clear registers
  TCCR3A = 0;
  TCCR3B = 0;
  TCNT3 = 0;
  OCR3A = 1562; // 10 Hz
  TCCR3B |= (1 << WGM32); // CTC
  TCCR3B |= (1 << CS32) | (1 << CS30);
  TIMSK3 |= (1 << OCIE3A); // Output Compare Match A Interrupt Enable
  interrupts();
}

void setup() {
  // put your setup code here, to run once:
  DDRC = 0XFF;
  PORTC = 0x00;
  setupTimer0();
  setupTimer1();
  setupTimer2();
  setupTimer3();
}

void loop() {
  // put your main code here, to run repeatedly:

}

// Timer0 ISR - 1 Hz (100Hz base divided by 100)
ISR(TIMER0_COMPA_vect) {
  timer0_count++;
  if (timer0_count >= 100) { // Divide by 100 to get 1 Hz
    timer0_count = 0;
    PORTC ^= (1 << PC0) | (1 << PC1); // Toggle pins PC0 and PC1
  }
}

// Timer1 ISR - 2 Hz
ISR(TIMER1_COMPA_vect) {
  PORTC ^= (1 << PC2) | (1 << PC3); // Toggle pins PC2 and PC3

}

ISR(TIMER2_COMPA_vect) {
  timer2_count++;
  if (timer2_count >= 20) { // Divide by 20 to get 5 Hz
    timer2_count = 0;
    PORTC ^= (1 << PC4) | (1 << PC5); // Toggle pins PC4 and PC5
  }
}

// Timer3 ISR - 10 Hz
ISR(TIMER3_COMPA_vect) {
  PORTC ^= (1 << PC6) | (1 << PC7); // Toggle pins PC6 and PC7
}