volatile int toggleCount = 0;  // Counter to track the number of toggles

void setup() {
  // Initialize Serial communication at 9600 baud rate
  Serial.begin(9600);
  
  // Setup PORTF0 as output
  volatile char *dirf = (volatile char *) 0x30;  // DDRF register for direction
  volatile char *outf = (volatile char *) 0x31;  // PORTF register for output
  *dirf |= 0x01;  // Set F0 as output (bit 0 of PORTF)

  // Configure Timer1
  TCCR1A = 0;                  // Normal operation mode
 TCCR1B = (1 << WGM12);      // CTC mode (Clear Timer on Compare Match)
  TCCR1B |= (1 << CS12); 

       // Set prescaler to 256 (16 MHz / 256)
  OCR1A = 65000- 1;          // Set compare match value for 1 Hz toggle (with 256 prescaler)
  
  TIMSK1 = (1 << OCIE1A);     // Enable Timer1 compare interrupt

  sei();  // Enable global interrupts
}

ISR(TIMER1_COMPA_vect) {
  volatile char *outf = (volatile char *) 0x31;  // PORTF register
  *outf ^= 0x01;  // Toggle F0 (connected LED)

  toggleCount++;  // Increment toggle count
  Serial.print("Toggle Count: ");
  Serial.println(toggleCount);  // Print count to serial

  // Stop the timer after 10 toggles
  if (toggleCount >= 10) {
    TCCR1B &= ~(1 << CS12);  // Stop Timer1 (clear prescaler bits)
 
    Serial.println("Timer stopped after 10 toggles.");
  }
}

void loop() {
  // Nothing needed here; everything is handled in the interrupt
}