int period; // declare period as global variable

ISR(PCINT2_vect)     // interrupt service routine for pin change interrupt request 2
{ 
  if (PIND & 0b10000000){         // if pin 7 is high
    period = TCNT1*.0000625*1024; // convert clock ticks to milliseconds
    Serial.println(period);
  }else{                          // pin 7 is low
    TCNT1 = 0;                    // reset the timer to 0
  }
}

int main(void)
{
  // setup code that only runs once
  
  DDRD = 0b00000000;   // set pin 7 as input
  PORTD = 0b10000000;  // enable internal pullup on pin 7
  
  PCICR = 0b00000100;  // enable pin change interrupt on pin 7
  PCMSK2 = 0b10000000; 
  sei();               // enable interrupts
  
  TCCR1A = 0b00000000; // set timer 1 to normal mode
  TCCR1B = 0b00000101; // and set prescaler to 1024
  
  Serial.begin(9600);  // initialize serial

  while(1){
    // code that loops forever
      
  } 
}



/*
TCNT1 = 0;
owerflow = 0;

dummy = dummy + 65536*owerflov

unsigned long dummy;

dummy = TCNT1;





/ Declare your global variables here   
uint8_t Overflow;
uint32_t Dummy;
uint8_t Inmpulse;


// Timer 1 overflow interrupt service routine  ----------------------------------

interrupt [TIM1_OVF] void timer1_ovf_isr(void)
{
Overflow = Overflow + 1;
}

// Timer 1 input capture interrupt service routine ------------------------------

interrupt [TIM1_CAPT] void timer1_capt_isr(void)

{
  Dummy = TCNT1;
  Dummy = Dummy + 65536 * Overflow; 
  Dummy = Dummy * 0.000000125;
  Impulse = 60 / Dummy;
}

ISR(TIMER1_COMPA_vect)    
ISR(TIMER1_OVF_vect) 





*/