#include <avr/interrupt.h>
int count1=0;
ISR(TIMER1_COMPA_vect)
{ 
  TCNT1=0;
  count1++;
  Serial.println(count1);
  
}
ISR(TIMER1_OVF_vect)
{ 
 digitalWrite(4, HIGH);
   OCR1A+=62.5;
  digitalWrite(4,LOW);
  
}

void setup() {
    pinMode(4, OUTPUT);
    pinMode(13, OUTPUT);
  // put your setup code here, to run once:
    TCCR1B=0;
    TCCR1A=0;
    TCCR1B|=B00000100;
   // OCR1A=62.5;
    TIMSK1|=B00000011;
    Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
    
    task1();

}

void task1()
{
  if(count1==10)
  {
    //TIMSK1|=B00000001;
  }
  digitalWrite(13, HIGH);
   OCR1A+=62.5;
  digitalWrite(13,LOW);
  OCR1A+=62.5;

}