unsigned int i;
void setup() {
  DDRC |= 1<<6;
}

void loop() {
  for(i=0; i<7; i++)
  {
    PORTC |= 1<<6;
    delay(50*i);
    PORTC &= ~(1<<6);
    delay(700-50*i);
  }
  delay(1300);
}