void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(115200);
 
  TCCR1A = 0;
  TCCR1B = bit(CS10);
  TCNT1 = 0;
  for(int i=0; i<1000; i++){
    // nothing
  }
  unsigned int cycles = TCNT1;
  Serial.print("Cycles: ");
  Serial.println(cycles - 1);
  Serial.print("Microseconds: ");
  Serial.println((float)(cycles - 1) / 16);
}
 
 
void loop() {
  // delay(1000);
  //digitalWrite(LED_BUILTIN, LOW);
  //delay(1000);
}