void setup()
{
  pinMode(LED_BUILTIN, OUTPUT); //set up the led inbuilt in 
  attachInterrupt(digitalPinToInterrupt(3), buttonA, RISING);//set the interrupt for button black
  attachInterrupt(digitalPinToInterrupt(18), buttonB, RISING);//set the interrupt for button white
  Serial.begin(9600);
}



void loop()
{
  digitalWrite(LED_BUILTIN,LOW); 
  delay(500);
  digitalWrite(LED_BUILTIN,HIGH);
}

void buttonB(){
  Serial.print("Micro() = ");// when white button is pressed , print micro
  Serial.println(micros());
  
}
void buttonA(){
  Serial.print("millis() = ");//when the black button is pressed, print millis
  Serial.println(millis());
  
}