#define LED 4

void setup() {


  Serial.begin(115200);
  Serial.println("ready");
  pinMode(LED, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(21),displaymic,HIGH);
  attachInterrupt(digitalPinToInterrupt(20),displaymil,HIGH);
 
}
void displaymic(){
  Serial.write("micros = ");
  Serial.println(micros());
  

}
void displaymil(){
  Serial.write("millis = ");
  Serial.println(millis());
}
void loop() {

  digitalWrite(LED, HIGH);
  delay(500);
  digitalWrite(LED, LOW);
  delay(500);

}