// FROM: https://www.digikey.com/en/maker/tutorials/2022/how-to-use-arduino-interrupts-to-detect-user-inputs
#include <Arduino.h>

volatile bool execute = false;

void onDetectInterrupt(){
  /* The Arduino calls this function when
     it detects a falling edge on pin 2. */
  execute = true;
}

void setup(){
  pinMode(2, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(2), onDetectInterrupt, FALLING);
  Serial.begin(9600);
}

void loop()
{
  /* Other code */
  if(execute) {
    // display sometinh when the interrpt happened
    Serial.println("Hello world!");
	  // Don't forget to reset the flag
	  execute = false;
  }
}