Converts Z-Uno pin number to interrupt index. digitalPinToInterrupt(pin)
pin: Z-Uno pin number. Look at the pinout page for more details. interrupt index
const byte ledPin = 13;
const byte interruptPin = 2;
volatile byte state = LOW;

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(interruptPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(interruptPin), blink, CHANGE);

void loop() {
  digitalWrite(ledPin, state);

void blink() {
  state = !state;