const int buttonPin = 13;  
const int ledPin = 15;     

volatile bool ledState = LOW; 

void setup() {
  pinMode(ledPin, OUTPUT);              
  pinMode(buttonPin, INPUT_PULLUP);     

  attachInterrupt(digitalPinToInterrupt(buttonPin), toggleLED, RISING); 
}

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


void toggleLED() {
  ledState = !ledState;  
}