const int buttonPin = 18; // GPIO pin for button
const int ledPin = 2;     // GPIO pin for LED
volatile bool ledState = false;  // Use volatile for shared variables

void IRAM_ATTR handleInterrupt() {
  ledState = !ledState;  // Toggle LED state
}

void setup() {
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);
 
  attachInterrupt(digitalPinToInterrupt(buttonPin), handleInterrupt, FALLING);  
  Serial.begin(115200);
}

void loop() {
  digitalWrite(ledPin, ledState);  // Update LED based on interrupt
  
  Serial.print("LED State: ");
  Serial.println(ledState ? "ON" : "OFF");
  
  delay(100);  // Small delay for serial output stability
}