#define buttonPin 17
#define ledPin 21

bool ledState = LOW;
bool lastButtonState = HIGH;  // HIGH because of INPUT_PULLUP
bool currentButtonState;

void setup() {
  Serial.begin(115200);
  pinMode(buttonPin, INPUT_PULLUP); // Button to GND
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, ledState);   // LED initially OFF
  Serial.println("System Initialized");
}

void loop() {
  currentButtonState = digitalRead(buttonPin);

  // Toggle only when button goes from HIGH -> LOW
  if (lastButtonState == HIGH && currentButtonState == LOW) {
    ledState = !ledState;
    digitalWrite(ledPin, ledState);
    Serial.println(ledState ? "LED ON" : "LED OFF");
    delay(200); // Debounce delay
  }

  lastButtonState = currentButtonState;
}