#define LED_PIN PC13
#define BUTTON_PIN PA0

bool ledState = false;  // false = OFF
bool lastButtonState = HIGH;
unsigned long lastDebounceTime = 0;
const unsigned long debounceDelay = 50; // milliseconds

void setup() {
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP); // Button to GND
  digitalWrite(LED_PIN, HIGH);       // Start LED OFF (PC13 active low)
}

void loop() {
  bool reading = digitalRead(BUTTON_PIN);

  // Detect changes
  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }

  // After debounce time, check if it was a press
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (lastButtonState == HIGH && reading == LOW) {
      ledState = !ledState;
      digitalWrite(LED_PIN, ledState ? LOW : HIGH); // Active low LED
    }
  }

  lastButtonState = reading;
}