#define LED_PIN PA5
#define BUTTON_PIN PC13

bool ledState = false;

void setup() {
    pinMode(LED_PIN, OUTPUT);
    pinMode(BUTTON_PIN, INPUT_PULLUP);
}

void loop() {
    static int lastState = HIGH;

    int currentState = digitalRead(BUTTON_PIN);

    if (lastState == HIGH && currentState == LOW) {
        ledState = !ledState;
        digitalWrite(LED_PIN, ledState);

        delay(50); // chống dội phím
    }

    lastState = currentState;
}