ESP32 - Button - Toggle LED

const int BUTTON_PIN = 2;                      // ESP32 pin connected to button's pin
const int LED_PIN    = 13;                     // ESP32 pin connected to LED's pin


int ledState = LOW;                            // the current state of LED
int lastButtonState;                           // the previous state of button
int currentButtonState;                        // the current state of button

void setup() {
  Serial.begin(9600);                          // initialize serial
  pinMode(BUTTON_PIN, INPUT_PULLUP);           // set ESP32 pin to input pull-up mode
  pinMode(LED_PIN, OUTPUT);                    // set ESP32 pin to output mode

  currentButtonState = digitalRead(BUTTON_PIN);
}

void loop() {
  lastButtonState    = currentButtonState;      // save the last state
  currentButtonState = digitalRead(BUTTON_PIN); // read new state

  if(lastButtonState == HIGH && currentButtonState == LOW) {
    Serial.println("The button is pressed");

    ledState = !ledState;// toggle state of LED

    digitalWrite(LED_PIN, ledState);            // control LED arccoding to the toggled state
  }
}
                

const int BUTTON_PIN = 2;                              // GIOP21 pin connected to button
const int LED_PIN    = 13;                             // ESP32 pin connected to LED's pin
const int DEBOUNCE_DELAY = 50;                         // the debounce time; increase if the output flickers

// Variables will change:
int ledState = LOW;     
int lastSteadyState = LOW;                             // the previous steady state from the input pin
int lastFlickerableState = LOW;                        // the previous flickerable state from the input pin
int currentState;                                      // the current reading from the input pin

                       // the following variables are unsigned longs because the time, measured in
                       // milliseconds, will quickly become a bigger number than can be stored in an int.
unsigned long lastDebounceTime = 0;                    // the last time the output pin was toggled

void setup() {
  
  Serial.begin(9600);                                  // initialize serial communication at 9600 bits per second:
  pinMode(BUTTON_PIN, INPUT_PULLUP);                   // initialize the pushbutton pin as an pull-up input
  pinMode(LED_PIN, OUTPUT);                            // set ESP32 pin to output mode
}

void loop() {
  currentState = digitalRead(BUTTON_PIN);              // read the state of the switch/button

                       // check to see if you just pressed the button
                       // (i.e. the input went from LOW to HIGH), and you've waited long enough
                       // since the last press to ignore any noise:
  if (currentState != lastFlickerableState) {          // If the switch/button changed, due to noise or pressing
    lastDebounceTime = millis();                       // reset the debouncing timer
    lastFlickerableState = currentState;               // save the the last flickerable state
  }

                       // whatever the reading is at, it's been there for longer than the debounce
                       // delay, so take it as the actual current state:
  if ((millis() - lastDebounceTime) > DEBOUNCE_DELAY) {
    if(lastSteadyState == HIGH && currentState == LOW)     // if the button state has changed
    {
      Serial.println("The button is pressed");
      ledState = !ledState;// toggle state of LED
      digitalWrite(LED_PIN, ledState);                     // control LED arccoding to the toggled state
    }   
    lastSteadyState = currentState;                        // save the the last steady state
  }
}