/*
 * Debounce sketch for ESP32
 * A switch connected to pin 2 lights the built-in LED
 * Debounce logic prevents misreading of the switch state
 */

const int inputPin = 2;         // the number of the input pin
const int debounceDelay = 10;   // debounce time in milliseconds
bool last_button_state = LOW;   // last state of the button
int ledState = LOW;             // on or off (HIGH or LOW)

// debounce function to stabilize switch readings
bool debounce(int pin)
{
  bool state;
  bool previousState;

  previousState = digitalRead(pin);          // store switch state
  for(int counter = 0; counter < debounceDelay; counter++)
  {
    delay(1);                    // wait for 1 ms
    state = digitalRead(pin);    // read the pin
    if(state != previousState)
    {
      counter = 0;               // reset the counter if state changes
      previousState = state;     // save current state
    }
  }
  // switch state stable longer than debounce period
  return state;
}

void setup()
{
  pinMode(inputPin, INPUT_PULLUP);   // enable internal pull-up resistor
  pinMode(LED_BUILTIN, OUTPUT);     // declare LED pin as output
}

void loop()
{
  bool button_state = debounce(inputPin);  // check debounced button state

  // if button state changed and button was pressed
  if(last_button_state != button_state && button_state == HIGH)
  {
    // toggle LED state
    ledState = !ledState;
    digitalWrite(LED_BUILTIN, ledState);
  }
  last_button_state = button_state;  // update last button state
}