#define LED_PIN 2
#define POT_PIN 34
#define BTN_PIN 14

bool ledState = false;
bool lastBtn = LOW;

void setup() {
  pinMode(BTN_PIN, INPUT_PULLDOWN);
  ledcAttach(LED_PIN, 5000, 8);
}

void loop() {

  bool btn = digitalRead(BTN_PIN);

  if (btn == HIGH && lastBtn == LOW) {
    ledState = !ledState;
    delay(50);
  }

  lastBtn = btn;

  if (ledState) {
    int val = analogRead(POT_PIN);
    int pwm = map(val, 0, 4095, 0, 255);

    ledcWrite(LED_PIN, pwm);
  } else {
    ledcWrite(LED_PIN, 0);
  }

  delay(10);
}