unsigned long second;

void setup() {
  ledcSetup(0, 1000, 8);
  ledcAttachPin(2, 0);
  pinMode(4, INPUT);
  Serial.begin(9600);
  Serial.println("Hello, ESP32!");
}

void loop() {
  int A = analogRead(4);
  int B = map(A, 0, 4095, 0, 255);
  ledcWrite(0, B);
  dacWrite(25, B);
  if(millis() > second)
  {
    second += 1000;
    int C = map(B, 0, 255, 0, 100);
    Serial.print("Brightness: ");
    Serial.print(C);
    Serial.println("%");
  }
}