enum livello_pwm {spento, basso, medio, alto} lev;
void setup() {
  int ch = 0;
  int freq = 1000;
  int res = 8
  Serial.begin(115200);
  Serial.println("enum");
  ledcSetup(ch,freq,res);
  ledAttachPin(25,ch);
  analogReadResolution(10);
}
void loop() {
  int v = analogRead(33);
  Serial.println(v);
  delay(300);
  if (v<200)lev=spento;
  else if (v<400)lev=basso;
  else if (v<800)lev=medio;
  else lev=alto;
  if (lev==spento){
    Serial.println("off");
    ledcWrite(0,0);
  }
  if (lev==basso){
    ledcWrite(0,70);
    Serial.println("basso");
  }
  if (lev==medio){
    ledcWrite(0,140);
    Serial.println("medio");
  }
  if (lev==alto){
    ledcWrite(0,255);
    Serial.println("on");
  }
}