enum livello_pwm {spento, basso, medio, alto} lev;
#include <Arduino.h>
void setup() {
 Serial.begin(115200);
  Serial.println("enum");
  int ch = 0;
  int freq = 5000;
  int res = 8;
  ledcSetup(ch,freq,res);
  ledAttachPin(4,ch);
  analogReadResolution(10); //0-1023
}
void loop() {
int v = analogRead(34);
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");
}
}