void setup()
{
  pinMode(A0, INPUT);
  pinMode(13, OUTPUT);
  Serial.begin (9600);
}

void loop()
{
  int Potenciometro = analogRead (A0);
 int verso = map (Potenciometro,0,1023,1023,0);
  Serial.print ("\n P: ");
  Serial.print (Potenciometro);
  Serial.print (" V: ");
  Serial.print (verso);
  delay(500);

}