potenciometro arduino jfx

//bem10jfx.blogspot.com

int pinled_5=5; //PWM
int v=0;
void setup() {
Serial.begin(9600);
pinMode(pinled_5, OUTPUT);
Serial.println("Iniciando");

}
void loop() {


     while (Serial.available()> 0) {
         v = Serial.parseInt();/*convertendo*/
          Serial.println();
         Serial.print("Pulso ");
         Serial.println(v);
         delay(250);
         int vlx=v/51;
         Serial.print("Volts ");
          Serial.println((int)vlx);

          delay(250);

     if(Serial.available()=="255"){
      Serial.println("Valor maximo 5 volts");
          }
     if(Serial.available()=="0"){
      Serial.println("Valor minimo 0 volts");
          }
     }

   analogWrite(pinled_5, v);
     delay(250);
}