int LED = LED_BUILTIN;
int sensorPin = A2;
int potValue = A2;
float voltageValue = 0.;

void setup (){
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop(){
 potValue = analogRead(sensorPin);
 digitalWrite(LED, HIGH);
 delay(potValue);
 digitalWrite(LED, LOW);
 delay(potValue);
 voltageValue = 5.*(potValue / 1023);
 Serial.println(voltageValue);
}