void setup() 
{
  Serial.begin(9600);
  pinMode(A0,INPUT);
  for(int i = 11; i<=13; i++)pinMode(i,OUTPUT);
}

void loop() 
{
  delay(100);
  int data = analogRead(A0);
  Serial.print("Data = "+ String(data));
  float volt = data * 5.0/1023;
  Serial.println("/t Volt = " + String(volt) + "v");
  if(volt <= 1.6) 
  {
    digitalWrite(11, HIGH);
    digitalWrite(12, HIGH);
    digitalWrite(13, LOW);
  }
  else 
  if(volt <= 3.2 && volt > 1.6) 
  {
    digitalWrite(12, HIGH);
    digitalWrite(11, LOW);
    digitalWrite(13, HIGH);
  }
  else 
  {
    digitalWrite(13, HIGH);
    digitalWrite(12, LOW);
    digitalWrite(11, HIGH);
  }
}