void setup() {
  Serial.begin(9600);
    for(int pin = 13; pin >= 4; pin--){
      pinMode(pin, OUTPUT);
    }
}

void loop() {
  int val = analogRead(A0);
  val = map(val,0,1023,0,10);
  Serial.println(val);
  drawTo(val);
  delay(50);

}

void drawTo(byte pos){
  for(int pin = 13; pin >= 4; pin--){
      digitalWrite(pin, LOW);
  }

  for(int pin = 13; pin >= 4; pin--){
    if((13 - pin) >= pos){return;}
    else{digitalWrite(pin, HIGH);}
  }

}