const int analogPin = A0;   // the pin that the potentiometer is attached to
int pin ;
int ledLevel;
void setup() {
  Serial.begin(9600);
    pin=4;
    while (pin<=11){
      pinMode(pin, OUTPUT);
      pin = pin + 1;
      Serial.println(pin);
  }
}

void loop() {
  // read the potentiometer:
  int sensorReading = analogRead(analogPin);
  // map the result to a range from 0 to the number of LEDs:
  int ledLevel = map(sensorReading, 0, 1023, 0, 7);
  Serial.println(ledLevel);
  switch(ledLevel){

    case 0:
      digitalWrite(4,HIGH);
      digitalWrite(5,LOW);
      digitalWrite(6,LOW);
      digitalWrite(7,LOW);
      digitalWrite(8,LOW);
      digitalWrite(9,LOW);
      digitalWrite(10,LOW);
      digitalWrite(11,LOW);
      break;
    case 1:
      digitalWrite(4,HIGH);
      digitalWrite(5,HIGH);
      digitalWrite(6,LOW);
      digitalWrite(7,LOW);
      digitalWrite(8,LOW);
      digitalWrite(9,LOW);
      digitalWrite(10,LOW);
      digitalWrite(11,LOW);
      break;
    case 2:
      digitalWrite(4,HIGH);
      digitalWrite(5,HIGH);
      digitalWrite(6,HIGH);
      digitalWrite(7,LOW);
      digitalWrite(8,LOW);
      digitalWrite(9,LOW);
      digitalWrite(10,LOW);
      digitalWrite(11,LOW);
      break;
    case 3:
      digitalWrite(4,HIGH);
      digitalWrite(5,HIGH);
      digitalWrite(6,HIGH);
      digitalWrite(7,HIGH);
      digitalWrite(8,LOW);
      digitalWrite(9,LOW);
      digitalWrite(10,LOW);
      digitalWrite(11,LOW);
      break;
    case 4:
      digitalWrite(4,HIGH);
      digitalWrite(5,HIGH);
      digitalWrite(6,HIGH);
      digitalWrite(7,HIGH);
      digitalWrite(8,HIGH);
      digitalWrite(9,LOW);
      digitalWrite(10,LOW);
      digitalWrite(11,LOW);
      break;
    case 5:
      digitalWrite(4,HIGH);
      digitalWrite(5,HIGH);
      digitalWrite(6,HIGH);
      digitalWrite(7,HIGH);
      digitalWrite(8,HIGH);
      digitalWrite(9,HIGH);
      digitalWrite(10,LOW);
      digitalWrite(11,LOW);
      break;
    case 6:
      digitalWrite(4,HIGH);
      digitalWrite(5,HIGH);
      digitalWrite(6,HIGH);
      digitalWrite(7,HIGH);
      digitalWrite(8,HIGH);
      digitalWrite(9,HIGH);
      digitalWrite(10,HIGH);
      digitalWrite(11,LOW);
      break;
    case 7:
      digitalWrite(4,HIGH);
      digitalWrite(5,HIGH);
      digitalWrite(6,HIGH);
      digitalWrite(7,HIGH);
      digitalWrite(8,HIGH);
      digitalWrite(9,HIGH);
      digitalWrite(10,HIGH);
      digitalWrite(11,HIGH);
      break;
  }
  
}