int leds[] = {2,3,4,5,6,7,8,9};
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
Serial.println("Hello World");
for (int i = 0; i < 8; i++)
{
  pinMode(leds[i], OUTPUT);
}
}

void loop() 
{
  int allapot = analogRead(A0);
  int potErtek=map(allapot,0,1023,0,7);
  switch(potErtek) {
  case 0: digitalWrite (leds[0],HIGH); delay(200);digitalWrite(leds[0],LOW);
  break;
  case 1: digitalWrite (leds[1],HIGH); delay(200);digitalWrite(leds[1],LOW);
  break;
  case 2: digitalWrite (leds[2],HIGH); delay(200);digitalWrite(leds[2],LOW);
  break;
  case 3: digitalWrite (leds[3],HIGH); delay(200);digitalWrite(leds[3],LOW);
  break;
  case 4: digitalWrite (leds[4],HIGH); delay(200);digitalWrite(leds[4],LOW);
  break;
  case 5: digitalWrite (leds[5],HIGH); delay(200);digitalWrite(leds[5],LOW);
  break;
  case 6: digitalWrite (leds[6],HIGH); delay(200);digitalWrite(leds[6],LOW);
  break;
  case 7: digitalWrite (leds[7],HIGH); delay(200);digitalWrite(leds[7],LOW);
  break;
  default:Serial.println(potErtek);
  break;
  
  }
}