int led[10] = { 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}; // Assign the pins for the leds 
   
  int leftChannel = 0; 
  int left, i; 
   
  void setup() 
  { 
  for (i = 0; i < 10; i++) 
    pinMode(led[i], OUTPUT); 
  Serial.begin(9600);  
  } 
   
  void loop() 
  { 
  left = analogRead(leftChannel); 
   
  Serial.println(left); 
   
  left = left / 2; 
   
    if (left == 0)   
     { 
     for(i = 0; i < 10; i++) 
       { 
       digitalWrite(led[i], LOW); 
        
       } 
    } 
     
    else 
    { 
     for (i = 0; i < left; i++)  
      { 
       digitalWrite(led[i], HIGH); 
        
      } 
       
      for(i = i; i < 10; i++)   
       { 
        digitalWrite(led[i], LOW); 
         
       } 
    } 
  }