This program is supposed to act as a Decimal To Binary Converter, the LeD's acting as output.
The problem is that this function returns Garbage Value

```

const int LED1 =1, LED2 =3, LED3 =5;
void setup()
{
  Serial.begin(9600);
  pinMode (LED1, OUTPUT);
  pinMode (LED2, OUTPUT);
  pinMode (LED3, OUTPUT);
}
void loop()
{
  int x = 0;
  x = Serial.read();
  x = x-48;
  switch(x){
    case 0:
      digitalWrite (LED1, LOW);
      digitalWrite (LED2, LOW);
      digitalWrite (LED3, LOW);
      break;
    case 1:
      digitalWrite (LED1, HIGH);
      digitalWrite (LED2, LOW);    
      digitalWrite (LED3, LOW);
      break;
      case 2:
      digitalWrite (LED1, LOW);
      digitalWrite (LED2, HIGH);
      digitalWrite (LED3, LOW);
      break;
      case 3:
      digitalWrite (LED1, HIGH);
      digitalWrite (LED2, HIGH);
      digitalWrite (LED3, LOW);
      break;
      case 4:
      digitalWrite (LED1, LOW);
      digitalWrite (LED2, LOW);
      digitalWrite (LED3, HIGH);
      break;
      case 5:
      digitalWrite (LED1, HIGH);
      digitalWrite (LED2, LOW);
      digitalWrite (LED3, HIGH);
      break;
      case 6:
      digitalWrite (LED1, LOW);
      digitalWrite (LED2, HIGH);
      digitalWrite (LED3, HIGH);
      break;
      case 7:
      digitalWrite (LED1, HIGH);
      digitalWrite (LED2, HIGH);
      digitalWrite (LED3, HIGH);
      break;
  }
 Serial.write(x); 
}

```