int val=0;
int relay=8;
void setup()
{
  Serial.begin(9600);
  pinMode(relay,OUTPUT);
}
void loop()
{
  if (Serial.available())
  {
    val=Serial.read();
    Serial.print("Read value is : ");
    Serial.println(val);
    if(val=49)
  {
    digitalWrite(relay,LOW);
    Serial.println("Bulb is ON");
  }
  else if (val==48){
    digitalWrite(relay,HIGH);
    Serial.println("Bulb is OFF");
  }
}
}