byte incomingByte= 0;
byte led=8;
void setup()
{
pinMode(led,OUTPUT);
Serial.begin(9600);
}
void loop()
{
if (Serial.available()> 0)
{
incomingByte = Serial.read();
if(incomingByte==49)
    {
  Serial.println("LED ON"); digitalWrite(led,HIGH);
    }
else
   {
  Serial.println("LED OFF");   digitalWrite(led,LOW);
   }
}
}