int led1= D2;
void setup() {
   pinMode(led1, OUTPUT);
   digitalWrite(led1, LOW);
   Particle.function("led", ledControl);
}
void loop() {
}   

int ledControl(String command)
{
   if(command == "HIGH"){	   
	   for(int i=0; i<3; i++){
	          digitalWrite(led1, HIGH);
	          delay(500);
	          digitalWrite(led1, LOW);
	          delay(500);
	   }
   }else if(command == "LOW"){ 
            digitalWrite(led1, LOW);
	   return 0;
   }else{
	   return -1;
   }
   return 1;
}