int led1 = D3;

void setup()
{
   //Register Particle function 
   Particle.function("led", ledControl);
   pinMode(led1, OUTPUT);
   digitalWrite(led1, LOW);
}

int ledControl(String times)
{
   int n = times.toInt();

   for (int i = 0; i<n; i++){
        digitalWrite(led1, HIGH);
        delay(500);
        digitalWrite(led1, LOW);
        delay(500);
        }
    digitalWrite(led1, LOW);
    return 1;
}

void loop() {
    
}