int servoPin = A3;

Servo myServo;
int servoPos = 0;

void setup() {
    myServo.attach( A3 );
    pinMode(servoPin, OUTPUT);
    
    
    Particle.function("servo", servoControl);
    Particle.variable(  "servoPos" , &servoPos , INT );
}


void loop() {

    
}


int servoControl(String command)
{
   int newPos = command.toInt();
   servoPos = constrain( newPos, 0 , 180);

   myServo.write( servoPos );

   return 1;
}