const int NEW_LINE = 10;
int servo = 5;

void setup(){
  Serial.begin(9600);
  pinMode(servo, OUTPUT);  
}

void loop(){
  if(Serial.available()>0){
    String command = Serial.readStringUntil(NEW_LINE);
    Serial.println(command.toInt());
    servo_pwm(servo, command.toInt());

  }
}

void servo_pwm(int pin, int dur){
  int LoopCount = 25;  // setting this lower than 25, will cause power instabilities

  for(int i = 0; i < LoopCount; ++i){
    digitalWrite(pin, HIGH);
    delayMicroseconds(dur);
    digitalWrite(pin, LOW);
    delayMicroseconds(20000 - dur);
  }
}