void setup(){
  pinMode(9, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
}
void loop(){
  pwm_ms(0.5);
digitalWrite(11, HIGH);
delay(1000);
digitalWrite(11, LOW);

pwm_ms(1.47);
digitalWrite(12, HIGH);
delay(1000);
digitalWrite(12, LOW);

pwm_ms(2.4);
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
}
void pwm_ms(float time){
  time=(int)(time*1000);
  digitalWrite(9, HIGH);
  delayMicroseconds(time);
  digitalWrite(9, LOW);
  delayMicroseconds(2000-time);
}