int trigger=19;
int echo=18;
int light=14;
int buzzer=15;
int servo=16;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(servo, OUTPUT);

}

int Ultra_sonic(){
  digitalWrite(trigger, HIGH);
  delay(100);
  digitalWrite(trigger, LOW);
 float recieved= pulseIn(echo, HIGH);
 float converted=(recieved*0.034/2)+1;
 return(converted);

}

void loop() {
  // put your main code here, to run repeatedly:
  int actual_distance=Ultra_sonic();
  Serial.println(actual_distance);
  delay(1000);
if(actual_distance==300){
  digitalWrite(light, HIGH);
  delay(2000);
  digitalWrite(light, LOW);
  tone(buzzer,4000);
  delay(1000);
  noTone(buzzer);
  digitalWrite(servo, HIGH);
  delay(5000);
  digitalWrite(servo, LOW);
  Serial.println("please wait the door is opening ");
}
}