int trigger=4;
int echo=5;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(25, OUTPUT);
  pinMode(26, OUTPUT);
  pinMode(27, OUTPUT);
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);
}

int finding_distance(){
  digitalWrite(trigger, HIGH);
  delay(100);
  digitalWrite(trigger, LOW);
  float a=pulseIn(echo,HIGH);
  return(a*0.034/2);
}

void loop() {
  int distance=finding_distance();
  Serial.println(distance);
  if(distance>=300)
  {
    Serial.println("you are safe");
    digitalWrite(27,HIGH);
    digitalWrite(25,LOW);
    digitalWrite(26, LOW);
  }
  else if((distance>200)&&(distance<300))
  {
    Serial.println("you are unsafe");
    digitalWrite(26,HIGH);
    digitalWrite(25,LOW);
    digitalWrite(27,LOW);
  }
  else
  {
    Serial.println("you are danger");
    digitalWrite(25,HIGH);
    digitalWrite(26,LOW);
    digitalWrite(27,LOW);
  }

  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}