int trig = 13;
int echo = 12;
int distance;


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(15, OUTPUT);
  pinMode(16, OUTPUT);
  pinMode(17, OUTPUT);
}

void loop() {

  digitalWrite(trig,HIGH);
  delay(100);
  digitalWrite(trig, LOW);
  int reading =(pulseIn(echo,HIGH));
  distance = (reading*0.034/2);
  if(distance<100)
{
  digitalWrite(15, HIGH);
  digitalWrite(16, LOW);
  digitalWrite(17, LOW);
  Serial.println("Danger");
}
else if(distance<200)
{
  digitalWrite(15, LOW);
  digitalWrite(16, HIGH);
  digitalWrite(17, LOW);
  Serial.println("Alart");
}
else if (distance<300)
{
  digitalWrite(15, LOW);
  digitalWrite(16, LOW);
  digitalWrite(17, HIGH);
  Serial.println("safe");
}
Serial.println(distance);
}