int po = 14;
int va = 27;
float reading ;
float distance ;
int red =26;
int yellow =25;
int green = 12;


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(po, OUTPUT);
  pinMode(va, INPUT);
  pinMode(red,OUTPUT);
  pinMode(yellow, OUTPUT);
  pinMode(green, OUTPUT);
}

void loop() {
  digitalWrite(po, HIGH);
  delay(100);
    digitalWrite(po, LOW);
  Serial.println("singnal out");;
  reading = (pulseIn(va,HIGH));
distance = (reading*0.034/2);
Serial.println(distance); 
Serial.println(("singnal in"));
if (distance<100)
{
  Serial.println("denger");
  digitalWrite(yellow, LOW);
  digitalWrite(red, HIGH);
  digitalWrite(green, LOW);
}
else if (distance<200)
{
  Serial.println("alert");
    digitalWrite(green, LOW);
    digitalWrite(yellow, HIGH);
    digitalWrite(red, LOW);
  }
else if (distance>310)
{
  Serial.println("safe");
  digitalWrite(red, LOW);
  digitalWrite(yellow, LOW);
  digitalWrite(green, HIGH);
}
else
{
  digitalWrite(red, LOW);
  digitalWrite(yellow, LOW);
  digitalWrite(green, LOW);
}
  // put your main code here, to run repeatedly:
  delay(3000); // this speeds up the simulation
}