int g=13;
int y=14;
int r=34;
int trigger=4;
int echo=5;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
 
  pinMode(trigger, OUTPUT);
  pinMode(g, OUTPUT);
  pinMode(y, OUTPUT);
  pinMode(r, 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(g,HIGH);
    delay(200);
    digitalWrite(g,LOW);
  }
  else if(distance>=200 && distance<300){
    Serial.println("You are unsafe.");
    digitalWrite(y,HIGH);
    delay(200);
    digitalWrite(y,LOW);
  }else if(distance<300){
    Serial.println("You are in danger.");
    digitalWrite(r,HIGH);
    delay(200);
    digitalWrite(r,LOW);
  }
  
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}