int trigger=4;
int echo=5;
int red =25;
int orange =26;
int green =27;
int buzzer=17;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
 
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(red, OUTPUT);
  pinMode(orange, OUTPUT);
  pinMode(green, OUTPUT);
}

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(green, HIGH);
    digitalWrite(red, LOW);
    digitalWrite(orange, LOW);
    noTone(buzzer);
  }else if (distance >= 200 && distance <300){
    Serial.println("You are unsafe");
    digitalWrite(green, LOW);
    digitalWrite(red, LOW);
    digitalWrite(orange,  HIGH);
    noTone(buzzer);
  }else{
    Serial.println("You are danger");
    digitalWrite(green, LOW);
    digitalWrite(red,  HIGH);
    digitalWrite(orange, LOW);
    tone(buzzer, 2000);
  }

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