int trigPin = 3;
int echoPin = 2;
int red_buzz = 9;
int green = 8;
int distance;
int time;
void setup() {
  // put your setup code here, to run once:
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(red_buzz, OUTPUT);
  pinMode(green, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigPin, LOW);
  digitalWrite(trigPin, HIGH);
  time = pulseIn(echoPin, HIGH);
  distance = time*0.0172;
  if (distance > 30){
    digitalWrite(green, HIGH);
    digitalWrite(red_buzz, LOW);
  }
  else{
    digitalWrite(green, LOW);
    digitalWrite(red_buzz, HIGH);
    delay(100);
    digitalWrite(red_buzz, LOW);
    delay(100);
    digitalWrite(red_buzz, HIGH);
    delay(100);
    digitalWrite(red_buzz, LOW);
    delay(100);
  }
}