#include <Servo.h>

int echopin = A0;
int trigpin = 7;
int ledred = 8;
int ledgrn = 9;
int Time;
int Distance;

Servo myservo;

void setup() {
  // put your setup code here, to run once:
  pinMode(trigpin, OUTPUT);
  pinMode(echopin, INPUT);
  pinMode(ledred, OUTPUT);
  pinMode(ledgrn, OUTPUT);
  myservo.attach(11);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigpin, LOW);
  digitalWrite(trigpin, HIGH);
  digitalWrite(trigpin, LOW);
  Time = pulseIn(echopin, HIGH);
  Distance = Time*0.0172;

  if (Distance>30){
    myservo.write(90);
    digitalWrite(ledgrn, LOW);
    digitalWrite(ledred, HIGH);
  } else {
    myservo.write(0);
    digitalWrite(ledred, LOW);
    digitalWrite(ledgrn, HIGH);
    delay(500);
    digitalWrite(ledgrn, LOW);
    delay(500);
  }
}