#include<Servo.h>
Servo gerbang;
const int trigPin =7;
const int echoPin =6;
const int ledMerah =3;
const int ledHijau =4;
const int buzzer =8;
void setup() {
gerbang.attach(9);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(ledMerah, OUTPUT);
pinMode(ledHijau, OUTPUT);
pinMode(buzzer, OUTPUT);
gerbang. write(0);
digitalWrite(ledMerah, LOW);
digitalWrite(ledHijau, HIGH);
}
void loop() {
// Kirim sinyal ultrasonik
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Baca pantulan
long durasi = pulseIn(echoPin, HIGH);
// Hitung jarak
int jarak = durasi * 0.034 / 2;
// Jika ada objek dekat
if (jarak < 20) {
gerbang.write(90);
digitalWrite(ledMerah, HIGH );
digitalWrite(ledHijau, HIGH);
tone(buzzer, 1000);
} else {
gerbang.write(0);
digitalWrite(ledMerah, HIGH);
digitalWrite(ledHijau, HIGH);
noTone(buzzer);
}
delay(500);
}