const int trigPin = 13;
const int echoPin = 12;
const int ledPin = 10;

void setup() {
Serial.begin(9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(ledPin, OUTPUT);
}

void loop() {
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);

long durasi = pulseIn(echoPin, HIGH);
long jarak = (durasi * 0.0343) / 2;

Serial.print("Distance: ");
Serial.print(jarak);
Serial.println(" cm");

if (jarak < 20) {
Serial.println("LED ON");
digitalWrite(ledPin, HIGH);
} else {
Serial.println("LED OFF");
digitalWrite(ledPin, LOW);
}

delay(500);
}