#define echoPin 2
#define trigPin 4

int maximumRange = 300;
int minimumRange = 00;
long duration, distance;

void setup() {
Serial.begin (9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(7, OUTPUT);
pinMode(8, OUTPUT);
pinMode(9,OUTPUT);
}

void loop() {
/* penentuan jarak. */
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);

// perhitungan untuk dijadikan jarak
distance = duration/58.2;

/* jika jarak melebihi 300 cm,
kirim keterangan "diluar jangkauan" */

if (distance >= maximumRange || distance <= minimumRange){
Serial.println("Di Luar jangkauan");
}
else{

/* kirim hasil pembacaan jarak melalui serial monitor */
Serial.print("Jarak : ");
Serial.print(distance);
Serial.println("cm ");

delay(100);
}

if(distance <= 100){
  digitalWrite(7, HIGH);
  digitalWrite(8, LOW);
  digitalWrite(9, LOW);
}
if(distance > 100 && distance < 200){
  digitalWrite(7, LOW);
  digitalWrite(8, HIGH);
  digitalWrite(9, LOW);

}
if(distance > 100 && distance < 200){
  digitalWrite(7, HIGH);
  digitalWrite(8, HIGH);
  digitalWrite(9, HIGH);
}
}