void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(trigPin, OUTPUT);
pinMode(echopin, INPUT);
pinMode(8, OUTPUT);
pinMode(10, OUTPUT);
pinMode(12, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
/* 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(12, HIGH);
digitalWrite(10, LOW);
digitalWrite(8, LOW);

}
if(distance> 100 && distance < 200){
digitalWrite(12, LOW);
digitalWrite(10, HIGH);
digitalWrite(8, LOW);

}
if(distance >=200){
digitalWrite(12, LOW);
digitalWrite(10, LOW);
digitalWrite(8, HIGH);
}
}