#define hijau 4 
#define trig 2
#define echo 15
 void setup() { 
   // put your setup code here, to run once: 
   Serial.begin(115200); 
   pinMode(hijau, OUTPUT); 
   pinMode(trig, OUTPUT); 
   pinMode(echo, INPUT); 
   digitalWrite(hijau, LOW); 
  } 
  void loop() { 
    digitalWrite(trig, LOW); 
    delayMicroseconds(2); 
    digitalWrite(trig, HIGH); 
    delayMicroseconds(10); 
    digitalWrite(trig, LOW); 
    int duration=pulseIn(echo, HIGH); 
    float distance = duration * 0.034/2; 
    Serial.print("Jarak; "); 
    Serial.println(distance); 
    delay(1000); 
    if(distance>50 && distance <=100){ 
      digitalWrite(hijau, HIGH); 
      } 
 else { 
  digitalWrite(hijau, LOW); }  
}