#include <Stepper.h>
const int stepsPerRevolution = 200; 
Stepper myStepper(stepsPerRevolution, 2, 3, 4, 5);
#define TRIG 11
#define ECHO 10
int kecepatan = 100;
void setup() {
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  Serial.begin(9600);
}

void loop() {

  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  int duration = pulseIn(ECHO, HIGH);
  int jarak = duration / 58;
  Serial.print("Distance in CM: ");
  Serial.println(jarak);
   if(jarak <= 20 ){
    kecepatan = 1;
  }
  else if(jarak > 20 && jarak <=60 ){
    kecepatan = 20;
  }
  else if(jarak > 60 && jarak  <=100 ){
    kecepatan = 40;
  }
  else{
      kecepatan = 100;
  } 
   myStepper.setSpeed(kecepatan);
  myStepper.step(stepsPerRevolution);
  delay(100);
}