#define ECHO_PIN 3
#define TRIG_PIN 2
#define ECHO_PIN2 11
#define TRIG_PIN2 10
#define pinBuzzer 13
#define LED_R 7
#define LED_L 8

#include <Servo.h>

Servo myservo;  

int potpin = 0;  
int val;    

float readDistanceCMEnter() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

float readDistanceCMExit() {
  digitalWrite(TRIG_PIN2, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN2, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN2, LOW);
  int duration = pulseIn(ECHO_PIN2, HIGH);
  return duration * 0.034 / 2;
}

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(TRIG_PIN2, OUTPUT);
  pinMode(ECHO_PIN2, INPUT);
  Serial.begin(115200);
  pinMode(pinBuzzer, OUTPUT);
  pinMode(LED_L, OUTPUT);
  pinMode(LED_R, OUTPUT);
  myservo.attach(5);  
}

void loop() {
  float distanceEnter = readDistanceCMEnter();
  float distanceExit = readDistanceCMExit();
  Serial.print("Measured distance IN: ");
  Serial.print(readDistanceCMEnter());
  Serial.print("   ");
  Serial.print("Measured distance OUT: ");
  Serial.println(readDistanceCMExit());

  //Kereta datang
  if(distanceEnter <= 200 || distanceExit <= 200){    
    myservo.write(90);                  
    delay(15);
    tone(pinBuzzer, 1000);
    digitalWrite(LED_L, HIGH);
    digitalWrite(LED_R, LOW);
    delay(400);     
    tone(pinBuzzer, 500);
    digitalWrite(LED_L, LOW);
    digitalWrite(LED_R, HIGH);
    delay(400);
  }

  //Kereta pergi
  if(distanceEnter > 200 & distanceExit > 200) {
    myservo.write(0);
    noTone(pinBuzzer); 
    digitalWrite(LED_L, LOW);
    digitalWrite(LED_R, LOW);
  }

/*
  else{
    myservo.write(0);
    noTone(pinBuzzer); 
    digitalWrite(LED_L, LOW);
    digitalWrite(LED_R, LOW);
  }
*/
}