#define ECHO_PINA 3
#define TRIG_PINA 2
#define ECHO_PINB 6
#define TRIG_PINB 4
#define pinBuzzer 5
#define led1 12
#define led2 13

#include <Servo.h>

Servo myservo;  

int potpin = 0;  
int val;    

float readDistanceCMA() {
  digitalWrite(TRIG_PINA, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PINA, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PINA, LOW);
  int durationA = pulseIn(ECHO_PINA, HIGH);
  return durationA * 0.034 / 2;
}
float readDistanceCMB() {
  digitalWrite(TRIG_PINB, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PINB, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PINB, LOW);
  int durationB = pulseIn(ECHO_PINB, HIGH);
  return durationB * 0.034 / 2;
}


void setup() {
  pinMode(TRIG_PINA, OUTPUT);
  pinMode(ECHO_PINA, INPUT);
  pinMode(TRIG_PINB, OUTPUT);
  pinMode(ECHO_PINB, INPUT);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  Serial.begin(115200);
  pinMode(pinBuzzer, OUTPUT);
  myservo.attach(9);  
}

void loop() {
  float distanceA = readDistanceCMA();
  Serial.print("Measured distance: ");
  Serial.println(readDistanceCMA());
  float distanceB = readDistanceCMB();
  Serial.print("Measured distance: ");
  Serial.println(readDistanceCMB());
  //kereta datang
  if(distanceA <= 200 || distanceB <=200){    
    myservo.write(90);                  
    delay(15);
   tone(pinBuzzer, 1000);
    digitalWrite(led1, HIGH);
    digitalWrite(led2, LOW);
    delay(200);     
    digitalWrite(led1, LOW);
    digitalWrite(led2, HIGH);
    tone(pinBuzzer, 500);
    delay(200);
  }
  //kereta lewat
  if(distanceA > 200 && distanceB > 200){    
    myservo.write(0); 
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);                 
    
    noTone(pinBuzzer);
  }
 /* else{
    myservo.write(0);
    noTone(pinBuzzer); 
  }
  */
  }