//Project name - Automation of railway crossing to prevent accidents on the track between train and any other vechile 
//Project by - Kunwar Ranveer
//Class - 8
//Student of Denobili School, CMRI, Dhanbad, Jharkhand.
//Email ID - [email protected]
//Contact no. - +91 9304152407

#include <Servo.h>//Library for servo motor is required naming (servo)
Servo servo1;
//defining of all the pins
int trigPin = 9;
int echoPin = 8;
long distance;
long duration;
#define Led1 13
#define Led2 12
int Buzzer = 6;
void setup() 
{
servo1.attach(7); 
 pinMode(trigPin, OUTPUT);//Sensor
 pinMode(echoPin, INPUT);//Sensor
 pinMode(Led1, OUTPUT);//Red light
 pinMode(Led2, OUTPUT);//Green light
 pinMode(Buzzer, OUTPUT);//Buzzer
}
void loop()
{
  ultra_sonic();
  servo1.write(90);
  if(distance <=300)//distance is less than 300
  {
  servo1.write(270);
  digitalWrite(Led1, HIGH );//Switches on Red light when distance is less than 300
  digitalWrite(Led2, LOW);//Switches off Green light when distance is less than 300
  digitalWrite(Buzzer, HIGH);//Rings the buzzer to indicate that the gate is closing and train is coming 
  }
  if(distance >=300)//distance is more than 300
  {
    digitalWrite(Led1, LOW);//Switches off Red light when distance is more than 300
    digitalWrite(Led2, HIGH);//Switches on Green light when distance is more than 300
    digitalWrite(Buzzer, LOW);//Rings the buzzer to indicate that the gate is opening and train has gone 
  }
}
void ultra_sonic()
{
  //control of Ultra-sonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration*0.034/2;
  }