#include <Servo.h>

#define TRIGGER_PIN_1 9  // Trigger pin for Ultrasonic Sensor 1
#define ECHO_PIN_1 8    // Echo pin for Ultrasonic Sensor 1
#define TRIGGER_PIN_2 4  // Trigger pin for Ultrasonic Sensor 2
#define ECHO_PIN_2 5     // Echo pin for Ultrasonic Sensor 2
#define SERVO_PIN 7     // Servo motor control pin

Servo gateServo;
long duration_1, duration_2;
int distance_1, distance_2;

void setup() {
  pinMode(TRIGGER_PIN_1, OUTPUT);
  pinMode(ECHO_PIN_1, INPUT);
  pinMode(TRIGGER_PIN_2, OUTPUT);
  pinMode(ECHO_PIN_2, INPUT);
  gateServo.attach(SERVO_PIN);
  gateServo.write(90); // Initialize servo position to 90 degrees (closed gate)
  Serial.begin(9600);
}

void loop() {
  // Measure distance from Ultrasonic Sensor 1
  digitalWrite(TRIGGER_PIN_1, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN_1, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN_1, LOW);
  duration_1 = pulseIn(ECHO_PIN_1, HIGH);
  distance_1 = duration_1 * 0.034 / 2; // Calculate distance in cm

  // Measure distance from Ultrasonic Sensor 2
  digitalWrite(TRIGGER_PIN_2, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN_2, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN_2, LOW);
  duration_2 = pulseIn(ECHO_PIN_2, HIGH);
  distance_2 = duration_2 * 0.034 / 2; // Calculate distance in cm

  // Check if a train is detected by either sensor
  if (distance_1 < 4|| distance_2 < 4) { // Adjust the threshold distance as needed
    closeGate();
    delay(4000); // Wait for 5 seconds (gate closed)
    openGate();
  }
}

void closeGate() {
  gateServo.write(0); // Close the gate (adjust the angle as needed)
}

void openGate() {
  gateServo.write(90); // Open the gate (adjust the angle as needed)
}