Arduino Project

Arduino Automatic Railway Ramp with IR Sensors and Dual Servo

Course Introduction

In this lesson, you’ll learn how to build an automatic railway crossing using two IR Sensor Modules and two servo motors.

When a train passes the first sensor, the barriers lower to block the road.After the train reaches the second sensor, the barriers rise again, simulating a real railway crossing system.

Note

If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.

1.1 Install Arduino IDE(Important)
1.2 Introduction of Arduino IDE

Required Components

In this project, we need the following components:

SN

COMPONENT INTRODUCTION

QUANTITY

PURCHASE LINK

1

Arduino UNO R4 Minima

1

BUY

2

USB Type-C cable

1

×

3

Breadboard

1

BUY

4

Wires

Several

BUY

5

IR Obstacle Avoidance Sensor Module

2

BUY

6

Digital Servo Motor

2

BUY

Wiring

2.webp__PID:57e5443e-3f97-4a6b-8cf8-ab918c159360

Common Connections:

Digital Servo Motor 1
Connect to breadboard’s positive power bus.
Connect to breadboard’s negative power bus.
Connect to 9 on the Arduino.

Digital Servo Motor 2
Connect to breadboard’s positive power bus.
Connect to breadboard’s negative power bus.
Connect to 10 on the Arduino.

IR Obstacle Avoidance Sensor Module 1
OUT: Connect to 2 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

IR Obstacle Avoidance Sensor Module 2
OUT: Connect to 3 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

Writing the Code

Note
You can copy this code into Arduino IDE.
Don’t forget to select the board(Arduino UNO R4 Minima) and the correct port before clicking the Upload button.


#include 

// IR sensor pins
const int IR_ENTRY_PIN = 2;
const int IR_EXIT_PIN = 3;

// Servo pins
const int SERVO_1_PIN = 9;
const int SERVO_2_PIN = 10;

// Servo angles
const int GATE_DOWN_ANGLE = 0;
const int GATE_UP_ANGLE = 90;

// Most IR obstacle sensors output LOW when an object is detected.
// If your sensor works the opposite way, change LOW to HIGH.
const int IR_DETECTED_STATE = LOW;

// Debounce
const unsigned long debounceDelay = 200;

Servo gateServo1;
Servo gateServo2;

bool gateOpen = false;

bool lastEntryState = HIGH;
bool lastExitState = HIGH;

unsigned long lastEntryTime = 0;
unsigned long lastExitTime = 0;

void setup() {
  pinMode(IR_ENTRY_PIN, INPUT);
  pinMode(IR_EXIT_PIN, INPUT);

  gateServo1.attach(SERVO_1_PIN);
  gateServo2.attach(SERVO_2_PIN);

  closeGate();
}

void loop() {
  bool currentEntryState = digitalRead(IR_ENTRY_PIN);
  bool currentExitState = digitalRead(IR_EXIT_PIN);

  unsigned long now = millis();

  // IR Sensor 1 detects the train: raise the barriers
  if (lastEntryState != IR_DETECTED_STATE && currentEntryState == IR_DETECTED_STATE) {
    if (now - lastEntryTime > debounceDelay) {
      openGate();
      lastEntryTime = now;
    }
  }

  // IR Sensor 2 detects the train: lower the barriers
  if (lastExitState != IR_DETECTED_STATE && currentExitState == IR_DETECTED_STATE) {
    if (now - lastExitTime > debounceDelay) {
      closeGate();
      lastExitTime = now;
    }
  }

  lastEntryState = currentEntryState;
  lastExitState = currentExitState;
}

void openGate() {
  gateOpen = true;
  gateServo1.write(GATE_UP_ANGLE);
  gateServo2.write(GATE_UP_ANGLE);
}

void closeGate() {
  gateOpen = false;
  gateServo1.write(GATE_DOWN_ANGLE);
  gateServo2.write(GATE_DOWN_ANGLE);
}