Arduino Project
Barrier Gate 2.0
Course Introduction
In this lesson, you’ll learn how to use an ultrasonic sensor module, a digital servo motor, and Traffic light LED Module with the Arduino Board to build an intelligent barrier gate system version 2.0.
When the ultrasonic sensor module detects a vehicle, the traffic light will change from red to green, and the gate will rise, allowing the car to pass.
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:
Wiring
Common Connections:
Traffic light LED
R: Connect to 11 on the Arduino.
Y: Connect to 10 on the Arduino.
G: Connect to 9 on the Arduino.
GND: Connect to breadboard’s negative power bus.
Digital Servo Motor
Connect to breadboard’s positive power bus.
Connect to breadboard’s negative power bus.
Connect to 12 on the Arduino.
Ultrasonic Sensor Module
Trig: Connect to 3 on the Arduino.
Echo: Connect to 4 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.
I2C LCD 1602
SDA: Connect to A4 on the Arduino.
SCL: Connect to A5 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.
To install the library, use the Arduino Library Manager and search for LiquidCrystal I2C and install it.
Don’t forget to select the board(Arduino UNO R4 WIFI) and the correct port before clicking the Upload button.
#include
#include
#include
// Define pin connections
const int trigPin = 3;
const int echoPin = 4;
const int redPin = 11;
const int yellowPin = 10;
const int greenPin = 9;
const int servoPin = 12;
// Create LCD and Servo objects
Servo myServo;
LiquidCrystal_I2C lcd(0x27, 16, 2); // 16x2 I2C LCD
void setup() {
Serial.begin(9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(redPin, OUTPUT);
pinMode(yellowPin, OUTPUT);
pinMode(greenPin, OUTPUT);
myServo.attach(servoPin);
myServo.write(90); // Start with gate closed
lcd.init();
lcd.backlight();
lcd.clear();
lcd.setCursor(2, 0); // Center "System Ready"
lcd.print("System Ready");
delay(1000);
}
void loop() {
// Send ultrasonic pulse
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Measure duration of echo
long duration = pulseIn(echoPin, HIGH);
float distance = duration * 0.034 / 2;
Serial.print("Distance: ");
Serial.print(distance);
Serial.println(" cm");
if (distance < 10) { // Vehicle detected
digitalWrite(redPin, LOW);
digitalWrite(yellowPin, HIGH);
digitalWrite(greenPin, LOW);
myServo.write(90); // Keep gate closed
lcd.clear();
lcd.setCursor(2, 0); // Center "Please Wait"
lcd.print("Please Wait");
delay(1000); // Wait 1 seconds with yellow light
digitalWrite(yellowPin, LOW);
digitalWrite(greenPin, HIGH);
myServo.write(0); // Open gate
lcd.clear();
lcd.setCursor(1, 0); // Center "You Can Pass!"
lcd.print("You Can Pass!");
delay(1500); // Wait 1.5 seconds with green light
digitalWrite(greenPin, LOW);
digitalWrite(redPin, HIGH);
myServo.write(90); // Close gate
lcd.clear();
lcd.setCursor(4, 0); // Center "Welcome"
lcd.print("Welcome");
} else {
digitalWrite(redPin, HIGH);
digitalWrite(yellowPin, LOW);
digitalWrite(greenPin, LOW);
myServo.write(90); // Keep gate closed
lcd.clear();
lcd.setCursor(4, 0); // Center "Welcome"
lcd.print("Welcome");
}
delay(300); // Small delay before next reading
}