Arduino Project

Arduino Traffic Light Project V3

Kit purchase

Looking for parts? Check out our all-in-one kits below — packed with components, beginner-friendly guides, and tons of fun.

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Name	Includes Arduino board	PURCHASE LINK
Ultimate Sensor Kit	Arduino Uno R4 Minima	BUY
Elite Explorer Kit	Arduino Uno R4 WiFi	BUY
3 in 1 Ultimate Starter Kit	Arduino Uno R4 Minima	BUY

Course Introduction

In this lesson, you’ll learn how to build a traffic light system with a safety barrier using the Arduino UNO R4 WiFi, a TM1637 4-digit display, a traffic light module, and a servo motor.

The display counts down the red and green light phases, while the servo automatically lowers the barrier during the red light and raises it during the green light.

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/Arduino UNO R4 WIFI	1	BUY
2	USB Type-C cable	1	×
3	Breadboard	1	BUY
4	Wires	Several	BUY
5	4-Digit Segment Display Module	1	BUY
6	Traffic Light LED	1	BUY
7	Digital Servo Motor	1	BUY

Wiring

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Common Connections:

Traffic light LED
R: Connect to 10 on the Arduino.
Y: Connect to 11 on the Arduino.
G: Connect to 12 on the Arduino.
GND: Connect to breadboard’s negative power bus.

4-Digit Segment Display Module
CLK: Connect to 3 on the Arduino.
DIO: Connect to 2 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

Digital Servo Motor
VCC: Connect to breadboard’s positive power bus.
GND: Connect to breadboard’s negative power bus.
Data: Connect to 9 on the Arduino.

Writing the Code

Note
You can copy this code into Arduino IDE.
To install the library, use the Arduino Library Manager and search for Adafruit SSD1306 and TM1637Display and install it.
Don’t forget to select the board(Arduino UNO R4 Minima/WIFI) and the correct port before clicking the Upload button.

#include <TM1637Display.h>
#include <Servo.h>

// TM1637 pin definitions
#define CLK 3
#define DIO 2

// Traffic light pins
const int redPin = 10;
const int greenPin = 12;

// Servo pin
const int servoPin = 9;

// Create display object
TM1637Display display(CLK, DIO);

// Create servo object
Servo barrierServo;

void setup() {
  // Setup traffic light pins
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);

  // Initialize display
  display.setBrightness(7);

  // Initialize servo
  barrierServo.attach(servoPin);

  // Initial position: barrier raised
  barrierServo.write(0);

  delay(500);
}

void loop() {

  // =========================
  // Red light phase - 10s
  // =========================
  digitalWrite(redPin, HIGH);
  digitalWrite(greenPin, LOW);

  // Lower the barrier
  barrierServo.write(90);

  countdown(10);

  // =========================
  // Green light phase - 10s
  // =========================
  digitalWrite(redPin, LOW);
  digitalWrite(greenPin, HIGH);

  // Raise the barrier
  barrierServo.write(0);

  countdown(10);
}

// Countdown function
void countdown(int seconds) {
  for (int i = seconds; i > 0; i--) {
    display.showNumberDec(i, true, 2, 2);
    delay(1000);
  }

  display.clear();
}

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Arduino Project

Arduino Traffic Light Project V3

Kit purchase

Course Introduction

Required Components

Wiring

Common Connections:

Writing the Code

Arduino Project

Arduino Traffic Light Project V3

Kit purchase

Course Introduction

Required Components

Wiring

Common Connections:

Writing the Code

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