Arduino Traffic Light Controller

Project Overview

This beginner project introduces you to basic Arduino programming, focusing on pinMode, digitalWrite, and delay functions. We will construct a model of a standard intersection using LEDs.

Components Required

• 1x Arduino Uno
• 1x Breadboard
• 3x Red LEDs, 3x Yellow LEDs, 3x Green LEDs
• 9x 220-ohm Resistors
• Jumper Wires

Wiring Guide

Connect the long leg (anode) of each LED to a digital pin on the Arduino (e.g., Pins 2 through 10) through a 220-ohm resistor. Connect all the short legs (cathodes) to the ground rail on your breadboard, and run a wire from the ground rail to the GND pin on the Arduino.

Source Code

int red1 = 2;
int yellow1 = 3;
int green1 = 4;

void setup() {
  pinMode(red1, OUTPUT);
  pinMode(yellow1, OUTPUT);
  pinMode(green1, OUTPUT);
}

void loop() {
  digitalWrite(green1, HIGH);
  delay(5000);
  digitalWrite(green1, LOW);
  
  digitalWrite(yellow1, HIGH);
  delay(2000);
  digitalWrite(yellow1, LOW);
  
  digitalWrite(red1, HIGH);
  delay(5000);
  digitalWrite(red1, LOW);
}