Traffic Light Control Circuit Documentation

Summary

This document describes a simple traffic light control circuit, which is designed to operate a three-light traffic signal system. The circuit uses an Arduino UNO microcontroller to control the timing and switching of the traffic lights, which include green, yellow, and red LEDs. The Arduino UNO cycles through the lights in a predefined sequence: green light for 5 seconds, yellow light for 2 seconds, and red light for 5 seconds. This sequence repeats indefinitely to simulate a traffic light system.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Purpose: Acts as the central controller for the traffic light system, managing the timing and state changes of the LEDs.
• Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0-A5, SCL, SDA, AREF, D0-D13.

Traffic Light

• Description: A simple traffic light module with three LEDs representing the green, yellow, and red lights.
• Purpose: Displays the traffic light states as controlled by the Arduino UNO.
• Pins: Green, Yellow, Red, GND.

Wiring Details

Arduino UNO

• GND: Connected to the GND pin of the Traffic Light.
• D3: Connected to the Green pin of the Traffic Light.
• D2: Connected to the Yellow pin of the Traffic Light.
• D1: Connected to the Red pin of the Traffic Light.

Traffic Light

• Green: Connected to D3 on the Arduino UNO.
• Yellow: Connected to D2 on the Arduino UNO.
• Red: Connected to D1 on the Arduino UNO.
• GND: Connected to GND on the Arduino UNO.

Documented Code

/*
 * This Arduino sketch controls a traffic light system with three LEDs: green, 
 * yellow, and red. The green LED stays on for 5 seconds, followed by the yellow 
 * LED for 2 seconds, and then the red LED for 5 seconds. This cycle repeats 
 * indefinitely.
 */

// Pin definitions
const int greenPin = 3;
const int yellowPin = 2;
const int redPin = 1;

void setup() {
  // Initialize the digital pins as outputs
  pinMode(greenPin, OUTPUT);
  pinMode(yellowPin, OUTPUT);
  pinMode(redPin, OUTPUT);
}

void loop() {
  // Turn on the green LED
  digitalWrite(greenPin, HIGH);
  delay(5000); // Wait for 5 seconds
  digitalWrite(greenPin, LOW);

  // Turn on the yellow LED
  digitalWrite(yellowPin, HIGH);
  delay(2000); // Wait for 2 seconds
  digitalWrite(yellowPin, LOW);

  // Turn on the red LED
  digitalWrite(redPin, HIGH);
  delay(5000); // Wait for 5 seconds
  digitalWrite(redPin, LOW);
}

Filename: sketch.ino

Description: The code provided is an Arduino sketch that defines three output pins corresponding to the green, yellow, and red LEDs of the traffic light. In the setup() function, these pins are initialized as outputs. The loop() function then controls the state of each LED, turning them on and off in sequence with appropriate delays to simulate a traffic light.