Traffic Light Control Circuit Documentation

Summary

This document describes a simple traffic light control circuit that is designed to operate a three-color traffic light system. The circuit uses an Arduino UNO microcontroller to cycle through green, yellow, and red LEDs, simulating a traffic light. The green LED is turned on for 5 seconds, followed by the yellow LED for 2 seconds, and then the red LED for 5 seconds. This sequence repeats indefinitely to mimic the operation of a standard traffic light.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Purpose: Acts as the control unit for the traffic light system.
• 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 (Green, Yellow, Red).
• Purpose: Represents the traffic light being controlled by the Arduino.
• 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.
 * The green LED is 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 redPin = 1;    // Connect to the Red LED
const int yellowPin = 2; // Connect to the Yellow LED
const int greenPin = 3;  // Connect to the Green LED

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

This code is written for the Arduino UNO microcontroller to control the traffic light. The setup() function initializes the pins connected to the LEDs as outputs. The loop() function then controls the state of each LED, turning them on and off in sequence to simulate a traffic light pattern. The delays between the state changes ensure that each LED is on for the correct duration.