This document provides code for creating a basic traffic light system using an Arduino Uno board. It defines pin assignments for the red, yellow, and green LEDs. The setup function initializes the pins as outputs. The loop function calls changeLights every 15 seconds. ChangeLights turns the lights on and off in sequence: green off and yellow on for 3 seconds, yellow off and red on for 5 seconds, red and yellow on for 2 seconds, then red and yellow off with green on.

1. ARDUINO TRAFFIC LIGHTS

2. ARDUINO UNO

5. int red = 11; int yellow = 12; int green = 13;

6. • void setup(){
• pinMode(red,OUTPUT);
• pinMode(yellow,OUTPUT);
pinMode(green,OUTPUT); }

8. • int red = 13; int yellow = 12; int green =
11;
• void setup(){
pinMode(red,OUTPUT);
pinMode(yellow,OUTPUT);
pinMode(green,OUTPUT); }

9. • void loop(){
• changeLights(); delay(15000); }
• void changeLights(){
• // green off, yellow for 3 seconds digitalWrite(green,HIGH);
• digitalWrite(yellow,LOW);
• delay(3000);
• // turn off yellow, then turn red on for 5 seconds
• digitalWrite(yellow,LOW);
digitalWrite(red,HIGH);
delay(5000);
// red and yellow on for 2 seconds (red is already on though)
digitalWrite(yellow,HIGH); delay(2000); // turn off red and yellow,
then turn on green digitalWrite(yellow,LOW); digitalWrite(red,LOW);
digitalWrite(green,HIGH); }

10. • void changeLights(){
• // green off, yellow for 3 seconds
digitalWrite(green,HIGH);
digitalWrite(yellow,LOW); delay(3000);

11. •
•
•
•
•
// turn off yellow, then turn red on for 5 seconds
digitalWrite(yellow,LOW); digitalWrite(red,HIGH);
delay(5000);
// turn off red and yellow, then turn on green
digitalWrite(yellow,LOW); digitalWrite(red,LOW);
digitalWrite(green,HIGH); }

12. ARDUINO SOFTWARE

13. Download

14. Execute

16. Recognize Arduino (1)

17. Update the controllers

18. BLINK CODE

19. BLINK CODE

20. Arduino can speak with Processing