Traffic Light Simulator - Arduino

#arduino #womenintech #geospatial #beginners

Simulating a traffic light using LEDs and Arduino, I did the project with my 8-year-old son! He found it so cool.

COMPONENTS

Arduino UNO
Breadboard (Generic)
Jumper Wires (Generic)
LED (Red, Green, Yellow)
Arduino USB 2.0 Data Cable
Resistor 100 ohm

COMPONETS SETUP

IDE used: Arduino IDE

This simple "for beginners " uses an Arduino and LEDs to simulate a traffic light.

Define variables, use lights by colour name:

// variables
int red = 10;
int yellow = 9;
int green = 8;

Create a function to configure the output colours of the LEDs (Red, Yellow, Green):

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

This pinMODE function, configures the Arduino to use a defined pin as an output.

Write the code for the actual logic behind the traffic light simulation. The given values are in milliseconds

void loop(){
    changeLights();
    delay(15000);
}
void changeLights(){
    // green off, yellow on for 3 seconds
    digitalWrite(green, LOW);
    digitalWrite(yellow, HIGH);
    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);
    delay(3000);
}