Building a Simple Traffic Light System with Arduino Uno

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Welcome to Maker Tech Lab! In this tutorial, we will build a simple traffic light system using an Arduino Uno. This project will help you understand how to control multiple LEDs with an Arduino to simulate traffic light signals.

Materials Needed

Traffic light display Module Traffic light display Module Buy at Amazon
Arduino Uno Arduino Uno Buy at Amazon
Breadboard Breadboard Buy at Amazon
Jumper Wires Jumper Wires Buy at Amazon
220 ohm Resistor 220 ohm Resistor Buy at Amazon
  1. Connect the LEDs (if you are using regular leds): Place the three LEDs on the breadboard. Connect the anode of each LED to a digital pin on the Arduino (e.g., pins 8, 9, and 10). Connect the cathode (shorter leg) of each LED to a 220-ohm resistor, and then connect the other end of each resistor to the ground (GND) on the Arduino.
  1. Connect the 3 Leds Traffic light display Module: Connect G,Y,R pins from traffic display module to Arduino (e.g., pins 8 (Red) , 9 (Yellow) , and 10 (Green) ). Connect GND to ground (GND) on the Arduino.

The Code

Here’s the Arduino code to control the traffic light system:

Copy Code 


const int redPin = 8;

const int yellowPin = 9;

const int greenPin = 10;

void setup() {

  pinMode(redPin, OUTPUT);

  pinMode(yellowPin, OUTPUT);

  pinMode(greenPin, OUTPUT);

}

void loop() {

  // Turn on the red LED and turn off the others

  digitalWrite(redPin, HIGH);

  digitalWrite(yellowPin, LOW);

  digitalWrite(greenPin, LOW);

  delay(5000); // Red light for 5 seconds


  // Turn on the yellow LED and turn off the others

  digitalWrite(redPin, LOW);

  digitalWrite(yellowPin, HIGH);

  digitalWrite(greenPin, LOW);

  delay(2000); // Yellow light for 2 seconds


  // Turn on the green LED and turn off the others

  digitalWrite(redPin, LOW);

  digitalWrite(yellowPin, LOW);

  digitalWrite(greenPin, HIGH);

  delay(5000); // Green light for 5 seconds

}

Explanation

  • Pin Setup: We define the pins where the red, yellow, and green LEDs are connected.
  • Setup Function: We initialize the LED pins as outputs.
  • Loop Function: This function cycles through the red, yellow, and green LEDs, turning each LED on for a specific duration to simulate a traffic light sequence.

Uploading the Code

  1. Open the Arduino IDE.
  2. Copy and paste the code into the IDE.
  3. Select the correct board and port from the Tools menu.
  4. Click the upload button.

Conclusion

Congratulations! You’ve built a simple traffic light system using an Arduino Uno. This project is a great introduction to controlling multiple outputs and can be expanded to more complex systems. Stay tuned for more tutorials and exciting projects at Maker Tech Lab!

Happy making!

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