Description
Objective:
Create a traffic light system using an Arduino Uno and LEDs, simulating a real-world traffic signal with Red, Yellow, and Green LEDs.
Materials Needed:
- Arduino Uno
- 1 Red LED
- 1 Yellow LED
- 1 Green LED
- 3x 330Ω Resistors
- Breadboard
- Jumper Wires
- USB Cable (to power and program the Arduino)
How It Works:
- The Red LED lights up for 5 seconds (Stop).
- The Yellow LED lights up for 2 seconds (Prepare to Stop/Go).
- The Green LED lights up for 5 seconds (Go).
- The cycle repeats infinitely.
Circuit Setup:
1. Red LED:
- Connect the long leg (anode) to digital pin 13 via a 330Ω resistor.
- Connect the short leg (cathode) to GND.
2. Yellow LED:
- Connect the long leg (anode) to digital pin 12 via a 330Ω resistor.
- Connect the short leg (cathode) to GND.
3. Green LED:
- Connect the long leg (anode) to digital pin 11 via a 330Ω resistor.
- Connect the short leg (cathode) to GND.
Code:
// Define LED pins
const int redLED = 13;
const int yellowLED = 12;
const int greenLED = 11;
void setup() {
// Set LED pins as outputs
pinMode(redLED, OUTPUT);
pinMode(yellowLED, OUTPUT);
pinMode(greenLED, OUTPUT);
}
void loop() {
// Red light ON for 5 seconds
digitalWrite(redLED, HIGH);
digitalWrite(yellowLED, LOW);
digitalWrite(greenLED, LOW);
delay(5000);
// Yellow light ON for 2 seconds
digitalWrite(redLED, LOW);
digitalWrite(yellowLED, HIGH);
digitalWrite(greenLED, LOW);
delay(2000);
// Green light ON for 5 seconds
digitalWrite(redLED, LOW);
digitalWrite(yellowLED, LOW);
digitalWrite(greenLED, HIGH);
delay(5000);
}
Demonstration Steps
Upload the Code:
- Connect the Arduino to your computer and upload the provided code via the Arduino IDE.
Power the Circuit:
- Power the Arduino through the USB cable or an external power source.
Observe the Traffic Light Sequence:
- The LEDs will light up in the following pattern:
- Red LED: ON for 5 seconds.
- Yellow LED: ON for 2 seconds.
- Green LED: ON for 5 seconds.