Traffic lights

This project is simple and easy to build, even for beginners. I used a ready-made traffic light module, but you can also use three separate LEDs. My traffic light already had the resistors built in, but if you use three LEDs, I recommend adding three 220Ω resistors.

Required components:

• Arduino board (I used a Nano, but any Arduino-compatible microcontroller will work)

• LEDs: red, yellow, green (or a pre-assembled traffic light module, like the one I used)

• 220Ω resistor (if you use external LEDs)

• Jumper wires

• Breadboard (optional, but recommended)

Connections:

• Red LED → pin 8 → through a 220Ω resistor → GND

• Yellow LED → pin 9 → through a 220Ω resistor → GND

• Green LED → pin 10 → through a 220Ω resistor → GND

The LED anode (long leg) connects to the Arduino pin, and the cathode (short leg) connects to GND.

Code:

// Definim pinii LED-urilor

const int ledRosu = 8;

const int ledGalben = 9;

const int ledVerde = 10;

// Timpul fiecărui LED (în milisecunde)

const int timpRosu = 3000;

const int timpGalben = 1000;

const int timpVerde = 3000;

void setup() {

pinMode(ledRosu, OUTPUT);

pinMode(ledGalben, OUTPUT);

pinMode(ledVerde, OUTPUT);

}

void loop() {

// Verde aprins

digitalWrite(ledVerde, HIGH);

digitalWrite(ledGalben, LOW);

digitalWrite(ledRosu, LOW);

delay(timpVerde);

// Galben aprins

digitalWrite(ledVerde, LOW);

digitalWrite(ledGalben, HIGH);

digitalWrite(ledRosu, LOW);

delay(timpGalben);

// Roșu aprins

digitalWrite(ledVerde, LOW);

digitalWrite(ledGalben, LOW);

digitalWrite(ledRosu, HIGH);

delay(timpRosu);

}