#02beginner

Traffic Controller

Build a traffic light that cycles through green, yellow, and red

Watch the circuit build itself: components drop in, wires connect, and the output comes alive.

Components

Everything you need for this project.

1x Red LED

1x Yellow LED

1x Green LED

220Ω

3x 220Ω resistors

6x jumper wires

How It Works

Sequential logic, timing, and multiple output control. Introduction to state machines through traffic light phases.

InputInternal Timer
ProcessingESP32-S3 cycles through traffic light state machine
Output3 LEDs cycle G→Y→R

What You Build

Three LEDs on pins D1–D3, each through a 220Ω resistor, cycling through a traffic light sequence.

African Context

Traffic management is a growing challenge in rapidly urbanizing African cities like Lagos, Nairobi, and Dar es Salaam. Understanding traffic light logic is the first step toward smart city infrastructure.

What You'll See

LEDs cycle: Green ON for 3 seconds, Yellow for 1 second, Red for 3 seconds, repeat.