Mini traffic light on a breadboard

A small Raspberry Pi Pico project that simulates a traffic light using LEDs, resistors, jumper wires, a button, and a breadboard.

It is intentionally simple: red, yellow, and green LEDs wired to GPIO pins, with a button used to trigger or alter the light sequence.

Why it exists

This was a small physical computing exercise.

Software usually hides the machine behind layers of abstraction. A breadboard does not. If the wiring is wrong, nothing happens. If the resistor is missing, the circuit becomes suspiciously spicy. If the button is noisy, the code has to deal with it.

That makes even a tiny traffic light useful.

What it does

The circuit models a basic traffic light sequence:

• green for go
• yellow for transition
• red for stop
• button input for interaction
• timed state changes controlled by the Pico

What I learned

This project was mainly about getting comfortable with the basics:

• wiring LEDs with resistors
• using Raspberry Pi Pico GPIO pins
• reading a button input
• thinking in simple state machines
• connecting physical circuits to code

Current status

Finished as a small learning project.