Do I need to buy hardware for this tutorial?

No. Everything runs in the browser: Circuitly simulates the board, the components and the code. Real hardware is optional if you want to rebuild the circuit afterwards.

Which components are used?

Arduino UNO board, 5 mm LED, 220 Ω resistor. They are already available in the simulator library.

How long does it take?

About 15 minutes, intermediate level, in 4 guided steps.

What should I know before starting?

The previous tutorial in the series, “Two alternating LEDs”, is enough preparation. No software install is required.

Is the code provided and checked?

The simulator checks your wiring and your code automatically at every step, and shows the commented solution if you get stuck.

All tutorials

1 · First steps

5-LED chaser

Intermediate15 min

Goal

Run a light across 5 LEDs using a for loop and an array.

Why it matters

Array + loop avoids copying the same code five times: your first algorithmic building block.

What you need

Arduino UNO board
5 mm LED
220 Ω resistor

Nothing to buy: every component below is simulated in the browser.

Steps

01Place 5 LEDs on pins 2 to 6.
02Declare int leds[5] = {2,3,4,5,6};
03In setup(), configure them with a for loop.
04In loop(), light them one after another, then start over.

This tutorial runs inside the Circuitly simulator: your wiring and your code are checked automatically at every step.

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Frequently asked questions

Do I need to buy hardware for this tutorial?: No. Everything runs in the browser: Circuitly simulates the board, the components and the code. Real hardware is optional if you want to rebuild the circuit afterwards.
Which components are used?: Arduino UNO board, 5 mm LED, 220 Ω resistor. They are already available in the simulator library.
How long does it take?: About 15 minutes, intermediate level, in 4 guided steps.
What should I know before starting?: The previous tutorial in the series, “Two alternating LEDs”, is enough preparation. No software install is required.
Is the code provided and checked?: The simulator checks your wiring and your code automatically at every step, and shows the commented solution if you get stuck.

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