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, Light sensor (LDR), MPU6050 IMU. They are already available in the simulator library.

How long does it take?

About 15 minutes, intermediate level, in 3 guided steps.

What should I know before starting?

The previous tutorial in the series, “Hardware interrupts”, 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

3 · Outputs & actuators

PWM: dimming an LED

Intermediate15 min

Goal

Breathe an LED from 0 to 255 with analogWrite().

Why it matters

PWM fakes an analog voltage by chopping the signal very fast — the basis of dimmers and motor drives.

What you need

Arduino UNO board
5 mm LED
220 Ω resistor
Light sensor (LDR)
MPU6050 IMU

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

Steps

01Place the LED on a PWM pin (3, 5, 6, 9, 10 or 11).
02Ramp a variable from 0 to 255 with a for loop.
03Apply analogWrite(pin, value), then ramp back down.

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, Light sensor (LDR), MPU6050 IMU. They are already available in the simulator library.
How long does it take?: About 15 minutes, intermediate level, in 3 guided steps.
What should I know before starting?: The previous tutorial in the series, “Hardware interrupts”, 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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