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, Push button, Piezo buzzer, HC-SR04 distance. They are already available in the simulator library.

How long does it take?

About 35 minutes, advanced level, in 4 guided steps.

What should I know before starting?

The previous tutorial in the series, “Project: thermostat”, 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

6 · Full projects

Project: intrusion alarm

Advanced35 min

Goal

Detect movement, fire the siren and arm/disarm with a button.

Why it matters

Combines detection, timing, a state machine and signalling.

What you need

Arduino UNO board
5 mm LED
220 Ω resistor
Push button
Piezo buzzer
HC-SR04 distance

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

Steps

01Ultrasonic or light sensor as the detector.
02Arming button with a status indicator.
035 s delay before triggering.
04Siren (buzzer) + flashing LED during the alert.

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, Push button, Piezo buzzer, HC-SR04 distance. They are already available in the simulator library.
How long does it take?: About 35 minutes, advanced level, in 4 guided steps.
What should I know before starting?: The previous tutorial in the series, “Project: thermostat”, 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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