What is Arduino? Your first gateway to electronics and robots

A light that switches on by itself when it gets dark, a plant that is watered automatically when the soil dries out, a small car that avoids walls with nobody driving it. Projects like these once needed engineers and specialised labs; today a lower-secondary student can build them on the kitchen table. The biggest reason for that change is a small blue electronics board called Arduino. In this article we explain what Arduino is, where it came from, what the board is made of, the most popular kinds, and what you need to start – with first-project ideas suitable for beginners of different ages, and safety advice that protects both the board and you.

What is Arduino?

Arduino is an open-source electronics platform with two parts: an electronics board carrying a microcontroller – a very small computer on a single chip – and a free programming environment where you write instructions on your computer and send them to the board over a USB cable. After that the board works on its own, reading what is happening around it from sensors – light, temperature, distance – and controlling actuators such as lights, motors, screens and sounds.

The project began in the mid-2000s at an interaction design institute in the Italian town of Ivrea. The aim was to give design and art students, not just engineers, a cheap and easy tool for building interactive prototypes. Because the board’s design and software are open source, huge communities grew up around it, along with thousands of libraries and tutorials and compatible boards from many manufacturers.

How does it work? Input, processing and output

Every Arduino project, however complex, follows the same pattern: the board reads inputs, decides according to the program you wrote, then produces outputs. And it repeats this a very large number of times every second.

An example: in a “smart light” project, a light sensor measures how bright the room is, the Arduino reads the value, and the program checks: is the value below a certain threshold? If so, it sends a signal that turns the lamp on; otherwise it turns it off.

Where is Arduino used?

In education

Arduino is used in schools and universities around the world to teach programming, physics and electronics in a tangible way. When students see that a line they wrote made a light switch on or a motor turn, abstract ideas become an experience they can touch – one of the strongest motivations for learning.

In the smart home and gardening

Hobbyists build systems that monitor temperature and humidity, water plants automatically according to soil moisture, send an alert when a door opens, and switch on lights in response to movement – small projects that solve real problems at home or in the garden.

In prototyping

Designers and engineers in companies use Arduino to try out an idea for a device quickly and cheaply before investing in manufacturing it. A prototype answers the question “does the idea work?” before large sums are spent.

In art and interactive design

This is the field Arduino was born in: artworks whose lights and sounds change with visitors’ movements, clothing that lights up, and new musical instruments.

A tour of the Arduino Uno board

The Uno is the most popular board for beginners, and most tutorials start with it. Its main parts are:

• The ATmega328P microcontroller: the board’s “brain”, running at 16 MHz, with a small memory that stores your program even after the power is disconnected.
• Digital pins (14): they handle just two states, on or off. Six of them support PWM, which simulates in-between values – for example, controlling the brightness of a light or the speed of a motor.
• Analogue pins (6): they read varying values from sensors and turn them into numbers from 0 to 1023.
• The USB port: for uploading programs from the computer; it also powers the board.
• The external power jack: for running the board from a battery or adapter without the computer.
• The 5V, 3.3V and GND power pins: for powering connected sensors and small parts.
• The reset button: restarts the program from the beginning.
• A small built-in LED: connected to pin 13, which you will use in your first experiment.

The following video from Fireship sums up the idea of Arduino in a hundred seconds:

The popular boards: which should you choose?

Our advice for a beginner: start with an Uno or a compatible board. The early challenges are about understanding, not the board’s capabilities, and the wealth of tutorials for it saves you a great deal of time.

What do you need to start?

• An Arduino Uno or compatible board, with the right USB cable.
• A breadboard for connecting parts without soldering.
• Jumper wires in different colours.
• A set of LEDs and resistors of various values, including 220 ohms.
• Push buttons, a potentiometer, a light sensor and a small buzzer.
• A computer with the free Arduino IDE installed.

On the market you will find “genuine” boards made by Arduino itself and “compatible” boards made by other companies from the same open design, usually at a lower price. Both work with the same programming environment, but some compatible boards use a different USB chip that needs an extra driver installed on the computer. Buying a genuine board supports the open-source project that develops the environment and libraries free for everyone.

Many shops sell “starter kits” that bundle these parts with the board, which is a practical choice. Just make sure the kit includes the board, the cable and a breadboard.

Starter project ideas

1. The blinking LED: the “hello world” of electronics. We explain it step by step in your first Arduino program.
2. Traffic lights: three LEDs switching in the right order and timing.
3. A smart light: a light sensor switches the LED on in the dark.
4. A doorbell: a button that plays a tone when pressed.
5. A distance meter: an ultrasonic sensor shows the distance on the computer – a gateway to sensors in robots.

Safety rules

Arduino runs on a safe low voltage, but some rules protect the board and you: always disconnect the power before changing connections. Never connect an LED without a resistor, or you may damage the LED or the pin. Never connect a motor directly to the board’s pins; motors need a driver circuit and a separate power supply, as we explain in motors in robots. And never go near mains electricity with its high voltage; beginner projects all run on low voltage from USB or batteries. For younger learners: work with an adult present, especially when using batteries and cutting tools.

To understand what happens inside circuits, read circuit basics. In the robotics and embedded systems course at Badr Academy Education we start from the first circuit and build up to a robot that moves and makes decisions, with follow-up from the instructor. For further resources visit the learning library, and for a plan that suits your age and level try the Find your path tool.