Aakash Yadav | 28 Jul, 2023

What is Arduino? A Beginner's Guide to Understand it


If you’re an engineering student or professional, you might have heard of the platform Arduino. The name has been a buzzword among electronics students lately.

What is Arduino? Well, before, working with electronics required a strong understanding of mathematics, physics, and other concepts. But with the advent of technology, various tools and equipment have changed the electronics working model so that immense knowledge is no longer required. 

One of those advent pieces of equipment is “Arduino,” which helps students understand electronics concepts at an early stage of their career. You might have a lot of questions, like what is Arduino used for, and what language does Arduino use? 

We'll get into all about Arduino electronics shortly.

This article introduces you the Arduino meaning and its history. It will also cover every type of Arduino board available, Arduino microprocessors, why to use Arduino, components of Arduino UNO, and constraints and applications of Arduino. 

Let’s get started. 


What is Arduino?

Arduino is an open-source platform that helps circuit developers build electronic projects. It consists of both hardware and software. Arduino hardware is a programmable circuit board called a microcontroller. Arduino software is an IDE (integrated development environment) through which developers write and upload the code to the microcontroller. 

We can feed a program with a set of instructions to the Arduino board that can carry out simple to complex tasks. Traditional programmable circuit boards require separate hardware to load the code onto the board. But Arduino eliminates the need for hardware; instead, it uses a simple USB cable to load code onto the Arduino board. 

The Arduino board enables developers to feed the program in the simplified version of the C++ language, making it easier for them to learn and code. 

Arduino UNO Starter Kit Specifications



Arduino Hardware

The hardware part of the Arduino is its programmable circuit board. You might have come across various Arduino boards in your work, but the most commonly used Arduino board is Arduino UNO. All Arduino boards have a microcontroller known as a small computer, which is the heart of Arduino.

So, when learning about Arduino, it’s essential to learn about microcontrollers and how to use them. The Arduino microcontroller is responsible for reading different inputs and controlling the outputs. 


Arduino Software

Arduino’s software is called Arduino IDE. You can download the software on your computer and program the Arduino boards to perform various tasks accordingly. 

IDE is similar to a text editor, where you write instructions for the Arduino board.


Arduino Code

Apart from hardware and software, the third most important aspect of Arduino is its code, also known as a sketch. You can write the code in the Arduino IDE and load it onto the board.

You might be wondering what language Arduino uses for scripting the code. Arduino has its native language analogous to C++, called Arduino Programming Language. Any program developed using Arduino Programming Language is called sketch and saved in a file with the .ino extension. 

To write instructions for Arduino boards, you must possess a basic understanding of C and C++ programming languages.

Together, hardware, software, and code make up Arduino. 

Arduino Step by Step: Getting Started

Types of Arduino Boards

You can create different boards, each with additional capabilities using Arduino. It’s an open-source hardware, allowing anyone to make changes and create various derivatives of Arduino boards. These changes let you add multiple functionalities. 


Below are some common types of Arduino even computer novices can use:

1. Arduino UNO (R3)

Arduino Uno R3

The UNO is one of the most accessible options to get your feet wet in the electronics field. It depends on an ATmega328P-based microcontroller, and features the following:

  • 14 digital I/O pins
  • 6 pins for PWM
  • 6 pins for analog inputs
  • a reset button
  • a USB connection

Arduino UNO (R3) has everything it needs to hold up the microcontroller. All you need to do is attach it to your computer via USB cable and provide the supply with an AC-to-DC adapter or battery to make it work.


2. Arduino Nano

arduino nano
This board has connections similar to UNO but is based on ATmega328P and ATmega628 microcontrollers. This small, flexible, and reliable board with a mini USB and is great for creating projects. 

This board comes with 8 analog pins, 14 digital pins with an I/O pin, 6 power pins & 2 RST (reset) pins. 


3. Arduino Micro

Arduino Micro

This type of Arduino has an ATmega32U4-based microcontroller with 20 sets of pins, 7 of which are for PWM, and 12 analog input pins. The Arduino Micro also comes with an ICSP header, RST button, small USB connection, and 16-MHz crystal oscillator. 

The miniature of the Leonardo board, this Arduino Micro has a built-in USB connection. 


4. Arduino Lilypad

Arduino Lilypad


The Lily Pad Arduino board is designed as an e-textile technology. This hardware is expanded by Leah “Buechley” and designed by “Leah and SparkFun.” Each board is designed with substantial connecting pads, having a smooth back that you can sew into clothing using conductive thread. This Arduino has I/O, power, and sensor boards. A nice bonus is that this Arduino board is even washable!


5. Arduino RedBoard

Arduino RedBoard


You can use the mini-b USB to program this board. This board is flat on the back like the previous Lilypad, making placement easy. You can efficiently use this board with Windows 8 without having to change the settings. Further, you just need to plug this board into your system and write code to upload on the board. You can control this board using a barrel jack along with the USB cable.


6. Arduino Mega R3

Arduino Mega R3

The Arduino Mega R3 is an expanded form of Arduino UNO and comes with a digital I/O pin. It also has 14 pins that work as PWM o/ps, 6 pins for analog inputs, a reset button, a power jack, and a USB connection. 

You can use a USB cable to communicate with a computer. This Arduino board is ideal for designing projects that require substantial digital inputs and outputs.


7. Arduino Leonardo

Arduino Leonardo

This Arduino was introduced as the first development board with one microcontroller and a USB. It is the simplest and cheapest type of Arduino, making it extremely suitable for novices. 

What is on the Arduino Board?

Among all Arduino boards available on the market, the easiest and commonly used board is Arduino UNO. Some of these boards may have a different look and feel, but all have some standard components. So, let us discuss its fundamental components here. 

Arduino UNO

It is a simple and commonly used prototyping board suitable even for beginners to get along with electronics. Being the basic one, it is essential for every electronics developer to know its different components. 

UNO comes with an ATmega328P microcontroller. It has two variants: one has a through-hole microcontroller connection and the other has a surface mount type. In the through-hole model, you can replace its chip with a new one in case of any error.

Arduino UNO is an 8-bit microcontroller with the AVR architecture, and it offers different features and capabilities.

UNO comes with a total of 14 digital input-output (I/O) pins that you can use as input or output. Out of these 14 pins, you can use the six pins for producing PWM signals. Each pin on this board works at 5V and has a current of 20mA.

Arduino UNO

  • We always need a power source to make txhe board work. You can power this board using a USB connection to your computer, and you can either use a wall power supply that will terminate in a barrel jack. In the above image, (1) specifies the USB and (2) specifies the barrel jack. 

You can even load the code using a USB connection onto your Arduino board.

USB connection onto your Arduino board

The above image shows the following:

  • GND (3): GND stands for ‘Ground,” which is used to ground your circuit.
  • 5V (4) & 3.3V (5): The 5V pin can be used to supply five volts of power, and the 3.3V pin can be used to supply 3.3 volts of power. 
  • Analog (6): These pins labeled from (A0 to A5) are known as Analog pins. They will convert an analog sensor to a digital one.

The top right of the above image highlights the 14 I/O pins that can perform specific functions, as stated below:

  • With pins 0 and 1, you can carry out serial communication to receive and transmit serial data. You can use them to program the Arduino board and communicate with a user via the serial monitor.


  • With pins 2 and 3, you can provide external interrupts. These pins trigger an external event.
  • Six pins (3-11) are used for 8-bit PWM output.


  • Pins 10, 11, 12, and 13 are for SS, MOSI, MISO, and SCK, respectively, especially for SPI communication.


  • Pin 13 comes with a built-in LED connection. When this pin is set to HIGH, the LED is turned on, and when it is LOW, the LED is turned off.


  • AREF stands for Analog Reference, used to set an external reference voltage ( 0 -5 Volts).


  • At the top left of the above image, (10) specifies the reset button. This button connects the reset pin to the ground and restarts the uploaded code. Pressing the reset button in case of failure will allow you to test your code multiple times. 


  • The number (11) specifies the Power LED Indicator, which will light up when powering your Arduino to a source. 

  • In the above image, (12) specifies the TX RX LEDs, where TX stands for transmit and RX for receive. These are used for serial communication. These LEDs provide visual indications while receiving or transmitting data using Arduino.


  • (13) specifies the Integrated circuit, otherwise known as the brain of Arduino. You can see the IC type mentioned on the top of the IC. 


  • (14) specifies the voltage regulator, which helps control the amount of voltage supplied to the Arduino board. It acts as a gatekeeper, preventing an extra voltage from entering the circuit. Also, it comes with some limits, so do not connect the Arduino to more than 20 volts.


Why Should You Use Arduino?

Today, many people use Arduino. It’s easy to use and program, thus making it more popular among beginners and advanced users. You can connect Arduino to multiple platforms such as Mac, Windows, and Linux. Moreover, you can use it to create low-cost scientific instruments. 

Arduino provides you with an opportunity to play around with microcontrollers. Below are some significant reasons to use Arduino.

  • Cheap: Arduino boards are affordable. If you know, you can even assemble Arduino by hand or use the pre-assembled Arduino modules that cost less than $50.


  • Cross-platform: You can plug your Arduino board on any platform such as Windows, Mac, and Linux operating systems. 


  • Simple programming environment: The Arduino Software’s IDE is simple and easy to learn, as it comes with a simple version of C++.

Constraints of Arduino

Despite various reasons to use Arduino, you need to understand its limitations before working with it.

  • Memory: Arduino does not have enough memory for storing programs and variables. Also, you cannot add external memory to it. ATmega32 and ATmega128 can be used for external memory, but you cannot utilize the I/O functions for those pins. 

Arduino boards cannot accommodate external memory because of their basic design assumptions. It is important to remember that Arduino is an inexpensive Intel-based single-board computer and was not designed to replace a full-on computer system with high system requirements.

  • Speed: The Arduino CPU clock rate is between 8 and 20 MHz — that is way slower than most platforms. You can execute several instructions in each clock cycle, and that’s a lot of available CPU activity to be handled in between each pulse.


  • Electrical power: When working with Arduino hardware, you need to consider voltage parameters since some devices have 3.3V I/O while others are 5V tolerant. If you connect a 5V transistor-transistor logic to a 3.3V device, it will impact the hardware and can harm your Arduino.


Applications of Arduino

The following are some typical applications of Arduino:

  • Robotics: Arduino is suitable for both entry- and intermediate-level robotics projects. You can give it basic commands to make a robot function, even with limited resources at hand. Some well-known examples of robots developed using Arduino are K’Nex Wall-Following Robot and SCARA Robot Arm.


  • Audio: From Hi-Fi to headphones, everything depends on sound quality. Unfortunately, Arduinos are not suitable for audio, but you can use them to add an audio element to your projects.


  • Tools: You can design devices like print farms, 3D printers, CNC machines, laser etchers, etc., using Arduino. 


  • Networking: Most Arduinos offer built-in networking capabilities, usually in the form of an Ethernet port. You can utilize this facility in various projects, such as IoT and data-logging projects.


  • GPS: You can use Arduino to track devices and vehicles and create one of the most impressive applications involving GPS.

Well, there is no limit to its application, but we have only mentioned a few. 


What is Arduino? It's your first step in developing creative new applications and electronic projects. That sums up the basics of Arduino. Whether you're a beginner or experienced circuit designer, opt for Arduino to create unique applications with this easy-to-install program. You can download Arduino IDE for coding and start working on your versions of Arduino, as it is available freely and is open-source. 

If you are passionate enough to create new and valuable applications, then Arduino is your way to go. To learn more, check out our list of the Best Arduino Courses to Learn in 2024.

Learn more about Arduino:


By Aakash Yadav

Aakash is a computer science professional with experience in hoisting many startups with his skillset. Over the course of his career, he has achieved expertise in IoT (Internet of Things), Machine Learning and full-stack software, apps and website development by working on many successful products. Being a constant learner himself, he knows the struggle of finding precise and high-quality content on the Internet and with his courses, he hopes to eliminate this hassle for other newcomers.

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