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What is Arduino?

Updated: Aug 11, 2023

We all have used the #Arduino board for projects, haven't we? The solution to all the mini-projects and the automated devices that we build as students is Arduino. We are thrilled when we write the first code in Arduino IDE, interface the circuit, and built a Robot. It's time to know what Arduino is and what is on the board along with their functions.

Arduino Board
Arduino Board

Let's get started with the description of Arduino as a platform or IDE first.

What is the Arduino IDE?

IDE Logo
IDE Logo

Arduino is an Integrated Development Environment (IDE) which is a cross-platform application that can be run on different Operating Systems (#Windows, #Linux, #macOS). The program code is written in C and C++ programming languages. The code is written can be interfaced with different boards based on its compatibility. The code is interfaced with the hardware from the system by connecting it through a USB cable.

IDE Window
Arduino IDE

The #IDE contains several Libraries (header files) that can be included so that different microcontroller boards can be interfaced and worked upon. The code mainly contains two elementary functions inside which the user can define the necessary variables, functions, etc. required to run the code and work on the hardware interfaced. They are "void setup( )" and "void loop( )". The global variables and header files can be defined and included outside these functions as usual.

What is an Arduino board?

Arduino Uno Board
Arduino Uno Board

The first and basic necessity for the Arduino or any board to work is the Power supply. The power to the Arduino board can be supplied in two ways.

  • Through USB

The USB cable is used to connect the system and the Arduino Board USB port. Power will be supplied to the board through the system itself and interfacing of hardware and software will happen.

  • Through DC connection

The port parallelly present on the board next to the USB port is the DC input port. The input range is 7-12V. This port is also called a barrel jack through which DC power can be supplied directly from the wall supply.

  • Ground pin(GND)

The Arduino Board contains more than one GND pins that can be connected to the ground of the circuit.

  • 5V pin

As the name of the pin goes, 5V power is supplied from the board

  • 3.3V pin

3.3V Power is supplied from the board through this pin. Any of the voltage supply pins can be used based on the necessity of the circuit.

  • Analog Pins

Pins numbered A0 to A5 are analog pins that provide digital values as the output even when they can read analog values from the sensors.

  • Digital pins

Digital pins can be used for both input and output to a device (values 0 or 1). The pins numbered 0 - 13 are digital pins.

  • PWM pins (Pulse Width Modulation)

In pulse width modulation, analog output can be simulated. The pins having a tilde symbol ( ~ ) next to the PINs are the PWM pins. The pins numbered 3, 5, 6, 9, 10, and 11 can be used as #PWM pins in Arduino Uno. These pins can be used to simulate analog outputs.

  • AREF pin

The Analog Reference pin is used to set the value limit for external reference voltage (0V - 5V). It is rarely used.

  • RESET button

This button is used to erase the stored or present values of input/output based on the code.

Pressing this button, the code can be run from the beginning.

  • Power LED

This LED is an onboard indicator of the proper functioning of the circuit. This LED usually glows when the device is interfaced and the code is checked and ready to execute. If the LED remains off, either the circuit, the code, or the board itself might be having a problem.

  • TX, RX

Transmitting and Receiving are shortly denoted by TX and RX respectively. These are LEDs that indicate when the information is being transmitted or received based on the circuit and the code. There are two sets of TX, RX pins. One set in line with the DIgital pins and the other set next to the TX, RX LEDs.

  • IC ( Integrated Circuit )

One of the biggest advantages of the Arduino board is that it has a Main #IC embedded on the board. An external connection to the IC is not required. There are various ICs with different functions. Each IC description and working can be known from their respective datasheets.

Arduino boards also differ based on the ICs as they are the Brain of the Arduino board. It is manufactured by the ATMEL company.

  • Voltage Regulator

When we design a circuit using components of our own, we use a resistor to limit the amount of current passing through the circuit and the components which are sensitive to protect the components from damage. A similar function is done by the voltage regulator, which keeps a limit over the voltage passed to the board and protects it from any damage. It is not used to interact with the board.

  • I/O reference

The input/output reference pin is rarely used. It is used when the circuit needs to have a limit or range of values for the input and output.

  • Vin

The voltage-in pin is used to supply a particular value of the input to the board.

  • ICSP

The set of pins or components embedded next to the IC are the In-Circuit Serial Programming pins. This method of communication is mostly used in #microcontrollers to send data to a particular memory area (Flash, RAM, etc.).

This completes the description of the on-board components.


  1. Arduino #UNO R3

Let us understand What is Arduino Uno?

Arduino UNO R3
Arduino UNO R3

This is the most basic and widely used configuration of the Arduino board. It contains all the pins and components as described above:

  • 14 input/output pins ( 6 PWM pins).

  • 6 Analog Input pins.

  • USB port.

  • Power jack.

  • Reset Button.

  • It has a flash memory of 32kB.

Buy Arduino UNO R3 from here.

2. Arduino Mega R3


#Mega board has a higher capacity than the UNO board in terms of the number of pins and the flash memory.

  • 54 digital input/output pins ( 14 PWM pins ).

  • 16 analog inputs.

  • USB port.

  • Power jack.

  • Reset Button.

  • Flash memory: 256kB.

  • Wider application compared to the UNO board as more LEDs or components can be connected at once.

Buy Arduino Mega R3 from here.

3. Arduino Leonardo


This board is different from the latter ones as it contains a microcontroller with a built-in USB. The libraries which used to include the defined functions are available with it. This allows emulating the keyboard, mouse, and other components.

Buy Arduino Leonardo from here.

4. Lilypad Arduino


The #Lilypad board is particularly designed to be used in the e-textile industry. This microcontroller board can be sewn into clothes and wearables. IT is connected using a conductive thread.

What can be used along with Arduino Boards?


Sensors compatible with Arduino
Sensors compatible with Arduino

The implementation of the Arduino board is mainly done with a wide range of sensors. A few examples are Ultrasonic Sensors, Temperature sensors, Flame sensors, etc and the list goes on.

Click here to buy a Combo of sensors.


Sheilds compatible with Arduino
Sheilds compatible with Arduino

Shields are hardware devices that are used/connected additionally with the Arduino board. They are pre-built circuit boards that provide extra capabilities to the Arduino. Few examples of #shields are Relay shield, Motor shield, LCD shield, etc.

Robot using Arduino
Robot using Arduino

The application of Arduino is vast and we get to explore only when we built a circuit, collect different components, and code it ourselves. Now that we know the components, working, and functions of Arduino, let start designing circuits and building devices.

Buy different shields for Arduino by visiting the links for each shield.



Check this Arduino Projects listed below:

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2 commenti

Anushka Gupta
Anushka Gupta
27 lug 2023

I'm thoroughly impressed with the clarity and coherence of this article. Learn Electronics India has managed to present complex technical information without any jargon overload. The practical insights and real-world examples are incredibly valuable, making it easier for enthusiasts like me to get started with Arduino. Thank you for sharing your knowledge with us!

Mi piace

LearnElectronics India simplifies complex concepts beautifully. Thank you!

Mi piace
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