Arduino UNO: A Short Review
What is Arduino?
Arduino is an open-source platform used for building electronics projects. Arduino consists of both a physical programmable circuit board (often referred to as a microcontroller) and a piece of software, or IDE (Integrated Development Environment) that runs on your computer, used to write and upload computer code to the physical board.
There are different kinds of Arduino boards. Such as Arduino Uno, Arduino Leonardo, and A-Star 32U4 Prime, Arduino mega R3, Lilypad Arduino microcontrollers. Arduino UNO is available almost everywhere and can do the work fine. So, let’s have some discussion about Arduino UNO!

What is Arduino UNO?
The Arduino Uno is a microcontroller board based on a removable, dual-inline-package (DIP) ATmega328 microcontroller. ‘UNO’ name comes from Italian language, it means one. The Uno board is the first in a series of USB Arduino boards, and the reference model for the Arduino platform.
There are many types and versions of Arduino UNO. The UNO R3 is the third, and latest, revision of the Arduino Uno.
Components of Arduino UNO:
The UNO has 20 digital input/output pins (I/O pins), of which 6 can be used as PWM outputs and 6 can be used as analog inputs. It has two 16 MHz crystal oscillator, edge connector having digital and analog pins for input/output connections, a USB connection, a power jack, an in-circuit system programming (ICSP) header, and a reset button.
There are 5V and 3.3V built in sources and ground pins in the UNO board. The edge connectors are divided into three categories or ports such as PORTB, PORTC and PORTD. PORTB has 6 I/O pins, PORTC has 6 I/O pins that are analog pins, PORTD has 8 I/O pins.
Two built in LEDs are present in the board, one is ON LED and the other is connected with Digital Pin 13(pin 5 of PORTB).
There is also am ADC (AC to DC converter) and a voltage regulator for regulating the voltage.
A microcontroller is a small and low-cost microcomputer, which is designed to perform the specific tasks of embedded systems like displaying microwave’s information, receiving remote signals, etc. Arduino UNO board has two microcontroller ICs. The longer bottom right IC is the ATmega328P microcontroller and the smaller square shaped IC is the ATmega16U2 microcontroller.


The flash memory of 328P MCU is 32KB that is very small. That’s why MCU 16U2 is used in the board. It is used for another reason. In case of serial connection, 16U2 MCU interprets the USB protocol and creates such a protocol so that the 328P MCU can understand.
There are two ICSP for two microcontrollers. Here, ICSP is used to program the internal firmware directly.
The ATmega328 also has 2 KB of SRAM and 1 KB of EEPROM (which can be read and written with the EEPROM library).
What can you do with Arduino?



Arduino hardware and software were designed for everyone who wants to do some creative work or projects. Arduino can interact with buttons, LEDs, motors, switches, LCD displays, speakers, GPS units, cameras, the internet, and even your smart-phone or your TV! It can be used to make taxi meters, weighing machines, calculators, pre-paid electric energy meters, humidity meters and temperature meters to measure the temperature and in many more fields.
There are two I/O pins i.e., A4 and A5 that are used in transmission of data from one Arduino to another Arduino or sensor to Arduino and vice versa. The two pins are SDA and SCL. By these two pins you can form a bus to transmit serial data and serial clock.
Specially for the students, it can be very helpful to do the college and university projects. Again, for its low cost and being a lightweight MCU, Arduino UNO has a vast usage in both academic cases and industrial cases.
Working system:

The Arduino UNO board needs both hardware and software to work properly. For software, Arduino IDE is used to run the codes and upload to the board as the user desires. Arduino code is written in C++ with an addition of special methods and functions, because C++ code is more likely to understand for all. So, one who can write codes in C++, can operate with Arduino. There are also some examples to practice in the IDE software. So, it will help you to understand the interface. And, there are many libraries in the IDE that helps with different communication and in case of showing the output.
At first, the code should be compiled properly so that no errors are there, then the board has to be connected to the computer with the USB cable and then the code can be uploaded to the board with proper connection.
There are some output devices to visualize or see the expected outputs and watch for errors after executing the code in the board. Such devices are Serial monitor, LED lights, LCDs, seven segment displays etc. Among them, serial monitor is the simplest output indicating device.
One thing about Arduino UNO that are available in the market is that it operates at 5V and it can withstand up to 20V of input voltage. But it is not wise to apply more than 12V to the board. The recommended input voltage is 7V-12V. Again, If multiple devices are connected to the board and a large current is drawn, the polyfuse in the USB will break the connection. Therefore, it should be operated carefully.
Arduino can operate I2C communication and SUART to transfer important data, like temperature, any kind of numbers, letters and thus a chatting platform can be built, and this is a huge advantage for modern technology.
Quite a good baseline introduction, but please don’t try to explain technical concepts.
e.g “” If more than 500 mA is applied to the USB port, the fuse will automatically break the connection”” is complete nonsense.
I appreciate the intent, but please call out for technical proof-reading.
Arduino is avery useful ‘environment’ for rapid prototyping. For permanent or commercial exploitation of the hardware, users might step up to custom dedicated hardware.
We appreciate your valuable opinion.
In my knowledge, for the availabile Arduino UNO in the market (not customized ones), it is true that fuse is present for overcurrent protection on the USB ports and the connection breaks if more than 500mA current is drawn from the device.
I have removed the exact value and corrected the sentence since it brought contradiction. Thank you.