Introduction to Arduino:

Arduino is a microcontroller-based platform that consists of open-source hardware, software, and programming tools. The concept of the Arduino ecosystem revolves around simplicity, making microcontrollers more accessible to the general public and great educational aids.

Arduino was created in 2003 by a group of academics at the Interaction Design Institute Ivrea in Italy. The platform was named after a bar in the same town where the academics met to discuss the project. One of the project's goals was to remove the barrier of entry for students who wanted to realize automation ideas but did not have enough resources to purchase expensive controllers or knowledge to build their printed circuit boards.

Arduino has found tremendous success as an educational tool, as many universities worldwide have adopted it as a way to introduce students to control automation. Furthermore, thanks to low costs, Arduino is also very popular among individuals who build projects for personal use or as a hobby. In the next article, we will look at some applications of Arduino and evaluate whether it has potential in industrial settings.

The Arduino ecosystem has several advantages over other microcontroller platforms and PLCs. First, Arduino is relatively inexpensive, with many modules priced at less than 50 USD. Second, it is open source, which means code and libraries are available to everybody free of charge. Last, it is cross-platform and compatible with Windows, macOS, and Linux. Almost all other microcontroller platforms are compatible with Windows only.

On the other hand, Arduino hardware, being microcontroller-based, is not as powerful as PLCs—even some low-cost PLCs available in the market. Also, Arduino is not known for being suited to work in harsh environments. These trends are shifting, however, as Arduino develops the Pro series of modules with hardware, software, and platforms suitable for more extreme industrial environments.

In the next sections, let us look at the components of the Arduino ecosystem.

The Hardware

Now that you know the origin of Arduino, it is essential to get yourself acquainted with the hardware that Arduino as a company offers. One of the main reasons for Arduino being so accessible and affordable across the globe is because all of the Arduino hardware is open-source. Being open-source has a plethora of advantages- anyone can access the design and build of the device and make improvements; anyone can use the same hardware design to create their product lineup. Since Arduino is open-source, it has its own devoted community that strives to help the core company develop and improve its hardware products. Another significant advantage of being open-source, especially in the case of hardware, is that local companies can create replicas of the products, making it more accessible and affordable to the local consumers as it avoids hefty customs and shipping charges. All of these advantages contribute to Arduino being so widespread, affordable and ever-improving.
It is necessary to know that Arduino doesn’t necessarily offer just one piece of hardware, it provides a range of boards, each of which caters to a different level of expertise and have different use-cases altogether. Arduino Uno is one of the most basic and popular boards that Arduino offers. This is because it features an ATMega328 microcontroller that is both cheap and powerful enough for most basic beginner-level projects. Once you’re familiar with Arduino IDE, you can move up to boards with more powerful and sophisticated chipsets like the MKR range which is concerned with IoT applications and inter compatibility, or the Nano range which as the name suggests is designed to keep the form factor as small as possible while packing most of the features and power of the full-sized boards.

Understanding the Hardware

Note: Since this guide is aimed at absolute beginners, this article is limited to getting started with Arduino Uno.

So you got yourself an Arduino Uno, and you’re ready to jump into the world of electronics and join the community of makers from around the world, but before you begin with programming and external circuitry through breadboards and whatnot, it is necessary to understand the layout and circuitry of your Arduino Uno.

Using the above image as a reference, the labeled components of the board respectively are-

USB: can be used for both power and communication with the IDE
Barrel Jack: used for power supply
Voltage Regulator: regulates and stabilizes the input and output voltages
Crystal Oscillator: keeps track of time and regulates processor frequency
Reset Pin: can be used to reset the Arduino Uno
3.3V pin: can be used as a 3.3V output
5V pin: can be used as a 5V output
GND pin: can be used to ground the circuit
Vin pin: can be used to supply power to the board
Analog pins(A0-A5): can be used to read analog signals to the board
Microcontroller(ATMega328): the processing and logical unit of the board
ICSP pin: a programming header on the board also called SPI
Power indicator LED: indicates the power status of the board
RX and TX LEDs: receive(RX) and transmit(TX) LEDs, blink when sending or receiving serial data respectively
Digital I/O pins: 14 pins capable of reading and outputting digital signals; 6 of these pins are also capable of PWM
AREF pins: can be used to set an external reference voltage as the upper limit for the analog pins
Reset button: can be used to reset the board

Getting started with the Arduino IDE

Now that you’re familiar with the hardware, its time to learn about the development environment using which you’re going to program your Uno. The Arduino IDE is the best place to start your journey in programming your Uno. To get started, visit this page and download the latest build of the Arduino IDE for your Mac or PC. Go ahead and install the IDE on your PC or Mac and open it.

As you open the IDE, you’ll be greeted by a window similar to the one shown in the above image. The text editor is where you’ll be writing your code; you’ll use the verify button to compile and debug the written program, the save button to save the program and the upload button to upload the program to the board. Before you click on the upload button, it is necessary to select your board, Uno in this case, from the tools menu in the Menu Bar. After you choose your appropriate board, make sure you specify the correct port on your PC or Mac that you’ve connected your Uno to, in the IDE.

Uploading your first program

In this example program, we’ll be blinking the inbuilt L LED located right above the RX and TX LEDs. The Arduino IDE includes many basic programs to help you get started with your Uno. For this example, we’ll be using the inbuilt ‘Blink’ program. To open this program, go to the Files menu in the Menu Bar; click on Examples; click on 01.Basics; select Blink. Now that you’ve opened the example program, its time to upload the program, to do this, click on the upload button and wait for the process to complete. If your Output Pane header turns amber and shows an error which reads “Serial Port COM’x’ not found”, you’ve not connected your board correctly or that you’ve not specified the correct port that your board is connected to in the IDE. When you advance and start writing your own programs, you might run into errors while compiling and uploading; this can be because of a syntax error in the program. After you’ve corrected the errors and uploaded the program, you’ll see that the inbuilt LED blinks, alternating between the ON and OFF state every second.

Congrats on uploading and executing your first piece of code on your Arduino Uno. You can now tinker with the program you just uploaded by changing the values of delay. This will change the pattern and the rate of blinking. Do keep in mind that the default unit of time in the Arduino IDE is milliseconds; also remember that you’ve to upload the program to the board after you’ve made changes in the values of delay to notice the changes in the rate and pattern of the blinking.

Moving Ahead

Now that you’re familiar with the IDE and the hardware on the board, you can move up to programs that require external actuators and sensors using the inbuilt example programs as a reference. After you’ve gained some expertise with the board, you can move on to create projects that inculcate your innovative and innovative ideas. Soon in your journey through electronics, you’ll realize that the Uno is not powerful enough or does not pack the features you require for your expert level programs, that is when you’ll have to consider upgrading your board to something from the MKR line or to more powerful lines like the Yun.

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Block diagram of Arduino Board?

Here is an overview of the whole Arduino board. Anybody who has worked on Arduino will know that is a small board consisting of multiple components like ICs, and USB which are interconnected to form a whole connection. Here is a list of all the components

Analog Reference pin
Digital Ground
Digital Pins 2-13
Digital Pins 0-1/Serial In/Out – TX/RX
Reset Button – S1
In-circuit Serial Programmer
ICSP pin
Analog In Pins 0-5
Power and Ground Pins
External Power Supply In (9-12VDC) – X1
Toggles External Power and USB Power- SV1
USB (universal serial bus)
Crystal Oscillator

Microcontrollers

The microcontroller used on the Arduino board is essentially used for controlling all major operations. The microcontroller is used to coordinate the input taken and execute the code written in a high-level language. This code is then implemented and relevant output is generated. The choice of microcontroller varies on the requirements of the project.

The microcontroller used in the Arduino shown above is ATmega328P manufactured by ATMEL Company and it is the most common choice. Here are some features of this microcontroller.

ATmega328P has 14 Digital I/O Pins. Out of the 14 pins, 6 provide PWM(pulse width modulation) output.
ATmega328P can have 6 (DIP) or 8 (SMD) Analog Input Pins.
The DC Current which is supplied to each I/O Pin is around 40 mA.
ATmega328P has a flash memory of 32 KB.
ATmega328P has a SRAM(Static Random-Access Memory) of 2 KB.
ATmega328P has EEPROM(Electrically Erasable Programmable Read-Only Memory) of 1 KB.

Communication Interface

To function optimally, the Arduino needs to communicate with external devices like computers, sensors, and LEDs. By adding a communication interface, we can ensure that Arduino can receive and transfer data to external devices and therefore generate the required output. Let’s understand the components that make up the Communication Interface of Arduino.

Serial Communication (UART): The UART is a protocol used by Arduino for serial communication with other devices. UART stands for Universal Asynchronous Receiver/Transmitter and is used for bit data transfer. The built-in hardware in Arduino aids it in this communication with other sensors, actuators, Rasperry pies, and other boards.
Inter-Integrated Circuit (I2C): This is another communication protocol that comes into the picture when we want multiple connections but with minimal wiring. The way it allows communication between multiple channels is using two wires known as the SDA – Serial Data Line and SCL – Serial Clock Line. Arduino is designed with pins that help the Arduino to connect with sensors and displays without any inconvenience.
Serial Peripheral Interface (SPI): The last serial communication protocol that is used when we need high speed for data transfer. The multiple lines used in this protocol help to connect the microcontroller to other devices. Unlike I2C, it uses different wires to coordinate different tasks like communication, clock controls, etc. This protocol is suitable for connecting Arduino with SD cards, display modules, and digital-to-analog converters (DACs).

Digital Pins

In general, digital pins are used for general purposes like taking input or generating output. The commands that are used for setting the modes of the pins are pinMode(), digitalRead(), and digitalWrite() commands.

digitalWrite() is used to turn the resistors in each pin ON or OFF which will assign a HIGH or LOW value to the pins. The maximum current that can flow in each pin is 40 mA. Here are some digital pins.

Serial: These pins are categorized into two types namely receive (RX) and transmit (TX) serial data. On the Arduino Diecimila, the two pins are usually numbered ‘0’ and ‘1’ when they perform the task of communication. They are also present at pin 12 where TX flashes the LED while data is sent and RX flashes when data is being received. Sometimes, they are used with an external TTL serial module (e.g. the Mini-USB Adapter).
External Interrupts: As the name suggests, external interrupts are used to trigger an interrupt when required. This interruption can be due to a rising or falling edge, or a change in value. Once an interrupt is called, the Arduino will come to a halt and begin working only when told. These pins are PIN ‘2’ and ‘3’ which are controlled using the attachInterrupt() function.
PWM: PWM stands for pulse width modulation. The pin numbers 3, 5, 6, 9, 10, and 11 are PWM pins. The analogWrite() function is used for generating an 8-bit output. So when a large output is to be received or transmitted, the 8-bit output is generated. On certain boards like ATmega8, these pins are limited and present at 9, 10, and 11.
SPI(serial peripheral interface): This is a synchronous serial data protocol generally used by microcontrollers. This is present at pin number 10 (SS), 11 (MOSI), 12 (MISO), and 13 (SCK) which are used by microcontrollers for communicating with different devices. The relationship can be understood as the output device acting as a slave to the master of the SPI bus.
LED: Present at pin number 13 in some Arduino, LED is often used for testing purposes. The LED glows when the pin is HIGH, and turns off when the pin is LOW. Sometimes it is also possible to connect some external LEDS by using breadboard and jumper wires.

Analog Pins

In general, the analog pins are used for general purposes like supporting 10-bit analog-to-digital conversion (ADC) which is performed using analog the Read() function. These analog inputs can also be used as digital pins: analog input 0 as digital pin 14 through analog input 5 as digital pin 19. Analog pins are particularly helpful since they can store 0-255 bits which is not possible using digital pins. This feature is not available on every Arduino board.

I2C(Inter-Integrated Circuit): These pins are present at numbers 4 (SDA) and 5 (SCL) and are used to perform I2C (TWI) communication. Note that we need to import the Wire library to use this protocol.

Power Pins

The power pins are used to supply the power needed for operating the Arduino. In case some external source like a jack is being used to drive the power then it can be connected to this PIN. The supply of power that each board can take varies from one design to another and it is necessary to know this range for the board that you are using. Some Arduinos don’t have the VIN pin since they only accept a regulated input, one such example is lililyPad

5V(Power Supply): This is the voltage that is used for driving components like the microcontroller on the board. This power can only come either from VIN or a source that can provide a regulated voltage of around 5V. Any voltage less than this will not turn the Arduino on.
GND: This is known as the Ground pin and is used to set a reference level as the ground. This is automatically considered to be at the potential 0V.

Other Pins

AREF: The analog reference pin is often used to set an upper limit to the voltage for analog pins. This is set using the analogReference() function.
Reset: This pin is used to reset the state of the microcontroller by setting all values to their default values. Once all the actions have been performed or some wrong program is executed then you might want to reset the Arduino so you can use this pin for that.

Crystal Oscillator

The crystal oscillator is a device on Arduino that deals with issues involving time. The Arduino calculates time using this oscillator only. If you observe, you will see the number ‘16.000H9H’ printed on top of the Arduino crystal. This indicates that the Arduino operates at a frequency of 16,000,000 Hertz pf. Crystal oscillators are very precise and accurate devices. For example, a crystal oscillator is also present on he Arduino to provide clock pulses to the microcontroller Atmega 328 and help it control all commands and order of execution.

Applications of Arduino

Arduino finds its applications in various fields due to their ability to perform different things. Let us see some of its applications:

Arduinos are used in 3D printing where they perform the task of selecting how the printing will be performed.
Arduinos are used for creating basic designs by makers, designers, hackers, and creators across the globe to create some great projects. Some of the projects are Laser Turret Midi Controller, Retro Gaming With an OLED Display, and Traffic Light Controller.
Arduinos are used by college students to understand programmable electronics and to explore their interest in programming.
Arduinos are used in the field of robotics for programming robots and adding basic features like sensing and responding to environmental conditions.
Arduino is used in IoT(Internet of Things) since it can collect information using sensors. The collected data is then processed and transmitted for developing various smart devices.

Vin: This is the Arduino board’s input voltage pin, which is used to provide power from an external source.
5V: This pin on the Arduino board is utilised to provide a regulated power supply voltage to the board as well as onboard components.
3.3V: This pin on the board is used to deliver a 3.3V supply that is generated by the board’s voltage regulator.
GND: The Arduino board is grounded using this pin on the board.
Reset: The microcontroller is reset using this pin on the PCB. It’s for resetting the microcontroller.
Analog Pins: The analogue input ranges from 0 to 5V and is used on pins A0 to A11.
Digital Pins: The Arduino board’s pins 4, 6, 8, 9, 10, and 12 are utilised as digital inputs or outputs.
External Interrupt Pins: This pin on the Arduino board is used to generate an external interrupt, and pin numbers 0, 1, 2, and 3 are utilised to do so.
PWM Pins: These pins on the board are used to change the width of the pulse to convert a digital signal to an analogue signal. PWM pins are three, five, six, nine, ten, eleven, and thirteen.
Serial pins: These are also referred to as UART pins. It allows the Arduino board to communicate with a computer or other devices. To broadcast and receive data, the transmitter pin number 1 and receiver pin number 0 are used, respectively.
I2C: The board’s I2C pin is utilised for communication.

Pin number 2 signifies Serial Data Line (SDA)and it is used for holding the data.
Pin number 3 signifies Serial Clock Line (SCL) and it is used for offering data synchronization among the devices.

SPI Pins: This is the Serial Peripheral Interface pin, it is used to maintainSPI communication with the help of the SPI library. SPI pins include:

SS: It is used as a Slave Select
MOSI: It is used as a Master Out Slave In
MISO: It is used as a Master In Slave Out
SCK: It is used as a Serial Clock

LED Pin: The board has an inbuilt LED using digital pin-13. The LED glows only when the digital pin becomes high.
AREF Pin: This pin on the Arduino board is an analogue reference pin. An external power supply is utilised to provide a reference voltage.

Jyoti Verma

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