Arduino Beginner Series: A tour of the Arduino UNO board

Welcome to another post on the Arduino. In this post we’ll discuss the main components of the Arduino UNO board (since that’s the board we’ll work on for the projects coming up!). I would Love to hear from you guys so be sure to post your doubts, queries and experience about this post in the comments!

The Arduino UNO Board

The Arduino is the perfect place for beginners to start out in the electronics field. The Arduino UNO board is the easiest one to deal with and I strongly recommend you guys to use it if you are starting out. We’ll work with other boards a little later.

So let’s get on with this tour!
You really don’t need to dig into the details of each component so this is just a brief beginners point of view.
Here’s a list of the major components of the Arduino UNO board:

  1. USB connector
  2. Power Port
  3. Microcontroller
  4. Digital Pins
  5. Analog Input Pins
  6. Reset Switch
  7. Crystal Oscillator
  8. USB Interface Chip
  9. TX-RX Leds

1. USB Connector

This port is used to to both power the arduino board and load the code from the Arduino IDE to the board.

2. Power Port

This port is also used to power up the Arduino. This port is used when we can’t keep the Arduino connected to our computer with the USB. For instance if you need to put the Arduino in some device or project. The port can be connected to a battery pack as shown in the above image.

3. Microcontroller- The brain of the Arduino UNO

The Arduino has an Atmega 328P microcontroller on board. It can be thought of as the brain of the Arduino. It holds the capacity to carry out basic computational functions. Microcontrollers are like a blank slate – no operating system working and they do only the code that you upload and are therefore able to do things more quickly and efficiently. The good thing about the Arduino Uno is that you can remove and replace the microcontroller on the board in case it gets damaged.

4. Digital Pins

The digital pins can be used as both input and output. When these pins are used for ouput, they also act as power supply for the component connected to it. When used as input they read the signals fed to them by various sensors and other electrical components. The swigly (~tilde) symbol next to some of the pin numbers are used for giving out analog outputs (they are used for pulse width modulation which we’ll learn about a little later).

5. Analog Input Pins

The Arduino UNO board has onboard 6 channel analog-to-digital (A/D) converters. While the main function of the analog pins for most Arduino users is to read analog sensors, the analog pins also have all the functionality of general purpose input/output (GPIO) pins (the same as digital pins 0 – 13).

6. Reset Button

This button sends a signal to the microcontroller to stop execution of the program and run it right from the beginning. Or you could use it if you want to test out your project multiple times.

7. Crystal Oscillator

So we humans turn to a clock as a time reference. Similarly, the microcontroller looks to the crystal oscillator. An oscillator is a circuit which produces a continuous, repeated, alternating waveform. The Arduino UNO has a 16MHz crystal oscillator (which clocks in at 16 million times per second). On each click an operation is performed by the microcontroller.

8. USB Interface Chip

This is another Atmega chip and it basically functions like a translator. It converts the signals recieved in from the USB port to what the microcontroller understands.

9. TX- RX LEDs

So Tx stands for Transmission and this lights up when the Arduino is transmitting a signal to another component. RX stands for Recieve and this LED lights up when the Arduino is recieveing signals from other components.


  1. wikipedia
  3. images: Google

Soo that’s all for this post!
Stay Tuned for upcoming posts on Arduino Projects! We’ll start with basic newbie projects and then move on to those cool, ultra techy projects!! Want to be the first to know when a new and amazing post comes up?? Then feel free to subscribe!

Leave a Reply


Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

search previous next tag category expand menu location phone mail time cart zoom edit close