2.1 What is an Arduino
An Arduino is an Open Source small computer that you can program to process its input and output pins. It was originally designed for students without a background in electronics and programming. Through the use of hardware and software, one can use the Arduino to interact with the environment. An example is to have a temperature sensor connected to Arduino so as to measure the ambient temperature. You can as well have both the sensor and an actuator connected to the Arduino. Where by the sensor measures the state of the environment while the actuator is used to perform the control function based on the measurements obtained from the sensor.
Since the Arduino board is cheap and readily available in almost all parts of the world, it has revolutionized the world in a number of ways. Firstly, it has become the best learning tool for those who wants to learn software and hardware development at the same time. Secondly, Arduino has gain a lot of popularity amongst the Do It Yourself (DIY) hobbyist and you can see the wonders they have done with it all over the internet. Lastly, there are infinite number of automatic vending machines out there whose backbone is the Arduino board. As a result, a number of companies and individuals have benefitted much in gainful employment and income earning opportunities.
The Arduino board is made of a microcontroller which forms the heart of the board. It also has a crystal oscillator which basically acts as a clock that sends time pulses to the microcontroller to enable it to operate at the correct speed. The board also has digital and analog Input and Output pins to enable one to connect the microcontroller pins to other components such as LEDs, sensors, shields and modules.
The Arduino Integrated Development Environment (IDE) is used to write a computer program that you can then upload to the Arduino. Once the code is uploaded to the Arduino, it will carry out the instructions in the code and enables the Arduino interact with the outside world.
2.2 Types of Arduino Boards
There are many kinds of Arduino boards but the most common ones are;
- Uno
- Mega
- Leonardo
- Nano
- Due
Fig. 2. 1 Types of Arduino boards
The Arduino Uno board offers the best option for the beginners in the Arduino world. It consists of 14-digital pins and 6-analog pins. The digital pins can be used as both the input/output (I/O) pins to the Arduino while the analog pins as input pins.

Fig. 2. 2 Architecture of the Arduino Uno Board
You now know what an Arduino is and what it can do. In the next topic we will get started with the Arduino. This will involve downloading and setting up the Arduino IDE for uploading the codes (Arduino Sketches). We will then use the Arduino in a number of projects.