The Arduino platform is a hardware board that offers a hardware-software integrated creative device development platform. The Arduino boards can be interfaced with openly available peripheral devices and custom programs can be written and loaded (embedded) into the Arduino development board:
These programs in turn control and interact with various peripheral components attached with the Arduino board. Thus by using the Arduino development boards; device designers and engineers can quickly create a running prototype of their imaginations. The best part is that the Arduino hardware and software eco-system is open source.
There are many different types of Arduino boards available in the market. Depending upon the processor speed, number of general purpose input/output pins and different power supply options there are many types of the Arduino boards. These boards are chosen depending on a project's needs.. The most commonly used and recommended Arduino board for the purpose of learning is the Arduino Uno board.
Usually Arduino Uno boards have an ATmega328P microcontroller and surrounding the microcontroller there are several General Purpose Input Output (GPIO) pins into which male jumper wires can be plugged in for connecting to peripheral devices.
The ATmega328P microcontroller is used as the brain of the Arduino Uno board. It is an 8 bit 5 volt Reduced Instruction Set (RISC) based single chip microcontroller. The ATmega328P microcontroller is also referred to as an AVR microcontroller which is a family of microcontrollers developed by Atmel. Atmel is a popular micro controller manufacturer.
Apart from the GPIO pins, you will notice several electronic components on the board such as a voltage regulator and some Integrated Circuits (ICs) to name a few. You will also notice a distinct USB B port and a DC IN power socket.
Let us get to know the Arduino Uno board and its components a little better, so that we are aware of what goes where during the course of this book. For a detailed list of components, the Arduino Foundation website is always recommended for further reading on latest updates.
A list of the major components has been provided in the next table for quick and easy reference. The following description should suffice for getting started on the Arduino platform and also for the scope of this book. Throughout your prototyping journey, you will find this reference very handy and useful.
| Arduino component(s) | Component usage |
| ATmega328P microcontroller | The microcontroller executes the embedded programs. |
| Digital I/O pins | There are a total of 14 digital I/O pins numbered from 0 to 13. Out of the 14 pins six pins provide Pulse Width Modulation (PWM) output. These pins help in providing a connection with various peripheral components. While creating device prototypes we will frequently plug in male jumper cables into the female I/O pins of the Arduino board. |
| Analog I/O pins | There are six analog input pins, numbered from A0 to A5. These pins are also used for connecting various peripheral components. |
| Interrupt pins | Digital pins 2 and 3 provide a mechanism to receive interrupt signals from peripheral devices. |
| Power supply pin (input) | Vin, this pin can be used to receive power from external DC supply in the range of 5 - 12 volts. |
|
Power pin (5V output) |
5V, this pin provides an output of 5V regulated DC supply, for peripheral devices that run on 5 volts. |
|
Power pin (3.3V output) |
3.3V, this pin provides an output of 3.3V regulated DC supply, for powering peripheral devices that run on 3.3 volts. |
|
Power pin (Ground) |
GND, there are three ground pins on the board. These pins are used to plug in the common grounding jumper wires, in order to obtain a common ground reference for all the peripheral components connected to the Arduino board. |
| Flash memory | The ATmega328P microcontroller has 32 KB of flash memory. The embedded C programs are loaded into this memory area. |
| USB B port | This port is used to connect with and power up the Arduino board from a computer USB A port. |
| DC IN jack | This port is for receiving DC power from various DC power sources. |