If we search for the term Raspberry Pi over the web or open the Raspberry Pi Foundation's webpage, we will find that the Raspberry Pi is a computer that is the size of a credit card.
Parts of a Raspberry Pi
The Raspberry Pi Foundation (http://www.raspberrypi.org/) initially released the Raspberry Pi model B. This was followed by the Raspberry Pi model A. In 2014, the Raspberry Pi foundation released variants B+ and A+. The Raspberry Pi models A and A+ (costing 25 USD and 20 USD respectively) do not come with an Ethernet port, a USB port and 256 MB RAM. The model A+ replaced model A while the model B+ replaced model B. The model B (price: 35 USD) came with an Ethernet port, 2 USB ports, and 512 MB RAM; model B+, which supersedes model B, comes with 40 pin GPIO header as opposed to 26 in the earlier models, and has 4 USB ports and a micro SD card slot instead of the SD slot. Per the Raspberry Pi Foundation website, model B+ (as well as model A+) consumes lower power, has better audio and a better form factor, which we certainly concur with. The model A+ also comes with a 40 pin GPIO header and a micro SD card slot. The models A+ and B+ have nine more GPIO pins than their predecessors.
Note
The Raspberry Pi 2 was released after we finished writing the book. Please refer to the book's site to find out more about getting started with model 2.
The objective of this book is to build cool projects using the Raspberry Pi. We will discuss the components of Raspberry Pi from this perspective. If you are interested in finding out more about the Raspberry Pi, the Raspberry Pi Foundation's webpage has published the technical specifications of all the components.
First, we will discuss the components available on the Raspberry Pi and the use of these components in our projects. The components of the Raspberry Pi include:
2 USB ports (1 USB port available in model A)
Ethernet port (available only in models B and B+)
RCA output
HDMI output
Audio output
Low level peripherals, which include:
GPIO (General Purpose Input Output)
UART/Serial Port (Universal Asynchronous Receiver Transmitter)
I2C (two wire interface)
SPI (Serial Peripheral Interface)