Introduction

This chapter introduces the Raspberry Pi and the process to set it up for the first time. We will connect the Raspberry Pi to a suitable display, power, and peripherals. We shall install an operating system on an SD card. This is required for the system to boot. Next, we will ensure that we can connect successfully to the Internet through a local network.

Finally, we will make use of the network to provide ways to remotely connect to and/or control the Raspberry Pi from other computers and devices as well as to ensure that the system is kept up to date.

Once you have completed the steps within this chapter, your Raspberry Pi will be ready for you to use for programming. If you already have your Raspberry Pi set up and running, ensure that you take a look through the following sections as there are many helpful tips.

Introducing the Raspberry Pi

The Raspberry Pi is a single-board computer created by the Raspberry Pi Foundation, a charity formed with the primary purpose of reintroducing low-level computer skills to children in the UK. The aim was to rekindle the microcomputer revolution from the 1980s, which produced a whole generation of skilled programmers.

Even before the computer was released at the end of February 2012, it was clear that the Raspberry Pi had gained a huge following worldwide and has now sold over 2 million units. The following image represents a Raspberry Pi Model B:

A Raspberry Pi Model B (revision 2.0)

What is with the name?

The name, Raspberry Pi, was the combination of the desire to create an alternative fruit-based computer (such as Apple, BlackBerry, and Apricot) and a nod to the original concept of a simple computer that can be programmed using Python (shortened to Pi).

Within this book, we will take this little computer, find out how to set it up, and then explore its capabilities chapter by chapter using the Python programming language.

Why Python?

It is often asked, "Why has Python been selected as the language to use on the Raspberry Pi?". The fact is that Python is just one of the many programming languages that can be used on the Raspberry Pi.

There are many programming languages that you can choose, from high-level graphical block programming, such as Scratch, to traditional C, right down to BASIC, and even raw Machine Code Assembler. A good programmer often has to be code multilingual to be able to play to the strengths and weaknesses of each language in order to best meet the needs of their desired application. It is useful to understand how different languages (and programming techniques) try to overcome the challenge of converting "what you want" into "what you get" as this is what you are trying to do as well while you program.

Python has been selected as a good place to start when learning about programming by providing a rich set of coding tools while still allowing simple programs to be written without fuss. This allows beginners to gradually be introduced to the concepts and methods on which modern programming languages are based without requiring them to know it all from the start. It is very modular with lots of additional libraries that can be imported to quickly extend the functionality. You will find that over time, this encourages you to do the same, and you will want to create your own modules that you can plug in to your own programs, thus taking your first steps into structured programming.

Like all programming languages, Python isn't perfect; things such as adding a space at the start of a line will often break your code (indents matter a lot in Python; they define how blocks of code are grouped together). Generally, Python is slow; since it is interpreted, it takes time to create a module while it is running the program. This can be a problem if you need to respond to time critical events. However, you can precompile Python or use modules written in other languages to overcome this. It hides the detail; this is both an advantage and disadvantage. It is excellent for beginners but can be difficult when you have to second-guess aspects such as data-types, but this in turn forces you to consider all the possibilities, which can be a good thing.

Python 2 and Python 3

A massive source of confusion for beginners is that there are two versions of Python on the Raspberry Pi (Version 2.7 and Version 3.2), which are not compatible with one another, so code written for Python 2.7 may not run with Python 3.2 (and vice versa).

The Python Software Foundation is continuously working to improve and move forward with the language, which sometimes means they have to sacrifice backward compatibility in order to embrace new improvements (and importantly, remove redundant and legacy ways of doing things).

Note

Supporting both Python 2 or Python 3

There are many tools that will ease the transition from Python 2 to Python 3, including converters such as 2to3, which will parse and update your code to use Python 3 methods. This process is not perfect, and in some cases, you'll need to manually rewrite sections and fully retest everything. You can write the code and libraries that will support both. The import __future__ statement allows you to import the friendly methods of Python 3 and run them using Python 2.7.

Which version of Python should you use?

Essentially, the selection of which version to use will depend on what you intend to do. For instance, you may require Python 2.7 libraries, which are not yet available for Python 3.2. Python 3 has been available since 2008, so these tend to be older or larger libraries that have not been translated. In many cases, there are new alternatives to legacy libraries; however, their support can vary.

In this book, we have used Python 3.2, which is also compatible with Python 3.3.