This book assumes that a Raspberry Pi Model B is used, with its two USB ports and network connection (shown in the preceding figure). Model A (with one USB port and no network connection) will also work, but a USB hub (described later) will be needed to allow both a keyboard and a mouse to be used at the same time.
Along with a Raspberry Pi computer, you will need the following peripherals. In order to keep costs down, the Raspberry Pi was designed to work with devices that people already owned; so you may find many of these components around your house already. Just make sure they're not in use before you take them!
Note
http://elinux.org/RPi_VerifiedPeripherals is a useful website for checking whether a particular device will work with the Raspberry Pi.
The Raspberry Pi requires a Micro-USB connection (shown in the following figure), which is capable of supplying at least 700 mA (or 0.7 A) at 5V. Power supplies that can provide 1000 mA and more are available (and will be more reliable), but your chosen supply must give exactly 5 V. Most standard mobile phone chargers are suitable, and have their capabilities written on them, so you can check. Do not attempt to power your Pi from a USB port of another computer or hub as they are often incapable of supplying the required current.
The operating system and all files are stored on a standard SD card (shown in the following figure), which you may find in a digital camera. You will need at least 4 GB of space (preferably 8 GB+). The Raspberry Pi Foundation sells very affordable 8 GB SD cards with the operating system preinstalled at http://swag.raspberrypi.org/. You will also need a way to write data to an SD card from another computer. Many computers have built-in SD writers, but it is possible to buy USB dongles which do the job too.
We will use a monitor or a television with HDMI or DVI input, and a video cable connected from the Pi's HDMI port to the screen's input, as shown in the following figures. It is possible to connect to an older VGA or composite screen, but this is more complicated (refer to the Verified Peripherals link at the start of this section).
An Internet connection is not essential, but is very useful as it allows you to work directly on the Pi. The easiest approach is to use a wired Ethernet connection. It is also possible to use a USB Wi-Fi dongle. You will need a powered USB hub to provide additional USB ports, as shown in the following images:
You may also like to put your Raspberry Pi in a case to protect it, though this is certainly not necessary. There are many different companies that make many different styles, so choose one that suits you, or you could even make your own from Lego or card!