CHAPTER
3

Required Accessories

In This Chapter

To keep the cost of the Raspberry Pi so low, you have to do a bit of work and accessorizing to get it up and running. You don’t get everything you need in the box, for example, so you have to find the additional components you need on your own. For people who like to customize their computers, this is great. If you’re not one of those people, don’t worry. In this chapter, you learn what accessories you need to work with your Raspberry Pi.

To start, you’ll need a power supply, an SD card for storage, and a few other cables to get your Raspberry Pi hooked up to a screen and to the internet. Chances are, you probably have most of this stuff already, and even if you don’t, many of these parts are inexpensive. The Raspberry Pi is made to be as affordable as possible, so that means it has universal plugs and a wide range of support for accessories.

With that in mind, let’s go through the list of what you need to get your Raspberry Pi outfitted.

Powering Your Raspberry Pi

The Raspberry Pi uses a 5-volt micro USB power supply. This is similar to what you get with a mobile phone. Each version of the Raspberry Pi needs a different amount of power, but you can generally use the same power adapter for each model. Power adapters are tricky business, so you’ll want to be sure you get the right one.

Amperage and Voltage Requirements

The power adapter requirements for the Raspberry Pi are surprisingly confusing, but thankfully, you only need to know a few different numbers.

The Raspberry Pi requires a 5-volt (5V) power adapter that connects with a micro USB. A ton of different mobile devices already come with these kinds of power adapters, including Kindles, Android phones, and many other devices. If you look at a power adapter, you’ll usually see the voltage listed on the adapter itself.

You’ll need a power supply with an amperage rating of at least 1.2 amps for Models A+ and B, and 2.5 amps for Models B+ and 2. The number is the amperage you need to provide enough juice to the Raspberry Pi. Amps (often abbreviated A) are the current that supply power to your device. You can go over in amps, but you can’t be under. Models B+ and 2 have more USB ports, so they need more power to send to the accessories you connect.

DEFINITION

Amperage is the amount of ampere (usually shortened to amp or abbreviated A), which is the unit used to measure electric current. For power adapters, it’s used to gauge the maximum number of power the adapter can send from an outlet to the device. If it’s too high, the power adapter will adjust downward to avoid overloading the device, but if it’s too low, the device simply won’t power on.

If this all sounds confusing, don’t worry. Purchasing a Raspberry Pi power supply is really easy.

Finding a Power Adapter

When shopping for a power supply for your Raspberry Pi, look for something that will work with the model you have. If you have a Model A+ or B, look for a 5V micro USB power supply with a current rating of 1.2A. If you have a Model B+ or 2, you want a 5V micro USB power supply with a current rating of 2.5A. Typically, you can search for these online and find what you need, but you can also take a look at any power adapters you already have around the house.

Look at a power adapter, and you’ll find a lot of different numbers and symbols. Most of them don’t matter to you right now. What you want to look for is the output voltage (that’s the 5V) and the current in amps (that’s the 1.2A or 2.5A). If you have a power adapter that meets those ratings and connects to a micro USB cord, you can use it with your Raspberry Pi.

Otherwise, you need to find a power adapter in a store or online. The Raspberry Pi doesn’t have an official power adapter, so any adapter you find that meets the voltage and amperage requirements should work.

SD Cards

Unlike a traditional computer, the Raspberry Pi doesn’t have a hard drive of any kind. Instead, it uses an SD card, like you find in digital cameras, for all its storage. You’ll eventually install your operating system on the SD card (or micro SD in the case of Models B+, A+, and 2), and you’ll keep all your files there as well. This might sound like a hassle, but it’s actually an advantage.

The “Hard Drive” for Your Pi

On the Raspberry Pi, the SD card works just like a hard drive on your laptop or desktop computer. You install your operating system onto it, you store your files on it, and you can use it just like you would a regular hard drive.

This ends up being pretty handy because chances are, you’ll want to experiment with a lot of different projects on the Raspberry Pi. SD cards are rather inexpensive, so it’s easy to just swap them for different projects instead of switching to a different Raspberry Pi.

Recommended SD Cards

For the most part, almost any SD card will work as long as it’s listed as a class 4, but it’s recommended you get one with at least 8 gigabytes (GB) of storage. This gives you enough space to install the operating system and any additional programs you need.

Almost any SD card should work with the Raspberry Pi, but some exceptions exist. The eLinux page has a breakdown of every SD card tested with the Raspberry Pi at elinux.org/RPi_SD_cards. Before you order an SD card, check this list to be sure the one you’re looking at will work.

The same goes for Models A+, B+, and 2, but you’ll need a micro SD card instead of a standard-size SD card.

PI POINTER

You have a lot of operating system options on the Raspberry Pi. The nice thing about using SD cards to hold your operating system is that you can swap operating systems and setups as often as you like, just by changing the SD card.

The Raspberry Pi is equipped with both HDMI and composite ports for video output.

Composite and HDMI Options

What you’re connecting to your Raspberry Pi dictates which type of video output you use. If you’re connecting an older TV, you’re probably going to be stuck with a composite cable—the yellow cable used with pre-HD televisions. If you’re using an HD TV or a newer PC monitor, you’ll probably use HDMI.

On whatever screen you’re connecting your Raspberry Pi to, you’ll find either a composite or HDMI input, or both. HDMI is the flat connector found in most modern screens that outputs both audio and video in one signal. The composite video input is almost always yellow, and all you’ll need is a RCA cord to connect it.

On Models A+, B+, and 2, the RCA composite jack has been replaced with a 3.5mm RCA jack, which outputs both audio and video, but to use it, you’ll need a 3.5mm-to-3 RCA adapter cable, similar to the cables you’d use with a camcorder. The HDMI port is flat and a bit square, and you’ll need a HDMI cable to use it.

HARDWARE HELPER

If you want to output in HD to a widescreen television or monitor, pick up an HDMI cable. With it, you can easily hook up your Raspberry Pi to just about any modern screen.

For the most part, it doesn’t really matter what brand of cable you use for your Raspberry Pi. Any HDMI or RCA composite cable will work; just be sure it’s long enough for your needs.

Connecting to PC Monitors Versus HD TVs

You can use either a PC monitor or an HD television with your Raspberry Pi if you want an HD signal. The Raspberry Pi doesn’t support VGA (video graphics array), so if you still have an old monitor left over from the 1990s, it won’t work.

Choosing between a PC monitor and an HD television is really about your planned usage. If you plan on using your Raspberry Pi to watch movies, play games, or do any other multimedia activities, an HD television is probably the best option. If you plan on using it as an actual computer and will be typing on it a lot, you might be better off with a small PC monitor.

Sound Output

The Raspberry Pi has two different sound outputs: HDMI audio and the 3.5mm audio jack. Which option is best is partially based on which model of Raspberry Pi you have and what you plan on doing with it.

Like HDMI video, the HDMI audio signal is a crisp HD signal, and using the HDMI cable means you’ll get high-quality sound from your Raspberry Pi. It only works through the HDMI cable, so you’ll likely be running your audio through your computer monitor or television.

Your other option is to send your audio through the 3.5mm stereo audio jack. This is the jack on your Raspberry Pi that looks similar to the headphone jack you’ll find on a smartphone. Model B outputs a grainy signal through the stereo jack, so it’s not recommended for use if you really care about your audio quality. Models A+, B+, and 2 improved on this though, and the audio quality is a lot better.

The Raspberry Pi has two options for audio output: an HDMI audio/video port and a 3.5mm audio jack.

HARDWARE HELPER

If your computer monitor doesn’t support HDMI, you can use a DVI-to-HDMI cable to hook up your Raspberry Pi to it. These cables usually cost around $5 and enable you to easily connect your Raspberry Pi to older monitors.

Connecting to the Internet

Finally, the last key accessory and connection you’ll need to get your Raspberry Pi up and running is an internet connection. You can connect to the internet by either the built-in Ethernet adapter or by installing your own Wi-Fi adapter through a USB connection.

Nearly every project in this book requires an internet connection from either your personal computer or the Raspberry Pi itself. If you don’t have one, it’s still possible to use the Raspberry Pi, but it’s considerably more difficult.

On-Board Ethernet

Out of the box, you’ll likely want to connect your Raspberry Pi to the internet through the Ethernet port. You can then connect your Raspberry Pi directly to a modem or a router.

Wi-Fi Adapters

If you’d prefer your Raspberry Pi be a bit more mobile than wired Ethernet allows, you can connect it to a USB Wi-Fi adapter.

You can use the Raspberry Pi’s Ethernet or USB ports to get online.

However, you’ll need to download some drivers and run a few setup procedures before you do that, so Ethernet is recommended for at least the first portion of the setup process. Don’t worry if this sounds complicated. I walk you through setting up Wi-Fi in Chapter 11.

The Least You Need to Know