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Chapter 1
The Raspberry Pi is a super-cool, super-small, super-cheap microcomputer. In fact, it's a super-cool, super-small, super-cheap microcomputer board, and it doesn't do much on its own. Before you can do super-clever things with it, you have to add some extras to build a Pi system.
The Raspberry Pi, shown in Figure 1-1, is a tiny computer developed in the UK by the Raspberry Pi Foundation (www.raspberrypi.org). It's much smaller than a Mac or PC - it's almost exactly the same size as a credit card! And it's also much cheaper. (Prices vary, but a Pi costs around $30 in the United States and between £20 to £30 in the UK.)
www.raspberrypi.org
Figure 1-1
The Pi only comes in Raspberry. There is no Apple Pi, Blueberry Pi, or Pumpkin Pi. A lot of people like Raspberry, so that's fine with Pi fans.
Here are a few of the things you can do with a Pi:
Although the Pi is a fully working computer, it's not a Mac, a PC, a tablet, or a games console. It's not as powerful as more expensive computers. Here are some things you can't do with a Pi:
Does that seem disappointing? It shouldn't.
To make up for it, you can do a lot of things with a Pi you can't do with a bigger computer. For example, you can
You can see now why the Pi is special. Unlike a PC or a Mac, it's so small and cheap you can buy a separate Pi for every project. You can leave it running all the time. And it comes with a good set of simple tools for writing software - all free.
The Pi follows an old British tradition. Back in the 1980s, the UK led the world in computers and computer companies with fancy names, like the Spectrum, the Dragon, the Tangerine, and the Acorn. These computers were much less powerful than the Pi, but many kids learned how to program on them. Some of those kids became professional software developers, and one of them went on to develop the Pi.
The Raspberry Pi Foundation wants to help the kids of the 2010s follow the same route and to have fun along the way.
Pi boards come in different types (see Table 1-1). You need to know about the differences so that you don't buy the wrong one.
Table 1-1 Comparing Raspberry Pi Models
Model
What It's Good For
A
Out of date now. Don't buy one!
B
Out of date.
A+
Smaller, cheaper, slower than a Pi 2. Only useful for special projects.
B+
Out of date. Get a Pi 2!
Pi 2 Model B
You want this one.
The older models are called the A and B boards. The newer models are called the A+ and B+ boards. As of early 2015, there's an even newer, faster, shinier, and better board called the Pi 2.
Figure 1-2 shows a Model B+ and a Model B.
Figure 1-2
The boards are the same size, and they use the same software. But they have different numbers of connectors and other bits and pieces.
I'll make it easy to choose: You want a Pi 2. The older models are out of date now. You can still buy them, but the Pi 2 is much better for almost everything.
What's the deal with the A+? It's a cut-down budget Pi board with some important bits missing. It's definitely not the Pi you want when you're starting out.
It may, sometimes, kind of, perhaps be the right board for small finished projects. But don't get one until you've read the rest of this book!
There is no Pi 2 Model A/A+ - at least, not yet. It's possible the Pi people will start selling one by the end of 2015. Or maybe 2016. Or never. You'll have to wait and see. If they do, it could be a cheaper option for finished projects. No one knows yet. And if it appears, your first Pi should still be a Pi 2 B, not an A.
When you buy a Raspberry Pi, you get a small circuit board. And that's it. On its own, the board does nothing. You can't do anything with it, except look at it, and maybe play catch, which is fun but not what it's made for.
To turn a Pi board into a working computer, you have to add some extras. Collecting all the extras and connecting them to the Pi is your first project. And it's a big one!
Here's a list of what you need:
Try to do it yourself and ask for help from a grown-up only if you get stuck. You'll learn a lot about getting started with computers. If you want to save time and maybe money, skip to the "Collect Parts the Lazy Way" section, later in this chapter.
Are you getting a Pi 2? You don't need a hub. Did you get an old Model A+ or B+ board? You don't need a hub either.
Otherwise, there's something you need to know: the original A/B models had a problem: If you plugged a keyboard and mouse into the USB connectors, the Pi often stopped working.
Figure 1-3 shows how you have to fix this issue by connecting everything to the Pi, including a keyboard, and mouse, through a USB hub.
Figure 1-3
The hub has to have its own separate power supply. The hub solves the problem, but leaves you with a big mess of wires and connectors and stuff.
The A+/B+/2 models work fine without a hub, as shown in Figure 1-4. This makes them easier to set up. They don't need so many wires and cables.
Figure 1-4
A hub is a box with plenty of USB connectors. You plug one end into a single socket on the Pi, and then you plug all your other USB extras into the hub. If the hub has its own power supply, it makes sure that everything gets the power it needs.
If you plug things that use a lot of electricity to whirr or flash, like robot motors and killer lasers, you need a hub even on a Model A/+ and B+. Small things like keyboards and mice don't need one.
You can use any mouse or keyboard with a USB plug. Models with a cable should just work. You can probably use wireless models, as long as they come with a USB receiver dongle. (Anything made by Logitech should work.) Bluetooth mice and keyboards probably won't work.
You don't need to spend a lot of money on these extras. Basic models are fine.
You won't be using your Pi for serious gaming, so you don't need a Predator Ultra Galaxy Killer Destructo-Mouse with 15 buttons and a sharp and pointy design you can cut your fingers on. But if you have one spare, you can use it if you like. (The extra buttons won't do anything.)
The Pi can work with a monitor or a TV.
The best way to connect the Pi to a monitor is to use the HDMI socket. Most new TVs and many monitors have an HDMI socket that takes an HDMI cable. Hook up the cable to the Pi at one end and the monitor or TV at other, and you're done.
Figure 1-5 shows where the HDMI connector is.
Figure 1-5
The monitor/TV doesn't have to be very new, or very good. The Pi can barely produce HD video. Almost any monitor less than ten years old should work fine.
A few monitors have a different socket called a DVI-D connector. If you can't find a...
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