We first featured the Raspberry Pi early last year when they were launched. We loved them, but we didn't realise just how much the rest of the world loved them too. We don't think that back then anyone did.
The Raspberry Pi has struck a chord with hobbyists the world over, in a way no other device in recent years has. The initial production run of 10,000 sold out so quickly that only the lucky and dedicated fans got one, and now they're selling as fast as factories can make them.
Frankly, this isn't surprising given that for around £30 you can get a fully working Linux computer featuring an ARM processor and 512MB of RAM (on boards shipped after 15 October) that's the size of a credit card. The goal of the project is to revolutionise out-dated computing education in the UK, but it's too early to see if it will achieve this.
One thing is for sure, though: the world of amateur hardware hacking will never be the same again. These diminutive, but fully functional, systems are perfect for adding processing power to unusual places where space and electricity are at a premium.
They've been sent into space and are being prepared to cross oceans, but are also being used for home brewing beer and driving remote control cars. We're going to look at some cool projects for the Pi and introduce you to the techniques you'll need to turn yours into the device of your dreams.
Thanks to the versatility and depth of Linux tools, it's easy to tune your Pi to be anything from a desktop computer to a media centre or hardware controller.
As you probably expect, there's a wide range of distros available on the Pi, and new ones seem to pop up every week. Here, we're going to take a look at some of the most popular, as well as a couple of novel ones.
You install a distro in a slightly different way than on a normal computer. Since everything runs off an SD card, all you have to do is write the new operating system to this card.
The easiest way of doing this is with the command-line tool dd. This tool does a bit-for-bit copy of data between a device and a file (or for that matter, two files or two devices).
Distros are supplied as image files (a bit like ISO files for CDs) that can be written to the disc, after being unzipped if necessary, with:
sudo dd if=<image-file> of=<sd-card-device> bs=4k
The second line ensures that all the data is written to the card and not stuck in any buffers. So, for example, on our test computer, which has two hard drives (sda and sdb), the SD card comes up as dev/sdc. If you aren't sure which device your SD card is, run df –h at the terminal, and it will list all the devices. You should be able to see which one it is.
To back up your Raspberry Pi setup, you can create a new image file by reversing the if (input file) and of (output file) flags in the dd command. That is:
sudo dd if=<sd-card-device> of=<new-imagefile> bs=4k
This image can then be compressed, using gzip or bzip so it doesn't take up too much hard drive space.
This is the recommended distro by the Raspberry Pi Foundation. Unless you have a good reason to use a different one, it's probably your best bet. It's based on Debian Wheezy, and so you can easily install anything from the huge Debian repositories.