REVIEW: RASPBERRY PI

Ultra small, ultra cheap computer for the masses

If you’ve not heard of the Raspberry Pi, it’s essentially a mobile computer designed to help kids get into programming.

It’s produced by the Raspberry Pi foundation, and sold here in the UK by Premier Farnell and RS Components.

The idea is that schools (and even kids themselves) can buy a slice of Pi and learn the basics of computer programming on their own equipment.

For now, it ships on its own.  But come September it’ll be available as a kit with all necessary accessories and training manuals.

Overview.

Lets start with a pic:

Hopefully that goes some way to showing just how small the Raspberry Pi is.

In slightly more technical speak, it’s a double-sided PCB with a variety of inputs and outputs available (more on that later).

There are two versions of the board.  The Model B is available now and costs $35 (plus taxes and shipping).  We’ve also been promised a Model A, which has slightly lower specifications, but only costs $25.

Both versions will feature the same basic hardware, but the Model B includes two USB ports (instead of one on the A) as well as a network port.

Both boards can output video via HDMI (with audio) or S-video, and can output audio via a 3.5mm connector to an amplifier or pair of speakers.

Both boards are powered via a Micro-USB connection, though no power supply is included.

What is included?

Buy your Raspberry Pi board now and that’s all you’ll get; the board.

There’s no power supply, data storage, manuals, software or case included (though cases are available online).

If you want any of the above accessories, then you can buy them from either of the official suppliers at the time of placing your order.

You’ll definitely need to find yourself a compatible power supply and a decent sized SD card, but a case is optional.

If you’re concerned about the lack of manuals and training guides, then you might want to wait until September when the educational pack is available for an additional fee.

Specifications

MODEL AMODEL B
Target price:[5]25 US$35 US$[52]
SoC:[5]Broadcom BCM2835 (CPUGPUDSP, and SDRAM)[3]
CPU:700 MHz ARM1176JZF-S core (ARM11 family)[3]
GPU:Broadcom VideoCore IV,[53] OpenGL ES 2.0, 1080p30 h.264/MPEG-4 AVC high-profile decoder[3]
Memory (SDRAM):256 MB (shared with GPU)
USB 2.0 ports:[10]12 (via integrated USB hub)[50]
Video outputs:[5]Composite RCA (PAL & NTSC), HDMI (rev 1.3 & 1.4),[54] raw LCD Panels via DSI[55][56]14 HDMI resolutions from 640×350 to 1920×1200 plus various PAL and NTSC standards.[57]
Audio outputs:[5]3.5 mm jack, HDMI
Onboard storage:[10]SD / MMC / SDIO card slot
Onboard network:[5][10]None10/100 Ethernet (RJ45)[50]
Low-level peripherals:8 × GPIOUARTI²C bus, SPI bus with two chip selects, +3.3 V, +5 V, ground[53][58]
Power ratings:500 mA (2.5 W)[5]700 mA (3.5 W)
Power source:[5]volt via MicroUSB or GPIO header
Size:85.60 × 53.98 mm (3.370 × 2.125 in)[59]
Weight:45 g (1.6 oz)[60]
Planned operating systems:Debian GNU/LinuxFedoraArch Linux ARM,[2] RISC OS[24]

As you can see, both models share the same essential hardware, the only differences are the additional USB port and the network port on the Model B.

The extra hardware also means that the Model B requires slightly more power; 3.5W compared to 2.5W for the Model A.

The processor is the same architecture that was used in the iPhone 3G (but slightly faster).  The 256MB of RAM might seem a little low by modern standards, but additional RAM would have bumped the cost of the Pi up quite substantially.

The specifications being what they are, this board is never going to set the world ablaze.  It also can’t run Windows due to the processor being based on ARM technology rather than Intel’s X86 architecture.

That being said, the Raspberry Pi Foundation promise that the Pi is powerful enough to play back Blu-Ray quality video (1080p), which could make it ideal as a media center using external storage.

It’s worth mentioning again that the Pi has no on board storage, and you can’t plug in a traditional hard disk.  Instead, you can only boot off of an SD card (not included).

So what’s it for?

The Raspberry Pi is primarily designed for use in the education sector, to teach children how to program computers rather than just use them.  Programming manuals will be available from September, but loads of resources are already appearing online from the Linux community which give plenty of information on how to use the Pi to write and compile your own programs.

Second to that, it’s got plenty of applications for home use.

Media center

Certain to be the most popular is use as a media center.  Already there are two branches of development of the popular XBMC software, which provides a very fluid interface including DVD covers, TV and movie information and plenty of flashy fan art.

Neither distribution is officially supported by Team-XBMC right now, but they may take them on at some point in the future if enough people use it.  They’re also both still in Beta phase, which means that you can expect the odd crash or odd behavior.  That being said, we’ve been running one of the distributions for a few days with no real issues, other than a sluggish user interface and the occasional system crash.

But, as time moves on, we’d expect a more stable version of XBMC to be released for the Pi.  Or, another form of media playback suite altogether, who knows?

One thing we can say for sure:  Yes the Raspberry Pi can play back video at full-HD.

Home Automation

The Raspberry Pi has a number of input and output pins on the board itself.  These can be used as inputs and outputs for a home automation system which would allow you to do a lot of neat things.

Think about this:  You have a light sensor connected to one of the inputs, and a relay connected to your light switch on one of the outputs.  The light level goes down in the room, the sensor sends a signal to the Pi, and the Pi sends a signal to the relay to tell the light switch to turn on.

Of course, this is an over-simplification.  There would be a lot of work involved to develop a suitable program, not to mention the effort of actually wiring up your home.

Program Development

The primary purpose of the Pi is to educate school children in computer programming, but there’s no reason that grown ups can’t partake as well.  If you’ve always been interested in programming but not wanted to interfere with your main PC, then the Raspberry Pi could be a great second machine for you.

Even if you don’t shell out for the development pack, you’ll be able to pick up a fair bit of information from the Internet.

Home network storage

More and more people are investing in home network storage systems these days.  The problem is, they’re blooming expensive.  Even a basic two bay Network storage drive will set you back around £150, which is a lot more than the Pi.

The Model B has two USB ports, so there’s no problem with connecting two large hard disks up and sticking it all into an old computer case: instant network storage.  The 700MHz processor and 256MB of RAM will be more than powerful enough to serve the needs of most home and small office users.

What’s more, one of the downloadable images from the Raspberry Pi website is a full Linux OS, which would be perfect for setting up external hard disks as network shares.

Web Server

If you work in web design, or just fancy taking a crack at developing your own website, then the Pi could be a great way to host your own site.

Connect it up to your network and load on a web server application and you can share your website with anyone in the world (with a bit of configuring on your home router).

The low power requirements make the Raspberry Pi ideal for leaving turned on all the time.  Even the more power-hungry Model B only draws 3.5W of power, which is next to nothing compared to even the most energy-efficient PC or laptop.

We’ve not even touched the surface of what you could potentially do with the Raspberry Pi.  The possibilities are quite possibly endless, given the imagination and drive of the online coding community.

Conclusions

We’ve had our Pi for a few days, so we’ve had a bit of time to play around with it.

The first thing we did was load up the officially supported Linux distribution, Debian Squeeze.  It’s pretty slow, but it is a full graphical operating system with a web browser, productivity suite, a wealth of programming tools and basic media player software.

In reality, it shows the limitations of the Raspberry Pi’s hardware.  The processor isn’t powerful enough to render YouTube videos properly, and the limited amount of memory means that doing more than one thing at a time will bring the system to its knees.

We’d advise against using the Raspberry Pi as a replacement for a full PC.

That being said, once we stuck XBMC onto our Pi, it became a whole new creature.  The interface isn’t quite as fluid as on a full PC, but it’s still perfectly usable.  The on board video decoder chip also allowed us to playback full HD video files with no loss of quality.  The fact that a sub-£30 board is capable of decoding full HD video is nothing short of incredible.

We’ve not been able to try out the Raspberry Pi on every available distribution, but if half of them are as usable as XBMC then it should prove to be an idea tool for a number of different things.

The only downside that we can see is that there is literally nothing included with the board when you buy from either of the UK suppliers.  Once you add a power supply, SD card, HDMI lead, keyboard and mouse you’re talking nearer to £50 than £30.  We’re not saying don’t buy one, just take that in to account when deciding whether or not to buy.

It’s hard to think of a reason not to buy the Raspberry Pi.  Even if you just want to mess around with UNIX commands or pick up the basics of programming, it would be hard to find a product with as many features for such a small price.

Our recommendation: Buy one!

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