How the Raspberry Pi Works

Why Choose the Raspberry Pi and Not Something Else?

The Raspberry Pi has a few competitors, although the foundation encourages people to clone its idea, so competitor might not be the right word. They include BeagleBoard and PandaBoard (which are both the names of the companies and their main devices). Both are nonprofit organizations but with slightly different goals than the Raspberry Pi Foundation. BeagleBoard is geared toward adult hardware tinkerers, and PandaBoard aims to make a mobile software-programming platform available at a reasonable price.

Like Raspberry Pi, they're both exposed boards with ARM processors and are HD video capable. But BeagleBoards and PandaBoards have more connectors and connection headers (bits of the board that can be used by soldering additional hardware) than the Raspberry Pi, and both devices are a bit larger. The following aren't exhaustive lists of components, but here are some features that differ from the Pi:

BeagleBoardandBeagleBoard-xM

Cortex A8-based processor made by Texas Instruments, running from 600 MHz to 720 MHz on the BeagleBoard (depending upon version) and 1 GHz on the xM.
128 MB RAM on the original BeagleBoard, but 256 MB and 512 MB RAM on the newer boards, respectively.
DVI-D monitor connector
S-video connector
Audio in and out (not just audio out)
One USB port on BeagleBoard and four USB ports on the xM
USB and DC power
No RCA or HDMI connector

PandaBoard and PandaBoard ES

Dual-core ARM Cortex A9 MPCore processor, also manufactured by Texas Instruments, running at 1GHz on the PandaBoard and 1.2 GHz on the ES
1 GB RAM
DVI-D monitor connector
LCD expansion header
Audio in and out
One USB on-the-go port and two standard USB ports
WiFi and Bluetooth connectivity
USB and DC power
No RCA connector

For its intended educational purposes, the Raspberry Pi has two major advantages over the others. First, it was conceived to be a complete working computer. You simply need to insert an SD card containing the OS, connect the peripherals and power, and it's ready to go. BeagleBoards and PandaBoards require hookup to a host computer for initial setup, and though they have similar processing capabilities, they take a little more know-how to get them fully functional.

Second, the other devices are much more expensive than the Raspberry Pi. For example, in April 2012, the pricing was $125 to $149 for the two main BeagleBoard models, and $174 to $182 each for the two PandaBoard models. These prices are a far cry from the $25 and $35 base prices of the Raspberry Pi. This doesn't mean that the other devices aren't for you. You just have to examine the specs and determine which machine best suits your needs. Given its functionality and price, the Raspberry Pi seems better poised to get computing power to the masses.

Hardware aside, software-based educational resources are available for anyone wishing to learn programming on current computers.

OLPC, Cotton Candy and Arduino

Some other devices merit mention here, namely OLPC laptops, the Cotton Candy stick computer and Arduino boards. One Laptop Per Child (OLPC) is a charitable group that also aims to get computers to kids, but it provides complete, durable, WiFi-enabled laptops to schoolchildren in developing nations. The XO-1.5 model runs at 1 GHz and has 1 GB of RAM and 4-32 GB of internal flash memory. Like the Raspberry Pi, it runs a specially developed Linux distribution.

The Cotton Candy is a thumb-drive sized device that, like the Pi, can turn your TV into a computer. It has an ARM Cortex-A9 processor running at 1.2 GHz, an ARM Mali-400MP high-def GPU, 1 GB of RAM, an SD card slot, WiFi, an HDMI port and USB connectors. It runs Android or Ubuntu Linux and virtualization clients for other OSs. Unlike the Pi, it's meant for accessing Web or media content rather than for programming education.

Arduino boards are microcontroller boards that have much smaller amounts of built-in memory and speed. They can, however, be used to build simple computers for controlling physical machines with parts such as motors or blinking lights, and can be used in conjunction with computers like the Pi. Anyone up for building a robot?