Raspberry Pi

The Raspberry Pi (www.raspberrypi.org), Model B is a small and unexpectedly powerful computer a bit bigger than a credit card that has a GPU capable of delivering high-definition (1080p) video, a 700MHz processor and 512Mb RAM.  It costs approximately $35 and requires an SD card (I recently bought for less than $20 a 32Gb ultra speed (10) SD card on Amazon.com). I also bought from Amazon.com Edimax wireless nano USB adapters for less than $12 each.

Below is a picture of the Raspberry Pi showing connections for wired Ethernet, HDMI, 2 USB, and power plus an SD slot and some more specialized connectors.

Various Linux distributions have been customized for the Raspberry Pi.  I have used both Raspbian, a general purpose distribution and RaspBMC, which is configured as a media server. A multi-boot environment, useful for development, has recently been introduced (called “NOOBS”).

A 5 megapixel native resolution camera is available for the Raspberry Pi which can capture video in h264 format.  Remarkably, this is available for less than $30.  I have built a security system for my home and a nature camera that monitors some bird feeders (or I should say squirrel feeders!) for my wife. A version of the camera is that is infrared-sensitive is also available for less than $30.  (Both are available at www.adafruit.com).

You can use a Raspberry Pi as a controller for external hardware.  The Raspberry Pi has 8 dedicated GPIO pins, a UART, i2c bus, SPI bus with two chip selects, i2s audio, 3v3, 5v, and ground.  I have used a USB connection to an Arduino board and have used a Gertboard (a daughterboard for the Raspberry Pi). 

The Gertboard is especially versatile having A-D and D-A converters, GPIO ports, open collector outputs, microswitches, LED indicators and motor control plus an on-board Atmel ATmega328 MCU.  In theory, it would be perfect for prototyping but it has had some issues with manufacturing quality, complexity, and poor protection of its GPIO ports. 

Gert van Loo, the creator of the Gertboard has recently created the GertDuino, another add-on board for the Raspberry Pi.  I do not as yet have experience with this device, but at a glance it appears to be less versatile than the Gertboard, more akin to an Arduino Uno, but interfaced as a daughterboard instead of through a USB connection. However, the GertDuino has two nice bonuses on-board: a real time clock and an infrared interface.

The Raspberry Pi is an ideal platform for digital signage, demonstration kiosks, and lighting control.  Implementation technologies that Headspace Sprockets has explored include using different combinations of Python, Node.js, Omxplayer, HTML 5 and other technologies.