Onderstaande tekst kwam ik tegen in CQ AMATEUR van maart 2013. Een leuk project om mee te experimenteren. Zowel met XBMC, Linux en hamsoftware voor digimodes.
BY MATT STULTZ,* KB3TAN
Raspberry Pi: A Tiny Computer for Big Projects
In 2011 at World Maker Faire, many makers got their first chance to see a little board that we had just begun hearing whispers about on the Internet. No bigger than a deck of cards, the Raspberry Pi is a fully-functional, Linux-powered computer- with the added bonus of including a set of general purpose I/O pins that can be accessed easily from the command line or with the help of a couple of simple scripting languages. The Raspberry Pi launched in March 2012, and soon makers across the globe started pumping out exciting projects using the device.
The Raspberry Pi Foundation
The Raspberry Pi was created by the Raspberry Pi Foundation with the goal of developing a small, low-cost computer that would be a useful platform for teaching kids how to get started with computer programming. The organization has designed two boards: the lower cost and less functional Model A and the currently available Model B board.
The Raspberry PI Foundation is a registered charity from Cambridgeshire, UK. It has set up distribution deals with multiple electronics suppliers around the world to help distribute the boards.
The Hardware
The Raspberry Pi Model B has a 700-MHz ARM processor with 512 Mb of RAM and a dedicated GPU unit capable of delivering full 1080P HD video. Two USB ports provide access for a keyboard and mouse, along with other USB accessories. HDMI video out allows you to have HD (high definition) video, but analog video is also supported with a composite RCA plug. Audio can also be sent over the HDMI, but an audio out jack is present as well. Onboard Ethernet gives your Pi and projects access to the Internet. Storage is solved with an SD card slot rather than using a full bulky hard drive. 17 GPIO pins round out the hardware. All this can be yours for the low low price of just $35. This price point is helping fuel the demand for the boards. [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”]
The Model A is similar but with less RAM, one USB port, and no onboard Ethernet. This helps drop the price down to $25 and reduces the amount of power that is required to run the device by half. At the time of the writing of this article, the Model A boards are not yet available for sale.
One criticism of the board is its lack of analog inputs. These would allow for easy access to many different types of sensors. This has largely been solved with the use of an extra external chip that can read analog sensors and then transmit the data back over a serial interface to the Raspberry PI.
The Software
The Raspberry Pi is designed to run a Linux operating system (although some users have shoehorned other operating systems on board). The standard OS is called Raspbian and is based on Debian Wheezy. Variations on this OS have been created to help users with specific desired operations for their device.
The Raspbmc distribution allows you to use your Pi as a media center with your HD television. Once everything is connected and configured, users can easily stream videos, music, and pictures across their network, right to their TV. Many commercial systems give you this functionality, but often at double the price and with fewer options and configurability.
Occidentalis was created as the hardware hacker distribution. Occidentalis gives greater access to the GPIO pins and enables common serial protocols like I2C on them. New updates have included such things as servo libraries and greater support for sensor modules. The Python scripting language comes pre-installed, allowing users to quickly get up and running writing their own apps to interact with the on-board hardware and any device connected to the GPIO pins.
Toppings for your Pi
With the popularity of the new system, it wasn’t long before many creators began releasing accessories to help users with their Pi needs. Maker extraordinaire Limor Fried (named 2012 Entrepreneur of the year by Entrepreneur magazine) of Adafruit Industries began selling small screens, keyboards, WiFi modules, and many other useful items along with their own custom creations. The Pi Cobbler is a breakout board that allows the user to easily be able to connect their Pi to a breadboard for prototyping new projects.
For those wanting a little more I/O power from their Raspberry Pis (or just don’t want to rewrite all of their Arduino code), the Wyolum open hardware group created the AlaMode Arduino compatible shield. The AlaMode shield is pin-compatible with a standard Arduino and is capable of accepting any of the numerous shields that have been created for the Arduino.
One downside to the design of the Pi that bothered me initially was how much the SD card stuck out of the side of the board. Of course I was not the only one who disliked this and Rick Winscot decided to turn to Kickstarter.com to help him fix the problem. Rick ran a successful campaign to build a micro SD card adapter that would allow you to plug a memory card into your Pi without having it stick out of the device <http://kck.st/OsmYH7>. I received my boards after backing the project and couldn’t be happier with them. They do exactly what they are supposed to and the build quality is excellent.
Bushels of Apps
In December of 2012 the Raspberry Pi foundation launched the “Pi Store,” an online venue for developers to give away or sell their applications for the Pi. Unlike some systems though, the Raspberry Pi does not require that you download your apps from the store. Apps may be downloaded from many sources around . . . → Read More: Raspberry Pi
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