The Raspberry Pi and Raspbian
In this article by William Harrington, author of the book Leaning Raspbian, we will learn about the Raspberry Pi, the Raspberry Pi Foundation and Raspbian, the official Linux-based operating system of Raspberry Pi.
In this article, we will cover:
(For more resources related to this topic, see here.)
- The Raspberry Pi
- History of the Raspberry Pi
- The Raspberry Pi hardware
- The Raspbian operating system
- Raspbian components
The Raspberry Pi
Despite first impressions, the Raspberry Pi is not a tasty snack. The Raspberry Pi is a small, powerful, and inexpensive single board computer developed over several years by the Raspberry Pi Foundation.
If you are a looking for a low cost, small, easy-to-use computer for your next project, or are interested in learning how computers work, then the Raspberry Pi is for you.
The Raspberry Pi was designed as an educational device and was inspired by the success of the BBC Micro for teaching computer programming to a generation. The Raspberry Pi Foundation set out to do the same in today’s world, where you don’t need to know how to write software to use a computer. At the time of printing, the Raspberry Pi Foundation had shipped over 2.5 million units, and it is safe to say that they have exceeded their expectations!
The Raspberry Pi Foundation is a not-for-profit charity and was founded in 2006 by Eben Upton, Rob Mullins, Jack Lang, and Alan Mycroft. The aim of this charity is to promote the study of computer science to a generation that didn’t grow up with the BBC Micro or the Commodore 64.
They became concerned about the lack of devices that a hobbyist could use to learn and experiment with. The home computer was often ruled out, as it was so expensive, leaving the hobbyist and children with nothing to develop their skills with.
History of the Raspberry Pi
Any new product goes through many iterations before mass production. In the case of the Raspberry Pi, it all began in 2006 when several concept versions of the Raspberry Pi based on the Atmel 8-bit ATMega664 microcontroller were developed. Another concept based on a USB memory stick with an ARM processor (similar to what is used in the current Raspberry Pi) was created after that. It took six years of hardware development to create the Raspberry Pi that we know and love today!
The official logo of the Raspberry Pi is shown in the following screenshot:
It wasn’t until August 2011 when 50 boards of the Alpha version of the Raspberry Pi were built. These boards were slightly larger than the current version to allow the Raspberry Pi Foundation, to debug the device and confirm that it would all work as expected. Twenty-five beta versions of the Raspberry Pi were assembled in December 2011 and auctioned to raise money for the Raspberry Pi Foundation. Only a single small error with these was found and corrected for the first production run.
The first production run consisted of 10,000 boards of Raspberry Pi manufactured overseas in China and Taiwan. Unfortunately, there was a problem with the Ethernet jack on the Raspberry Pi being incorrectly substituted with an incompatible part. This led to some minor shipping delays, but all the Raspberry Pi boards were delivered within weeks of their due date. As a bonus, the foundation was able to upgrade the Model A Raspberry Pi to 256 MB of RAM instead of the 128 MB that was planned. This upgrade in memory size allowed the Raspberry Pi to perform even more amazing tasks, such as real-time image processing.
The Raspberry Pi is now manufactured in the United Kingdom, leading to the creation of many new jobs. The release of the Raspberry Pi was met with great fanfare, and the two original retailers of the Raspberry Pi – Premier Farnell and RS components-sold out of the first batch within minutes.
The Raspberry Pi hardware
At the heart of Raspberry Pi is the powerful Broadcom BCM2835 “system on a chip”. The BCM2835 is similar to the chip at the heart of almost every smartphone and set top box in the world that uses ARM architecture. The BCM2835 CPU on the Raspberry Pi runs at 700 MHz and its performance is roughly equivalent to a 300 MHz Pentium II computer that was available back in 1999.
To put this in perspective, the guidance computer used in the Apollo missions was less powerful than a pocket calculator!
The Raspberry Pi comes with either 256 MB or 512 MB of RAM, depending on which model you buy. Hopefully, this will increase in future versions!
Graphics in the Raspberry Pi are provided by a Videocore 4 GPU. The graphic performance of the graphics processing unit (GPU) is roughly equivalent to the Xbox, launched in 2011, which cost many hundreds of dollars. These might seem like very low specifications, but they are enough to play Quake 3 at 1080p and full HD movies.
There are two ways to connect a display to the Raspberry Pi. The first is using a composite video cable and the second is using HDMI. The composite output is useful as you are able to use any old TV as a monitor. The HDMI output is recommended however, as it provides superior video quality. A VGA connection is not provided on the Raspberry Pi as it would be cost prohibitive. However, it is possible to use an HDMI to VGA/DVI converter for users who have VGA or DVI monitors.
The Raspberry Pi also supports an LCD touchscreen. An official version has not been released yet, although many unofficial ones are available. The Raspberry Pi Foundation says that they expect to release one this year.
The Raspberry Pi has several different variants: the Model A and the Model B. The Model A is a low-cost version and unfortunately omits the USB hub chip. This chip also functions as a USB to an Ethernet converter. The Raspberry Pi Foundation has also just released the Raspberry Pi Model B+ that has extra USB ports and resolves many of the power issues surrounding the Model B and Model B USB ports.
|Parameters||Model A||Model B||Model B+|
|RAM||256 MB||512 MB||512 MB|
|Available since||February 2012||February 2012||July 2014|
Did you know that the Raspberry Pi is so popular that if you search for raspberry pie in Google, they will actually show you results for the Raspberry Pi!
The success of the Raspberry Pi has encouraged many other groups to design accessories for the Raspberry Pi, and users to use them. These accessories range from a camera to a controller for an automatic CNC machine. Some of these accessories include:
|Raspberry Pi camera||http://www.raspberrypi.org/tag/camera-board/|
No matter how good the hardware of the Raspberry Pi is, without an operating system it is just a piece of silicon, fiberglass, and a few other materials. There are several different operating systems for the Raspberry Pi, including RISC OS, Pidora, Arch Linux, and Raspbian.
Currently, Raspbian is the most popular Linux-based operating system for the Raspberry Pi. Raspbian is an open source operating system based on Debian, which has been modified specifically for the Raspberry Pi (thus the name Raspbian). Raspbian includes customizations that are designed to make the Raspberry Pi easier to use and includes many different software packages out of the box.
Raspbian is designed to be easy to use and is the recommended operating system for beginners to start off with their Raspberry Pi.
The Debian operating system was created in August 1993 by Ian Murdock and is one of the original distributions of Linux.As Raspbian is based on the Debian operating system, it shares almost all the features of Debian, including its large repository of software packages. There are over 35,000 free software packages available for your Raspberry Pi, and they are available for use right now!
An excellent resource for more information on Debian, and therefore Raspbian, is the Debian administrator’s handbook. The handbook is available at http://debian-handbook.info.
The majority of the software that makes up Raspbian on the Raspberry Pi is open source. Open source software is a software whose source code is available for modification or enhancement by anyone.
The Linux kernel and most of the other software that makes up Raspbian is licensed under the GPLv2 License. This means that the software is made available to you at no cost, and that the source code that makes up the software is available for you to do what you want to. The GPLV2 license also removes any claim or warranty. The following extract from the GPLV2 license preamble gives you a good idea of the spirit of free software:
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