Raspberry Pi

Raspberry Pi 3 Model B+. Source: Stanton 2018.
Raspberry Pi 3 Model B+. Source: Stanton 2018.

Raspberry Pi is a credit-card-sized single-board computer (SBC) designed in the UK. It was started with the idea of making computers affordable, accessible and fun to a new generation of programmers.

Since its first release in 2012, many variant models of the Pi have been released, from $5 to $35. By 2018, more than 20 million units of the Pi were sold.

Though it was conceived as an educational tool, Raspberry Pi has since been used for home automation, in industrial systems and even on the International Space Station. It's managed by the Raspberry Pi Foundation. The schematics are available but the board itself is not open hardware.

Discussion

  • What are some applications where Raspberry Pi is suitable?
    Some cool projects built with Pi. Source: Geeks Life 2018.

    It's ideal for beginners to learn about computers and programming. With Raspbian as the OS, Python and Scratch come by default. You can make music with Sonic Pi. Those interested in gaming, can play and even tweak Python-based games. You can setup a web server on the Pi. For scientific computing, start using Mathematica. The Pi can also handle streaming video, play audio/video or be used as a media centre.

    It's also a good platform to learn electronics, interface to sensors and build IoT projects. Many have used it for home automation projects. The small form factor and lower power requirements of Pi Zero enable battery-powered applications, possibly in remote areas. It can be used as an IoT gateway. With the increasing need for edge processing and analytics, the Pi has been used for such purposes.

    In general, while a microcontroller-based system (such as Arduino) is good at input/output, the Pi is more suitable for applications that require lot more data processing, involve media streaming, network with other devices, or manage multiple processes.

  • What interfaces does a Raspberry Pi expose?
    Pi pinout with board pin numbers in the middle and BCM numbering outside. Source: Hawkins 2014.
    Pi pinout with board pin numbers in the middle and BCM numbering outside. Source: Hawkins 2014.

    While some models remove some of these interfaces, the following are present on Pi 3 Model B+: 4 x USB 2.0, Gigabit Ethernet, HDMI, analogue audio/video 3.5mm jack, Camera Serial Interface (CSI), Display Serial Interface (DSI) and a 40-pin GPIO header. CSI can connect to a camera. DSI can connect to a touchscreen display. For wireless networking, there's 802.11ac, Bluetooth 4.2 and BLE.

    GPIO header supports common digital interfaces: I2C, SPI and UART. There are 17 pins for GPIO. There's also an I2S interface for audio output. All GPIO run on 3.3V and can give maximum 20mA. Due to these interfaces, the Pi's being used for IoT and robotics applications.

    One interface that the Pi lacks is Analog-to-Digital Converter (ADC). An external ADC must therefore be used to interface to analogue sensors. The Pi can also be expanded with HAT (Hardware Attached on Top) expansion boards.

  • What hardware variants of the Raspberry Pi have been released to date?
    Comparing the main variants of Raspberry Pi. Source: Raspberry Pi Docs 2019a.
    Comparing the main variants of Raspberry Pi. Source: Raspberry Pi Docs 2019a.

    There have been to date four generations of Raspberry Pi:

    • Gen1: Model B, Model A, Model B+, Model A+, Compute Module 1
    • Gen2: Pi 2 Model B, Pi Zero
    • Gen3: Pi 3 Model B, Pi 3 Model B+, Pi 3 Model A+, Pi Zero W, Pi Zero WH, Compute Module 3, Compute Module 3 Lite, Compute Module 3+
    • Gen4: Pi 4 Model B (1/2/4GB)

    Compute Module is for industrial applications.

    Higher generation boards have faster CPU and more memory. In terms of form factor, cost and capability, in decreasing order are B, A and Zero models. The "plus" variants are better than the plain ones of that generation. Wireless connectivity was introduced for the first time in third generation models. Hence, both Pi Zero W and WH belong here.

    SocialCompare gives a feature comparison of most variants. RasPi.TV gives a nice picture of all the boards.

  • How does one go about setting up a Raspberry Pi?
    Steps to connect Raspberry Pi to peripherals. Source: Joseph 2013, slide 14.
    Steps to connect Raspberry Pi to peripherals. Source: Joseph 2013, slide 14.

    Raspberry Pi is just the processing module. It offers a number of interfaces to connect peripherals. HDMI can be used to connect to a display monitor or TV screen. For older displays, there's an analogue video interface. USB ports can be use to connect mouse and keyboard.

    Ethernet port is for a wired LAN connection. Otherwise, on-board Wi-Fi of Pi 3 models can be used to connect to a wireless LAN. With older models, a USB-based Wi-Fi dongle can be used instead.

    There's a micro USB to power up the Pi. However, Pi won't do anything without an operating system and software to run it. These should be loaded into an SD card. Online instructions can guide you to prepare the SD card.

    To use the Pi from your desktop/laptop, read about headless mode and VNC.

  • How is the software support for Raspberry Pi?

    Raspberry Pi needs an operating system (OS). The official OS supported by the Foundation is Raspbian, which is based on Debian Linux distribution. Some Linux-based alternatives are Ubuntu MATE, Snappy Ubuntu Core and RaspBSD. There's also Windows 10 IoT Core, Android Things, PiNet, Weather Station and IchigoJam Pi.

    To use Pi as a media centre, we can use OpenELEC, LibreELEC or OSMC. RISC OS, developed in the 1980s for ARM processors, can be used. For those who prefer a command line interface, try Plan 9. To use Pi for gaming, try RetroPie, RecalBox, Lakka and PiPlay.

    Many of these can be installed using the NOOBS installer. You could also install them directly.

    Further software support depends on the OS used. For example, Raspbian comes pre-installed with Python, Scratch, Sonic Pi, Java, and more. Python libraries Rpi.GPIO and Wiring Pi are useful for IoT programming.

  • What resources can help a beginner learn Raspberry Pi?

    The official website is a good place to start. The FAQ page will clarify many basic questions.

    Get involved in the Pi community. Read the blog. Subscribe to the newsletter. Raspberry Jams are local meetups for sharing knowledge or collaborating on Pi projects. Use the Pi Forums to ask or give help. Get inspired by Pi projects that others have created.

    Search online for tutorials, books, and projects posted on community websites. Programming the Raspberry Pi by Simon Monk is recommended for beginners. For inspiration, visit Instructables and Hackaday.

    On Pi Day 2018, one blogger shared 314 useful resources for Raspberry Pi enthusiasts.

Milestones

1980

In the 1980s, BBC Micro in the UK and Commodore 64 in the US make computers accessible to home users. BASIC programming language could be used to program these computers.

2006
An early prototype built by Upton in 2006. Source: Heath 2018.
An early prototype built by Upton in 2006. Source: Heath 2018.

Eben Upton at the University of Cambridge notices how fewer students are applying for computer science courses. He blames it on the lack of affordable computers for educational purpose. Children have access to only games consoles (and tablets and smartphones in later years). They have become consumers of content rather than programmers. Upton builds a computer using off-the-shelf parts and a soldering iron. It runs on an Atmel microcontroller.

Oct
2008
Raspberry Pi logo. Source: Raspberry Pi 2019d.
Raspberry Pi logo. Source: Raspberry Pi 2019d.

At a meeting involving Eben Upton (now an SoC architect at Broadcom), Alan Mycroft and Pete Lomas, the vision for Raspberry Pi takes shape. It's not about giving kids a black box. It should be a bare board that helps them know its components, tinker into open source code and learn how computers work. The second prototype is built using Broadcom components. The name Raspberry Pi is also coined, "Pi" because it boots into Python. A logo is selected later in 2011 via an open competition.

May
2009

To develop the Raspberry Pi and promote basic computer science in schools, Raspberry Pi Foundation is formed as a charity. Despite having the Foundation, the next two years would prove difficult for realizing the hardware at its desired price point of $35.

May
2011

A thumb-drive prototype of the Raspberry Pi is released in the UK. A YouTube video of the same picks up 600,000 views in just two days. This is made possible by a low-cost ARM-based Broadcom SoC BCM2835 released in early 2011. The SoC was meant for applications such as electronic devices and digital signs, but now reimagined to power Raspberry Pi.

Aug
2011
Raspberry Pi Alpha board of 2011. Source: Heath 2018.
Raspberry Pi Alpha board of 2011. Source: Heath 2018.

The first 50 Raspberry Pi Alpha boards are released, built by Broadcom. The board has many features and interfaces that would become standard in later versions. However, it's $110 a piece plus slightly larger than the desired size of a credit card. Many design decisions are made to achieve the final $35 credit-card-sized Pi. The beta boards come out in December.

Feb
2012

The first Raspberry Pi Model B is released. Orders quickly reach 100,000. A simpler and cheaper variant of this called Model A is released in 2013. This has only 1 USB port and no Ethernet port.

2014

Raspberry Pi Model B+ and Model A+ are released. GPIO header increases from 26 to 40 pins. The new boards also use less power. Upton later comments that Model B+ is the one they intended to make back in 2012. The success of earlier models and high volumes driving down costs (2.5 million by February 2014), have helped achieve Model B+ at a retail price of $35.

Feb
2015

Raspberry Pi 2 Model B is released. Compared to Model B+, it doubles the RAM size from 512MB to 1GB. Speed increases from 700MHz to 900MHz. There are four USB ports rather than two, thus removing the need to get a USB hub. The SoC is based on quad-core ARM Cortex-A7.

Nov
2015

For applications that require fewer interfaces, there's already Model A and Model A+. By removing the pinout header, removing more interfaces, and reducing HDMI and USB to smaller form factors, Raspberry Pi Zero is released. It retails at only $5. It draws less than 1 Watt of power. In 2017, Zero W includes wireless connectivity. In 2018, Zero WH includes the GPIO pinout header.

Feb
2016

Raspberry Pi 3 Model B is released. It uses a 64-bit SoC. This becomes the first model to add wireless connectivity: Wi-Fi 802.11n and Bluetooth 4.1. This can also boot from a USB. In 2018, variants Pi 3 Model B+ and Pi 3 Model A+ are introduced with 802.11ac and Bluetooth 4.2.

2019

By end of February, 25 million units of Raspberry Pi are sold worldwide. In June, Raspberry Pi 4 Model B is released with support for 4K video.

References

  1. Benchoff, Brian. 2016. "Introducing the Raspberry Pi 3." Hackaday, February 28. Accessed 2019-03-22.
  2. Cawley, Christian. 2018. "11 Operating Systems You Can Run on Raspberry Pi." MakeUseOf, December 29. Accessed 2019-03-23.
  3. Day, Lewin. 2017. "8-Channel ADC For the Raspberry Pi." Hackaday, September 22. Accessed 2019-03-23.
  4. Dewald, Manuel. 2019. "7 resources for learning to use your Raspberry Pi." Opensource, March 11. Accessed 2019-03-22.
  5. Di Justo, Patrick. 2015. "Raspberry Pi or Arduino Uno? One Simple Rule to Choose the Right Board." Makezine, December 04. Accessed 2019-03-23.
  6. Dimitrakoudis, Dimitris. 2014. "The Raspberry Pi: Audio out through I2S." DimDim's Blog, December 08. Accessed 2019-03-22.
  7. Francis, Ben. 2018. "How to build your own private smart home with a Raspberry Pi and Mozilla’s Things Gateway." Mozilla Hacks, February 06. Accessed 2019-03-23.
  8. Geeks Life. 2018. "Top 10 Coolest Raspberry Pi Projects 2018." Geeks Life, via Hi 2Tech on YouTube, December 10. Accessed 2019-03-23.
  9. Hawkins, Matt. 2014. "Raspberry Pi B+ GPIO Header Details And Pinout." July 18. Accessed 2019-03-23.
  10. Heath, Nick. 2018. "Inside the Raspberry Pi: The story of the $35 computer that changed the world." TechRepublic, December 19. Accessed 2019-03-23.
  11. Joseph, Lentin. 2013. "Exploring Raspberry Pi." SlideShare, September 10. Accessed 2019-03-23.
  12. Lyons, Conor. 2015. "A History of The Raspberry Pi." Nova Digital Media, March 04. Accessed 2019-03-22.
  13. Mitchell, Robin. 2018. "Raspberry Pi For Beginners: The Basics." Maker Pro, August 23. Accessed 2019-03-22.
  14. Opensource. 2019. "What is a Raspberry Pi?" Opensource, Red Hat Inc. Accessed 2019-03-22.
  15. Peterson, Terren. 2017. "Raspberry Pi just turned 5. Here's a brief history of the world's tiniest hobbyist computer." freeCodeCamp, March 11. Accessed 2019-03-22.
  16. Piltch, Avram. 2019. "Raspberry Pi 4 Review: The New Gold Standard for Single-Board Computing." Tom's Hardware, June 24. Accessed 2019-06-25.
  17. Raspberry Pi. 2019a. "Homepage." Accessed 2019-03-23.
  18. Raspberry Pi. 2019b. "Downloads." Accessed 2019-03-23.
  19. Raspberry Pi. 2019c. "Raspbian." Accessed 2019-03-23.
  20. Raspberry Pi. 2019d. "Trademark rules and brand guidelines." Accessed 2019-03-23.
  21. Raspberry Pi. 2019e. "Raspberry Pi 3 Model B+." Accessed 2019-03-23.
  22. Raspberry Pi Docs. 2019a. "FAQs." Accessed 2019-06-25.
  23. Raspberry Pi Docs. 2019b. "Usage." Accessed 2019-03-23.
  24. Recipes@WatsonIoT. 2016. "Getting started with Edge Analytics in Watson IoT Platform." IBM Developer, July 01. Updated 2017-05-18. Accessed 2019-03-23.
  25. Stanton, Christopher. 2018. "Raspberry Pi 3 Model B Plus (B+) Technical Specifications." Community, Element14, March 09. Updated 2018-05-16. Accessed 2019-03-22.
  26. Torrone, Phillip. 2019. "25 million + Raspberry Pi computers sold." Blog, Adafruit, March 15. Accessed 2019-06-25.
  27. Wikipedia. 2019a. "Raspberry Pi." Wikipedia, March 14. Accessed 2019-03-22.
  28. Wikipedia. 2019b. "Raspberry Pi Foundation." Wikipedia, March 13. Accessed 2019-03-22.
  29. eLinux. 2018. "RPi HardwareHistory." eLinux, December 01. Accessed 2019-03-22.

Further Reading

  1. Heath, Nick. 2018. "Inside the Raspberry Pi: The story of the $35 computer that changed the world." TechRepublic, December 19. Accessed 2019-03-23.
  2. Mitchell, Robin. 2018. "Raspberry Pi For Beginners: The Basics." Maker Pro, August 23. Accessed 2019-03-22.
  3. Irani, Romin. 2016. "Start programming on Raspberry Pi with Python." OpenSourceForU, October 28. Accessed 2019-03-22.
  4. Dewald, Manuel. 2019. "7 resources for learning to use your Raspberry Pi." Opensource, March 11. Accessed 2019-03-22.
  5. Joseph, Lentin. 2013. "Exploring Raspberry Pi." SlideShare, September 10. Accessed 2019-03-23.

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Devopedia. 2021. "Raspberry Pi." Version 6, March 29. Accessed 2024-06-25. https://devopedia.org/raspberry-pi
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Last updated on
2021-03-29 02:37:21
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