Raspberry Pi

The Raspberry Pi is a series of small single-board computers developed in the United Kingdom by the Raspberry Pi Foundation to promote teaching of basic computer science in schools and in developing countries. The original model became far more popular than anticipated, selling outside its target market for uses such as robotics. It is now widely used even in research projects, such as for weather monitoring because of its low cost and portability. It does not include peripherals or cases. However, some accessories have been included in several official and unofficial bundles.
After the release of the second board type, the Raspberry Pi Foundation set up a new entity, named Raspberry Pi Trading, and installed Eben Upton as CEO, with the responsibility of developing technology. The Foundation was rededicated as an educational charity for promoting the teaching of basic computer science in schools and developing countries.
The Raspberry Pi is one of the best-selling British computers. As of December 2019, more than thirty million boards have been sold. Most Pis are made in a Sony factory in Pencoed, Wales, while others are made in China and Japan.


Several generations of Raspberry Pis have been released. All models feature a Broadcom system on a chip with an integrated ARM-compatible central processing unit and on-chip graphics processing unit.
Processor speed ranges from 700 MHz to 1.4 GHz for the Pi 3 Model B+ or 1.5 GHz for the Pi 4; on-board memory ranges from 256 MiB to 1 GiB random-access memory, with up to 8 GiB available on the Pi 4. Secure Digital cards in MicroSDHC form factor are used to store the operating system and program memory. The boards have one to five USB ports. For video output, HDMI and composite video are supported, with a standard 3.5 mm tip-ring-sleeve jack for audio output. Lower-level output is provided by a number of GPIO pins, which support common protocols like I²C. The B-models have an 8P8C Ethernet port and the Pi 3, Pi 4 and Pi Zero W have on-board Wi-Fi 802.11n and Bluetooth. Prices range from US$5 to $55.
The first generation was released in February 2012, followed by the simpler and cheaper Model A. In 2014, the Foundation released a board with an improved design, Raspberry Pi Model B+. These boards are approximately credit-card sized and represent the standard mainline form-factor. Improved A+ and B+ models were released a year later. A [|"Compute Module"] was released in April 2014 for embedded applications.
The Raspberry Pi 2, which featured a 900 MHz quad-core ARM Cortex-A7 processor and 1 GiB RAM, was released in February 2015.
A Raspberry Pi Zero with smaller size and reduced input/output and general-purpose input/output capabilities was released in November 2015 for US$5. On 28 February 2017, the Raspberry Pi Zero W was launched, a version of the Zero with Wi-Fi and Bluetooth capabilities, for US$10. On 12 January 2018, the Raspberry Pi Zero WH was launched, a version of the Zero W with pre-soldered GPIO headers.
Raspberry Pi 3 Model B was released in February 2016 with a 1.2 GHz 64-bit quad core processor, on-board 802.11n Wi-Fi, Bluetooth and USB boot capabilities. On Pi Day 2018, the Raspberry Pi 3 Model B+ was launched with a faster 1.4 GHz processor and a three-times faster gigabit Ethernet or 2.4 / 5 GHz dual-band 802.11ac Wi-Fi. Other features are Power over Ethernet , USB boot and network boot.
Raspberry Pi 4 Model B was released in June 2019 with a 1.5 GHz 64-bit quad core ARM Cortex-A72 processor, on-board 802.11ac Wi-Fi, Bluetooth 5, full gigabit Ethernet, two USB 2.0 ports, two USB 3.0 ports, and dual-monitor support via a pair of micro HDMI ports for up to 4K resolution. The Pi 4 is also powered via a USB-C port, enabling additional power to be provided to downstream peripherals, when used with an appropriate PSU. The initial Raspberry Pi 4 board has a design flaw where third-party e-marked USB cables, such as those used on Apple MacBooks, incorrectly identify it and refuse to provide power. Tom's Hardware tested 14 different cables and found that 11 of them turned on and powered the Pi without issue. The design flaw was fixed in revision 1.2 of the board, released in late 2019.
FamilyModelForm FactorEthernetWirelessGPIOReleasedDiscontinued
Raspberry PiBStandardYesNo26-pin2012Yes
Raspberry PiAStandardNoNo26-pin2013Yes
Raspberry PiB+StandardYesNo40-pin2014
Raspberry PiA+CompactNoNo40-pin2014
Raspberry Pi 2BStandardYesNo40-pin2015
Raspberry Pi ZeroZeroZeroNoNo40-pin2015
Raspberry Pi ZeroW/WHZeroNoYes40-pin2017
Raspberry Pi 3BStandardYesYes40-pin2016
Raspberry Pi 3A+CompactNoYes40-pin2018
Raspberry Pi 3B+StandardYesYes40-pin2018
Raspberry Pi 4B StandardYes Yes40-pin2019Yes
Raspberry Pi 4B StandardYes Yes40-pin2019
Raspberry Pi 4B StandardYes Yes40-pin2019
Raspberry Pi 4B StandardYes Yes40-pin2020


The Raspberry Pi hardware has evolved through several versions that feature variations in the type of the central processing unit, amount of memory capacity, networking support, and peripheral-device support.
This block diagram describes Model B and B+; Model A, A+, and the Pi Zero are similar, but lack the Ethernet and USB hub components. The Ethernet adapter is internally connected to an additional USB port. In Model A, A+, and the Pi Zero, the USB port is connected directly to the system on a chip. On the Pi 1 Model B+ and later models the USB/Ethernet chip contains a five-port USB hub, of which four ports are available, while the Pi 1 Model B only provides two. On the Pi Zero, the USB port is also connected directly to the SoC, but it uses a micro USB port. Unlike all other Pi models, the 40 pin GPIO connector is omitted on the Pi Zero with solderable through holes only in the pin locations. The Pi Zero WH remedies this.


All SoCs used in Raspberry Pis are custom-developed under collaboration of Broadcom and Raspberry Pi Foundation.
The Broadcom BCM2835 SoC used in the first generation Raspberry Pi includes a 700 MHz ARM1176JZF-S processor, VideoCore IV graphics processing unit, and RAM. It has a level 1 cache of 16 KiB and a level 2 cache of 128 KiB. The level 2 cache is used primarily by the GPU. The SoC is stacked underneath the RAM chip, so only its edge is visible. The ARM1176JZ-S is the same CPU used in the original iPhone, although at a higher clock rate, and mated with a much faster GPU.
The earlier V1.1 model of the Raspberry Pi 2 used a Broadcom BCM2836 SoC with a 900 MHz 32-bit, quad-core ARM Cortex-A7 processor, with 256 KiB shared L2 cache. The Raspberry Pi 2 V1.2 was upgraded to a Broadcom BCM2837 SoC with a 1.2 GHz 64-bit quad-core ARM Cortex-A53 processor, the same SoC which is used on the Raspberry Pi 3, but underclocked to the same 900 MHz CPU clock speed as the V1.1. The BCM2836 SoC is no longer in production as of late 2016.
The Raspberry Pi 3 Model B uses a Broadcom BCM2837 SoC with a 1.2 GHz 64-bit quad-core ARM Cortex-A53 processor, with 512 KiB shared L2 cache. The Model A+ and B+ are 1.4 GHz
The Raspberry Pi 4 uses a Broadcom BCM2711 SoC with a 1.5 GHz 64-bit quad-core ARM Cortex-A72 processor, with 1 MiB shared L2 cache. Unlike previous models, which all used a custom interrupt controller poorly suited for virtualisation, the interrupt controller on this SoC is compatible with the ARM Generic Interrupt Controller architecture 2.0, providing hardware support for interrupt distribution when using ARM virtualisation capabilities.
The Raspberry Pi Zero and Zero W use the same Broadcom BCM2835 SoC as the first generation Raspberry Pi, although now running at 1 GHz CPU clock speed.


While operating at 700 MHz by default, the first generation Raspberry Pi provided a real-world performance roughly equivalent to 0.041 GFLOPS. On the CPU level the performance is similar to a 300 MHz Pentium II of 1997–99. The GPU provides 1 Gpixel/s or 1.5 Gtexel/s of graphics processing or 24 GFLOPS of general purpose computing performance. The graphical capabilities of the Raspberry Pi are roughly equivalent to the performance of the Xbox of 2001.
Raspberry Pi 2 V1.1 included a quad-core Cortex-A7 CPU running at 900 MHz and 1 GiB RAM. It was described as 4–6 times more powerful than its predecessor. The GPU was identical to the original. In parallelised benchmarks, the Raspberry Pi 2 V1.1 could be up to 14 times faster than a Raspberry Pi 1 Model B+.
The Raspberry Pi 3, with a quad-core ARM Cortex-A53 processor, is described as having ten times the performance of a Raspberry Pi 1. Benchmarks showed the Raspberry Pi 3 to be approximately 80% faster than the Raspberry Pi 2 in parallelised tasks.


Most Raspberry Pi systems-on-chip could be overclocked to 800 MHz, and some to 1000 MHz. There are reports the Raspberry Pi 2 can be similarly overclocked, in extreme cases, even to 1500 MHz. In the [|Raspbian] Linux distro the overclocking options on boot can be done by a software command running "sudo raspi-config" without voiding the warranty. In those cases the Pi automatically shuts the overclocking down if the chip temperature reaches, but it is possible to override automatic over-voltage and overclocking settings ; an appropriately sized heat sink is needed to protect the chip from serious overheating.
Newer versions of the firmware contain the option to choose between five overclock presets that when used, attempt to maximise the performance of the SoC without impairing the lifetime of the board. This is done by monitoring the core temperature of the chip and the CPU load, and dynamically adjusting clock speeds and the core voltage. When the demand is low on the CPU or it is running too hot the performance is throttled, but if the CPU has much to do and the chip's temperature is acceptable, performance is temporarily increased with clock speeds of up to 1 GHz, depending on the board version and on which of the turbo settings is used.
The overclocking modes are:
In the highest mode the SDRAM clock speed was originally 500 MHz, but this was later changed to 600 MHz because of occasional SD card corruption. Simultaneously, in high mode the core clock speed was lowered from 450 to 250 MHz, and in medium mode from 333 to 250 MHz.
The CPU of the first and second generation Raspberry Pi board did not require cooling with a heat sink or fan, even when overclocked, but the Raspberry Pi 3 may generate more heat when overclocked.


The early designs of the Raspberry Pi Model A and B boards included only 256 MiB of random access memory. Of this, the early beta Model B boards allocated 128 MiB to the GPU by default, leaving only 128 MiB for the CPU. On the early 256 MiB releases of models A and B, three different splits were possible. The default split was 192 MiB for the CPU, which should be sufficient for standalone 1080p video decoding, or for simple 3D processing. 224 MiB was for Linux processing only, with only a 1080p framebuffer, and was likely to fail for any video or 3D. 128 MiB was for heavy 3D processing, possibly also with video decoding. In comparison, the Nokia 701 uses 128 MiB for the Broadcom VideoCore IV.
The later Model B with 512 MiB RAM, was released on 15 October 2012 and was initially released with new standard memory split files with 256 MiB, 384 MiB, and 496 MiB CPU RAM, and with 256 MiB, 128 MiB, and 16 MiB video RAM, respectively. But about one week later, the foundation released a new version of start.elf that could read a new entry in config.txt and could dynamically assign an amount of RAM to the GPU, obsoleting the older method of splitting memory, and a single start.elf worked the same for 256 MiB and 512 MiB Raspberry Pis.
The Raspberry Pi 2 has 1 GiB of RAM. The Raspberry Pi 3 has 1 GiB of RAM in the B and B+ models, and 512 MiB of RAM in the A+ model. The Raspberry Pi Zero and Zero W have 512 MiB of RAM.
The Raspberry Pi 4 is available with 2, 4 or 8 GiB of RAM. A 1GiB model was originally available at launch in June 2019 but was discontinued in March 2020, and the 8 GiB model was introduced in May 2020.


The Model A, A+ and Pi Zero have no Ethernet circuitry and are commonly connected to a network using an external user-supplied USB Ethernet or Wi-Fi adapter. On the the Ethernet port is provided by a built-in USB Ethernet adapter using the SMSC LAN9514 chip. The Raspberry Pi 3 and Pi Zero W are equipped with 2.4 GHz WiFi 802.11n and Bluetooth 4.1 based on the Broadcom BCM43438 FullMAC chip with no official support for monitor mode but implemented through unofficial firmware patching and the Pi 3 also has a 10/100 Mbit/s Ethernet port. The Raspberry Pi 3B+ features dual-band IEEE 802.11b/g/n/ac WiFi, Bluetooth 4.2, and Gigabit Ethernet. The Raspberry Pi 4 has full gigabit Ethernet

Special-purpose features

The Pi Zero, Pi1A and Pi3A+ can be used as a USB device or "USB gadget", plugged into another computer via a USB port on another machine. It can be configured in multiple ways, for example to show up as a serial device or an ethernet device. Although originally requiring software patches, this was added into the mainline Raspbian distribution in May 2016.
The Pi 3 can boot from USB, such as from a flash drive. Because of firmware limitations in other models, the Pi 2B v1.2, 3A+, 3B, and 3B+ are the only boards that can do this.


Although often pre-configured to operate as a headless computer, the Raspberry Pi may also optionally be operated with any generic USB computer keyboard and mouse. It may also be used with USB storage, USB to MIDI converters, and virtually any other device/component with USB capabilities, depending on the installed device drivers in the underlying operating system.
Other peripherals can be attached through the various pins and connectors on the surface of the Raspberry Pi.


The video controller can generate standard modern TV resolutions, such as HD and Full HD, and higher or lower monitor resolutions as well as older NTSC or PAL standard CRT TV resolutions. As shipped it can support the following resolutions: 640×350 EGA; 640×480 VGA; 800×600 SVGA; 1024×768 XGA; 1280×720 720p HDTV; 1280×768 WXGA variant; 1280×800 WXGA variant; 1280×1024 SXGA; 1366×768 WXGA variant; 1400×1050 SXGA+; 1600×1200 UXGA; 1680×1050 WXGA+; 1920×1080 1080p HDTV; 1920×1200 WUXGA.
Higher resolutions, up to 2048×1152, may work or even 3840×2160 at 15 Hz. Allowing the highest resolutions does not imply that the GPU can decode video formats at these resolutions; in fact, the Pis are known to not work reliably for H.265, commonly used for very high resolutions.
Although the Raspberry Pi 3 does not have H.265 decoding hardware, the CPU is more powerful than its predecessors, potentially fast enough to allow the decoding of H.265-encoded videos in software. The GPU in the Raspberry Pi 3 runs at higher clock frequencies of 300 MHz or 400 MHz, compared to previous versions which ran at 250 MHz.
The Raspberry Pis can also generate 576i and 480i composite video signals, as used on old-style TV screens and less-expensive monitors through standard connectorseither RCA or 3.5 mm phono connector depending on model. The television signal standards supported are PAL-BGHID, PAL-M, PAL-N, NTSC and NTSC-J.

Optional real-time clock

As of the introduction of the Pi 4 B, no Raspberry Pi model has a built-in real-time clock. When booting, the time defaults to being set over the network using the Network Time Protocol. The source of time information can be another computer on the local network that does have a real-time clock, or to a NTP server on the internet which in turn gets time information from an atomic clock at the National Institute of Standards and Technology . If no network connection is available, the time may be set manually or configured to assume that no time passed during the shutdown. In the latter case, the time is monotonic but may be considerably earlier than the actual time. For systems that require a built-in real-time clock, an number of small, low-cost add-on boards with real-time clocks are available.


Pi Zero

Model A

Model B

General purpose input-output (GPIO) connector

Raspberry Pi 1 Models A+ and B+, Pi 2 Model B, Pi 3 Models A+, B and B+, Pi 4, and Pi Zero, Zero W, and Zero WH GPIO J8 have a 40-pin pinout. Raspberry Pi 1 Models A and B have only the first 26 pins.
In the Pi Zero and Zero W the 40 GPIO pins are unpopulated, having the through-holes exposed for soldering instead. The Zero WH has the header pins preinstalled.
Model B rev. 2 also has a pad of 8 pins offering access to an additional 4 GPIO connections. These GPIO pins were freed when the four board version identification links present in revision 1.0 were removed.
GPIO#2nd func.Pin#Pin#2nd func.GPIO#
+5 V12+3.3 V

Models A and B provide GPIO access to the ACT status LED using GPIO 16. Models A+ and B+ provide GPIO access to the ACT status LED using GPIO 47, and the power status LED using GPIO 35.



Operating systems

The Raspberry Pi Foundation provides Raspberry Pi OS, a Debian-based Linux distribution for download, as well as third-party Ubuntu, Windows 10 IoT Core, RISC OS, and LibreELEC. It promotes Python and Scratch as the main programming languages, with support for many other languages. The default firmware is closed source, while unofficial open source is available. Many other operating systems can also run on the Raspberry Pi. Third-party operating systems available via the official website include Ubuntu MATE, Windows 10 IoT Core, RISC OS and specialised distributions for the Kodi media centre and classroom management. The formally verified microkernel is also supported.
;Other operating systems
;Other operating systems
Raspberry Pi can use a VideoCore IV GPU via a binary blob, which is loaded into the GPU at boot time from the SD-card, and additional software, that initially was closed source. This part of the driver code was later released. However, much of the actual driver work is done using the closed source GPU code. Application software makes calls to closed source run-time libraries, which in turn call an open source driver inside the Linux kernel, which then calls the closed source VideoCore IV GPU driver code. The API of the kernel driver is specific for these closed libraries. Video applications use OpenMAX, use OpenGL ES and use OpenVG, which both in turn use EGL. OpenMAX and EGL use the open source kernel driver in turn.

Vulkan driver

The Raspberry Pi Foundation first announced it was working on a Vulkan driver in February of 2020. A working Vulkan driver running Quake 3 at 100 frames per second on a 3B+ was revealed by a graphics engineer that had been working on it as a hobby project on June 20th.


The official firmware is a freely redistributable binary blob, that is proprietary software. A minimal proof-of-concept open source firmware is also available, mainly aimed at initialising and starting the ARM cores as well as performing minimal startup that is required on the ARM side. It is also capable of booting a very minimal Linux kernel, with patches to remove the dependency on the mailbox interface being responsive. It is known to work on Raspberry Pi 1, 2 and 3, as well as some variants of Raspberry Pi Zero.

Third-party application software

In February 2015, a switched-mode power supply chip, designated U16, of the Raspberry Pi 2 Model B version 1.1 was found to be vulnerable to flashes of light, particularly the light from xenon camera flashes and green and red laser pointers. However, other bright lights, particularly ones that are on continuously, were found to have no effect. The symptom was the Raspberry Pi 2 spontaneously rebooting or turning off when these lights were flashed at the chip. Initially, some users and commenters suspected that the electromagnetic pulse from the xenon flash tube was causing the problem by interfering with the computer's digital circuitry, but this was ruled out by tests where the light was either blocked by a card or aimed at the other side of the Raspberry Pi 2, both of which did not cause a problem. The problem was narrowed down to the U16 chip by covering first the system on a chip and then U16 with Blu-Tack. Light being the sole culprit, instead of EMP, was further confirmed by the laser pointer tests, where it was also found that less opaque covering was needed to shield against the laser pointers than to shield against the xenon flashes. The U16 chip seems to be bare silicon without a plastic cover, which would, if present, block the light. Unofficial workarounds include covering U16 with opaque material, putting the Raspberry Pi 2 in a case, and avoiding taking photos of the top side of the board with a xenon flash. This issue was not discovered before the release of the Raspberry Pi 2 because it is not standard or common practice to test susceptibility to optical interference, while commercial electronic devices are routinely subjected to tests of susceptibility to radio interference.

Reception and use

Technology writer Glyn Moody described the project in May 2011 as a "potential ", not by replacing machines but by supplementing them. In March 2012 Stephen Pritchard echoed the BBC Micro successor sentiment in ITPRO. Alex Hope, co-author of the Next Gen report, is hopeful that the computer will engage children with the excitement of programming. Co-author Ian Livingstone suggested that the BBC could be involved in building support for the device, possibly branding it as the BBC Nano. The Centre for Computing History strongly supports the Raspberry Pi project, feeling that it could "usher in a new era". Before release, the board was showcased by ARM's CEO Warren East at an event in Cambridge outlining Google's ideas to improve UK science and technology education.
Harry Fairhead, however, suggests that more emphasis should be put on improving the educational software available on existing hardware, using tools such as Google App Inventor to return programming to schools, rather than adding new hardware choices. Simon Rockman, writing in a ZDNet blog, was of the opinion that teens will have "better things to do", despite what happened in the 1980s.
In October 2012, the Raspberry Pi won T3's Innovation of the Year award, and futurist Mark Pesce cited a Raspberry Pi as the inspiration for his ambient device project MooresCloud. In October 2012, the British Computer Society reacted to the announcement of enhanced specifications by stating, "it's definitely something we'll want to sink our teeth into."
In June 2017, Raspberry Pi won the Royal Academy of Engineering MacRobert Award. The citation for the award to the Raspberry Pi said it was "for its inexpensive credit card-sized microcomputers, which are redefining how people engage with computing, inspiring students to learn coding and computer science and providing innovative control solutions for industry."
Clusters of hundreds of Raspberry Pis have been used for testing programs destined for supercomputers


The Raspberry Pi community was described by Jamie Ayre of FLOSS software company AdaCore as one of the most exciting parts of the project. Community blogger Russell Davis said that the community strength allows the Foundation to concentrate on documentation and teaching. The community developed a fanzine around the platform called The MagPi which in 2015, was handed over to the Raspberry Pi Foundation by its volunteers to be continued in-house. A series of community Raspberry Jam events have been held across the UK and around the world.


, enquiries about the board in the United Kingdom have been received from schools in both the state and private sectors, with around five times as much interest from the latter. It is hoped that businesses will sponsor purchases for less advantaged schools. The CEO of Premier Farnell said that the government of a country in the Middle East has expressed interest in providing a board to every schoolgirl, to enhance her employment prospects.
In 2014, the Raspberry Pi Foundation hired a number of its community members including ex-teachers and software developers to launch a set of free learning resources for its website. The Foundation also started a teacher training course called Picademy with the aim of helping teachers prepare for teaching the new computing curriculum using the Raspberry Pi in the classroom.
In 2018, NASA launched the JPL Open Source Rover Project, which is a scaled down of Curiosity rover and uses a Raspberry Pi as the control module, to encourage students and hobbyists to get involved in mechanical, software, electronics, and robotics engineering.

Home automation

There are a number of developers and applications that are using the Raspberry Pi for home automation. These programmers are making an effort to modify the Raspberry Pi into a cost-affordable solution in energy monitoring and power consumption. Because of the relatively low cost of the Raspberry Pi, this has become a popular and economical alternative to the more expensive commercial solutions.

Industrial automation

In June 2014, Polish industrial automation manufacturer TECHBASE released ModBerry, an industrial computer based on the Raspberry Pi Compute Module. The device has a number of interfaces, most notably RS-485/232 serial ports, digital and analogue inputs/outputs, CAN and economical 1-Wire buses, all of which are widely used in the automation industry. The design allows the use of the Compute Module in harsh industrial environments, leading to the conclusion that the Raspberry Pi is no longer limited to home and science projects, but can be widely used as an Industrial IoT solution and achieve goals of Industry 4.0.
In March 2018, SUSE announced commercial support for SUSE Linux Enterprise on the Raspberry Pi 3 Model B to support a number of undisclosed customers implementing industrial monitoring with the Raspberry Pi.

Commercial products

OTTO is a digital camera created by Next Thing Co. It incorporates a Raspberry Pi Compute Module. It was successfully crowd-funded in a May 2014 Kickstarter campaign.
Slice is a digital media player which also uses a Compute Module as its heart. It was crowd-funded in an August 2014 Kickstarter campaign. The software running on Slice is based on Kodi.

COVID-19 pandemic

In Q1 of 2020, during the coronavirus pandemic, Raspberry Pi computers saw a large increase in demand primarily due to the increase in working from home, but also because of the use of many Raspberry Pi Zeros in ventilators for COVID-19 patients in countries such as Colombia, which were used to combat strain on the healthcare system. In March 2020, Raspberry Pi sales reached 640,000 units, the second largest month of sales in the company's history.

Astro Pi

A project was launched in December 2014 at an event held by the UK Space Agency. The Astro Pis are augmented Raspberry Pis and included Sensor Hats and either a visible-light Raspberry Pi camera or an infrared raspberry Pi camera. The Astro Pi competition, called Principia, was officially opened in January and was opened to all primary and secondary school aged children who were residents of the United Kingdom. During his mission, British ESA astronaut Tim Peake deployed the computers on board the International Space Station. He loaded the winning code while in orbit, collected the data generated and then sent this to Earth where it was distributed to the winning teams. Covered themes during the competition included spacecraft sensors, satellite imaging, space measurements, data fusion and space radiation.
The organisations involved in the Astro Pi competition include the UK Space Agency, UKspace, Raspberry Pi, ESERO-UK and ESA.
In 2017, the European Space Agency ran another competition open to all students in the European Union called Proxima. The winning programs were ran on the ISS by Thomas Pesquet, a French astronaut.


In 2006, early concepts of the Raspberry Pi were based on the Atmel ATmega644 microcontroller. Its schematics and PCB layout are publicly available. Foundation trustee Eben Upton assembled a group of teachers, academics and computer enthusiasts to devise a computer to inspire children. The computer is inspired by Acorn's BBC Micro of 1981. The Model A, Model B and Model B+ names are references to the original models of the British educational BBC Micro computer, developed by Acorn Computers. The first ARM prototype version of the computer was mounted in a package the same size as a USB memory stick. It had a USB port on one end and an HDMI port on the other.
The Foundation's goal was to offer two versions, priced at US$25 and $35. They started accepting orders for the higher priced Model B on 29 February 2012, the lower cost Model A on 4 February 2013. and the even lower cost A+ on 10 November 2014. On 26 November 2015, the cheapest Raspberry Pi yet, the Raspberry Pi Zero, was launched at US$5 or £4. According to Upton, the name "Raspberry Pi" was chosen with "Raspberry" as an ode to a tradition of naming early computer companies after fruit, and "Pi" as a reference to the Python programming language.


According to the Raspberry Pi Foundation, more than 5 million Raspberry Pis were sold by February 2015, making it the best-selling British computer. By November 2016 they had sold 11 million units, and 12.5 million by March 2017, making it the third best-selling "general purpose computer". In July 2017, sales reached nearly 15 million, climbing to 19 million in March 2018. By December 2019, a total of 30 million devices had been sold.