For other uses, see. For the dessert, see. The Raspberry Pi is a series of small developed in the by the to promote the teaching of basic in schools and in. The original model became far more popular than anticipated, selling outside its for uses such as. It does not include peripherals such as and and. However, some accessories have been included in several official and unofficial bundles. The first two models were developed by the. After the Pi Model B was released, the Foundation set up Raspberry Pi Trading, with as CEO, to develop the third model, the B+. Raspberry Pi Trading is responsible for developing the technology while the Foundation is an educational charity to promote the teaching of basic computer science in schools and in developing countries. According to the Raspberry Pi Foundation, more than 5 million Raspberry Pis were sold by February 2015, making it the best-selling. By November 2016 they had sold 11 million units, and 12. In July 2017, sales reached nearly 15 million. In March 2018, sales reached 19 million. Most Pis are made in a factory in , Wales; some are made in China or Japan. All models feature a SoC with an integrated -compatible CPU and GPU. Processor speed ranges from 700 MHz to 1. SD cards are used to store the operating system and program memory in either SDHC or MicroSDHC sizes. The boards have one to four ports. For video output, and are supported, with a standard 3. Lower-level output is provided by a number of pins, which support common protocols like. The B-models have an port and the Pi 3 and Pi Zero W have on-board and. The first generation Raspberry Pi 1 Model B 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 1 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 was released in April 2014 for. The Raspberry Pi 2, which added more , was released in February 2015. By 2017, it became the newest mainline Raspberry Pi. On 12 January 2018, the Raspberry Pi Zero WH was launched, the same version of the Zero W with pre-soldered GPIO headers. Raspberry Pi 3 Model B was released in February 2016 with a 64 bit processor, on-board , and USB boot capabilities. On 2018 model 3B+ appeared with a faster 1. Other options are: PoE , and an is no longer required. This block diagram describes Model B and B+; Model A, A+, and the Pi Zero are similar, but lack the and 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 SoC. On the Pi Zero, the USB port is also connected directly to the SoC, but it uses a OTG port. The Raspberry Pi 2B uses a 32-bit 900 MHz quad-core processor. The BCM2835 SoC used in the first generation Raspberry Pi includes a 700 76JZF-S processor, IV GPU , and RAM. It has a level 1 L1 of 16 and a level 2 L2 cache of 128 KB. The is used primarily by the GPU. The SoC is underneath the RAM chip, so only its edge is visible. The 1176JZ F -S is the same CPU used in the , although at a higher , and mated with a much faster GPU. The Raspberry Pi 2 V1. The BCM2836 SoC is no longer in production as of late 2016. The Raspberry Pi 3+ uses a Broadcom BCM2837B0 SoC with a 1. Performance While operating at 700 MHz by default, the first generation Raspberry Pi provided a real-world performance roughly equivalent to 0. On the level the performance is similar to a 300 MHz of
