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Raspberry Pi General Information
The Raspberry Pi is a series of small single-board computers developed in the UK by the Raspberry Pi Foundation to promote modern computer science in schools and developing electronic communities. Adding the 40-pin GPIO connector to the computer board allows developers not only to improve their programming skills but also to open new horizons in controlling processes and devices not available for desktop computers. According to the Raspberry Pi Foundation, the board's sales in July 2017 reached nearly 15 million units. The first generation of this new board type was developed and then released in February 2012 – Raspberry Pi Model B. Each Raspberry Pi board contains hardware modules which together make it a fully usable PC like a computer whose size fits the typical credit card (85/56 mm) size and small power consumption < 3.5 W. This makes this kind of single board computer one of the most popular in the developers' community. Today, there exist thousands of hardware implementation projects for users who want to learn the modern hardware and software controlling units and include them within their projects.
There are a dozen clones, even more powerful, sharing a common concept, size, and connectors (mostly GPIO, USB, Ethernet and CSI/DSI) with genuine RPIs, such as OrangePi, BananaPi and others. They differ in CPU (MCU), GPU, and RAM, and some are even more powerful than genuine Raspberries. Still, they are ARM-based and powered with Android or Linux.
Because the power consumption in the latest devices, such as Raspberry Pi 4 and 5, can exceed 20W, they are considered mains powered and, thus, in the IoT ecosystem, play the role of gateways, routers and, in general, fog-class devices rather than edge-class. Still, this classification is fuzzy as there are dozens of examples of how to use Raspberry Pi, e.g. sensors-network component.
Besides advanced fog-class devices, Raspberry recently started to hit the edge-class IoT development market (low-powered, end-node devices) with their RP2040 MCU.
Below is a short review of the hardware and specifications:
