What is a Raspberry PI?

Last updated on February 6th, 2022


Raspberry PI is a very cheap, damn small but complete Linux computer. It is produced by Raspberry PI Foundation, a UK-based charity aiming to help people to start programming and, generally, computing experience. Their mission is to put the power of computing and digital making into the hands of people all over the world.

Educators love PI because it makes simple and funny approaching to programming. It is also a loved part for DIYers because, beyond USB ports and ethernet port, it has connectors able to interface rs components and many other accessories with simple coding.

Technical Features

What is common to these boards is very low price (starting from 20$ for a complete computer) and all-in-one board (which includes processor, memory, USB and video ports, wireless connectivity (Wi-Fi and Bluetooth). This is the reason because it is referenced as single-board computer. Some models (named “Model B”) include also wired connection.

Another PIs common feature is that they use micro SD card instead of hard drive. USB ports are available in all models, but in PI Zero it requires an adapter. Model A have only 1 USB port, while all remaining PI models have 4 USB ports.

Raspberry Pi Zero WH PINS

First Raspberry PI board was marketed in 2012. Original PI (Raspberry Pi Model B) had a single core Broadcom SoC operating at 700MHz and 256MB of RAM. From here, several versions has been released with increasing CPU and RAM power, up to most recent Raspberry PI Foudation boards which are comparable with small Personal Computer.

GPU has been always sharing memory with RAM. From common “raspi-config” terminal command you can manage memory allocation according with your needs. Video output can be connected by hdmi port, which was doubled in new Raspberry PI models to enable extended screen.

All available PIs in commerce have Wi-Fi and bluetooth (BLE) connectivity. Older models had a GPIO composed of 26 pins (standard). From PI 2 onwards, it was replaced with a more rich 40-pin GPIO interfacing enabling Raspberry PI to communicate with external cheap sensors (like humidity sensor, ultrasonic distance sensor and so on).

For complete boards differences and specs, please refer Raspberry PI boards comparison guide, starting from cheapest Raspberry PI Zero W.

Raspberry PI vs Arduino

A common question regards comparison between Raspberry PI and Arduino. PI differs from Arduino, which is a microcontroller. In simple terms, Arduino is a small board which you must configure and tell it what to do and how. This means that you will not be able to have a desktop with Arduino untill you will not develop it. Raspberry PI is a complete linux computer, with a running operating system which allows more operations out-of-the-box, but needs a basic understanding of main linux commands.

Raspbery PI Operating System Setup Methods

Raspbian (based on Debian) has been for years the default PI OS. From 2020 Raspberry PI Foundation spinned its own default OS, which was named “Raspberry PI OS”. Raspbian remained alive for open source community maintaining this historical piece.

During last years many other linux distributions extended their support for PI. Some of these are Ubuntu, CentOS, Fedora and Risc OS (beside the obvious Debian).

Headless OS Meaning

In simplest configuration, Raspberry PI needs also a common Micro SD card and a power supply (can be same as many common smartphone chargers). You will only need a Wi-Fi (or wired) network to connect the board.

With those pieces, you can setup the so called “headless installation”. This means that you will install and manage your Raspberry PI operating system from a remote personal computer, without the need of other devices connected to your RPI (no monitor, no keyboard, no mouse).

For this setup, you will use Raspberry PI OS Lite version. Please refer to Raspberry PI OS Lite installation tutorial for complete procedure.

Check hardware prices with following links:

Amazon raspberry pi boards box
Amazon Micro SD box
Amazon Raspberry PI Power Supply box

Desktop OS Meaning

You can get a complete desktop computer with Raspberry PI using, beside micro SD card and power supply, also a USB keyboard (with touchpad or USB mouse) and monitor. In this configuration, a network (Wi-Fi or wired) is desiderable for connecting internet resources.

With those pieces, you can setup the so called “Desktop installation”. This means that you will completely manage your Raspberry PI locally with its attached monitor and keyboard.

For this setup, you will use Raspberry PI OS Desktop version. Please refer to Raspberry PI OS Desktop installation tutorial for complete procedure.

Check hardware prices with following links:

Amazon raspberry pi boards box
Amazon Micro SD box
Amazon Raspberry PI Power Supply box
Amazon USB Wireless Keyboard box
Amazon HDMI Cable box

For a deeper comparison between lite and desktop distributions, please refer to Raspberry PI OS Lite vs Desktop guide

Raspberry PI Usages

Raspberry PI is a very versatile board.

…for DIYers

Its built-in GPIO pins allows makers and DIYers to develop intelligent programs which react based on external world inputs or interact with it. Common usage is managing robots, rs components, peripherals. For this purposes, the low cost and low power consumption PI Zero W can be the best choice when low CPU (SoC), RAM and GPU usage is required. Pi Zero W also performs very fine with python programming language.

…for Programming

It software universe and wide community make it a special opportunity for educators and kids (and people less young…) wanting to teach / understand programming basics. This blog (peppe8o.com) and the same Raspberry PI official website (maintained by Raspberry PI Foundation) are plenty of python scripts, as well as scratch, java, javascript, C languages are widespread. MagPI (official Raspberry PI Foundation free magazine) includes also many resources from hobbyists all around the world, which share their inspiring projects with all passionates. PI can also run complex programs, so it is sometimes also used by industries in their products.

…for Linux Systems

Don’t forget that Raspberry PI has Linux in its heart. So a long list of Linux distributions and open source software can run on Raspberry PI making it a little but powerful server. Ethernet connections in Model B series (upgraded to Gigabit ethernet in PI 4) grants enough speed to communicate fastly with world. In these projects high speed SD cards can improve performances when output requires strong workload. A typical usage is in media center (kodi), home automation, retro games emulator (retropie), and many others up to havig your minecraft server!

…for Home Computer

Last but not least, Raspberry PI can be also a very small personal computer, which you can also bring with you or give it to your kids for starting computer knowledge. Connect hdmi cable to your monitor or TV (please check hdmi type in Raspberry PI boards comparison article before shopping), a keyboard and mouse and you will get a powerful but cheap computer.

best Raspberry PI projects article and peppe8o home page include tons of tested projects with detailed tutorials. You can also check a list of alternative operating system distributions in What Raspberry PI OS (Operating System) to use article.

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