Raspberry Pi is a credit-card-sized single-board computer developed by Raspberry Pi Foundation. It was developed as a low-cost microcomputer to impart computer skills to school children. It comes without any power supply or peripherals, and it is supposed to be programmed in Python — the reason for the ‘Pi’ in its name.
Raspberry Pi (RPi) is not the only single-board computer, although it is definitely the most popular one right now. It comes packed with a powerful ARM processor, Ethernet, onboard Wi-Fi and Bluetooth, HDMI ports, DSI display port, CSI camera port, stereo audio, and composite video port, USB ports, and 40-pin GPIO header. It can run any Debian-based Linux distribution and is an all-in-one package that can be used for desktop programming, networking, web development, internet of things, embedded systems programming, robotics, automation, and anything that falls within a desktop, server, or embedded domain. RPi has put the power of computing into the hands of masses by offering a cross-platform-capable computing machine at an extremely affordable price tag.
The RPi can run Linux, Windows, and even Android. As far as programming languages are concerned, it is also not limited to Python but can take advantage of C and Java, as well. The availability of a 40-pin general-purpose input-output header that includes I2C and SPI interfaces makes it an ideal machine to be used for embedded programming backed by a Linux (or other) operating system.
What can Raspberry Pi be used for?
Raspberry Pi is a low-power microcomputer built on a single board. Its processor, GPU, RAM, and input/output peripherals are all built on a single board. It is a general-purpose computing device designed with a unique choice of hardware features such that it can be employed to multiple applications. These applications are independent of any computing domain (desktop, mobile, server, or embedded) or choice of operating system or programming language.
It is possible to run any Debian0-based Linux distribution on the RPi board. So, it can be used to exploit Linux and its internals like shell scripting or Linux system administration. It can even host Windows and Android operating systems. So for operating systems, RPi can be taken as a low-cost test machine for system programming and administration. Any programming language can be used for application development on RPi provided it is supported by the operating system running on it. This freedom to program in any language opens limitless possibilities of programming different types of apps on Raspberry Pi. Any general-purpose application on any programming language can be developed on an RPi computer.
The RPi comes with HDMI ports, USB ports, and DSI display port with an onboard processor, RAM, and GPU, so it can be utilized for any desktop programming task. With a 40-pin GPIO header, RPi can even be used to connect with parallel computer bus interfaces. Given stereo audio and composite video port, HDMI ports, and DSI display port, RPi can be used to develop several multimedia applications, gaming, and home theatre PC. The availability of Ethernet, Bluetooth, BLE, and Wi-Fi on the board makes it capable to program network applications. The RPi can itself be used as a low-profile web server.
The 40-pin GPIO header (of which 28 are available) on this tiny RPi board can be used to interface sensors and actuators so that it can be efficiently utilized for embedded systems programming, robotics, and automation. The advantage of using RPi for embedded systems is that it will have an operating system running on it so it appropriate for complex embedded applications that may need sophisticated software at their back. And yes, embedded scripts or apps running on it can be easily upgraded or can be developed to upgrade time and again through an internet connection.
It is even possible to run Android on the Raspberry Pi so that it can be used for the development of some Android-specific applications. The programmers and developers have used Raspberry Pi for cluster computing, artificial intelligence, scientific computing, supercomputing, web development, and the Internet of Things. This is a small and powerful computer that can be used for a variety of multi-platform purposes until and unless its processor hits its limits.
It is possible to run any Debian-based Linux distribution on Raspberry Pi. Raspbian is the official Linux distribution for RPi that is developed and maintained by Raspberry Pi Foundation. The popular Linux distributions that can be run on RPi include Ubuntu, Kali Linux, CentOS, Arch Linux ARM, Gentoo, openSUSE, OSMC, OpenMediaVault, Recalbox, RetroPie, Lakka and many others. It is also possible to run Windows or Android on the RPi board.
Raspberry Pi offers a number of benefits as a computing platform including the following:
Size – It is a single-board computer of the size of a palm. With such a small size, it can easily fit any creative use.
Computing – The latest RPi board (RPI 4) has 1.5 GHz Quad-core Cortex-A72 (ARM v8) 64-bit SoC combined with up to 4GB LPDDR4-3200 SDRAM. Raspberry Pi 4 can also run dual displays in 4K at 60 FPS. Remember, this is a lot of computing power in a credit card-sized computer.
Networking – Raspberry Pi 4 has Gigabit Ethernet port, 2.4 GHz and 5.0 GHz IEEE 802.11ac wireless (Wi-Fi), Bluetooth 5.0 and BLE. These hardware features make RPi suitable for fast internet applications and an ideal choice for IoT.
Interfaces – RPi is equipped with I2C, SPI, UART, and Xbee socket. Its GPIO pins can also be utilized to communicate data with other computer buses and communication protocols.
GPU – Raspberry Pi comes with a dedicated GPU for image processing. The board is designed with Broadcom VideoCore VI that supports OpenGL ES 3.0 graphics. RPi 4 also has two 4kp60 HDMI ports for dual display. Raspberry Pi has sufficient support for games, graphics, and 3D modeling.
GPIO – The 40-pin GPIO header can be used to design various embedded applications. This number of GPIO pins is even not available in many popular microcontroller boards. However, all these GPIO pins are digital. There is no analog input pin.
Raspberry Pi can be a good choice as far as programming, learning, or prototyping is concerned. But it may not be the best choice for a commercial application. It is capable of providing full-fledged desktop experience, and as an embedded computer, it’s quite good on specifications; however, designing it into a product may not be as wise.
First of all, RPi runs an operating system on an SD card and lacks flash memory. So, its operating system is always prone to data corruption. It also does not have features such as a built-in ADC or RTC that are often used in embedded systems. It has only one UART, and only 28 GPIO pins of it are unreserved. Another hurdle in using RPi for some commercial applications is its USB micro-connector based power supply. Form factor and heat management can be an issue in using RPi for some applications. The RPI is even not equipped with any reverse voltage or over voltage protection. Its long-term availability and scalability pose another challenge in using it for something salable. Obviously, like any computing machine, RPi, too, faces benchmark limitations.
As Raspberry Pi is not designed for commercial use, it has several practical limitations on that side. Still, it is an excellent machine to start learning emerging computer technologies, programming Linux-based desktop and embedded applications, and prototyping. Prototyping, in this case, should be limited to using Linux, another operating system, or a programming language to develop desktop, web, IoT, or embedded applications. There is no compatible board to RPi where your codes or circuits can be transferred as it is. There are compute modules available and still have similar drawbacks.
Raspberry Pi alternatives
Fortunately, Raspberry Pi is not the only single-board computer. Many other single board computers have equivalent or better specifications. Some of the popular Raspberry Pi alternatives include Banana Pi M64, Pine A64, Orange Pi, Rock64 Media Board, Onion Omega2Plus, PocketBeagle, Le Potata, Odroid-C2, Rock Pi 4, Asus Tinker Board S, Beagleboard X15, etc. Some of these boards even have on-board flash memory or eMMC (embedded multi-media controller) that makes them suitable to use for commercial applications. However, these SBCs may not have as much community support and development support and may also not be as easily and widely available as the most popular Raspberry Pi.
In the next tutorial, we will discuss various Raspberry Pi models. We will take a look at their specifications, cost, and evolution. Stay connected; a joyride is about to begin.