Raspberry Pi or, as it is called on the Russian-speaking Internet, "raspberry", "raspberry pie", "raspberry pie" is a microcomputer that has become widespread in Russia and around the world. It is used by home craftsmen and experienced professionals as a replacement for a desktop computer and as the basis of a "smart home" for watching videos, automating watering of vegetables in a greenhouse, creating robots and many other tasks. There are quite a few varieties of Raspberry Pi, and the number of devices connected to it is difficult to enumerate.
What is Raspberry Pi
The Raspberry Pi is a tiny but complete computer. According to its external features, it can be attributed to the so-called. embedded or single board computers, i.e. computers intended for use as part of any product: cars, game consoles, industrial and medical equipment, smart home, Internet of Things devices, etc. Unlike microcontrollers such as the Arduino, the Raspberry Pi has a complete operating system, so it is capable of much more complex tasks.
Raspberry Pi is a trademark of the Raspberry Pi Foundation.
What are the Raspberry Pi
Raspberry Pi computers have been on sale since 2012, and quite a few varieties have been released during that time. Below we will take a closer look at modern samples, and we will list the older models briefly.
Raspberry Pi 3 model B
This variety was released in February 2016. Here are its main technical characteristics:
- processor (CPU): 64-bit 4-core ARM, 1.2 GHz;
- random access memory (RAM): 1 GB;
- size: 85, 6x56, 5x17 mm.
The possibilities for interacting with the outside world of this computer are very impressive:
- full size HDMI video output;
- 4 full-size USB connectors;
- audio output;
- Ethernet connector for wired LAN connection;
- Wi-Fi for wireless LAN connection;
- Bluetooth;
- microSD card slot;
- General purpose input-output connector (so-called GPIO);
- camera connector (CSI);
- display connector (DSI) incl. supports touch sensitive screens, so-called. touchscreens.
Please note that the Raspberry Pi 3 model B board lacks onboard flash. To start this single board computer, you need to take a microSD memory card, write an image of the operating system to it, and insert it into the slot on the board.
Also, a feature of the Raspberry Pi 3 model B is the use of a micro-USB connector to connect the power supply, as in modern cell phones. However, it should be borne in mind that not every phone charge is suitable for powering "raspberries" For example, to power the Raspberry Pi 3 model B, the manufacturer recommends using a power supply from a reliable manufacturer rated for up to 2.5A.
Raspberry Pi 3 Zero and Zero W
These are special variants of the Raspberry Pi with reduced size and, accordingly, power. The Zero 3 was released in May 2016, and the Zero W in February 2017. They are designed for applications where the high performance of the older model is not required, but small size and low power consumption are of great importance.
Here are the main specifications for these samples:
- processor (CPU): 1 GHz 32-bit 1-core ARM;
- random access memory (RAM): 512 MB;
- size: 65x30x5 mm.
The possibilities for connecting external devices are more modest here:
- mini HDMI video output;
- 1 micro-USB connector;
- microSD card slot;
- General Purpose Input / Output (GPIO) connector
- camera connector (CSI).
Zero W differs from just Zero in that it has Wi-Fi and Bluetooth. Both boards are powered via a micro-USB connector. Thus, there are 2 micro-USB connectors, one of which is used only for connecting power, and the other for connecting external devices.
Please note: like its older brother, the Raspberry Pi 3 model B, these variants lack onboard flash memory. To start this single board computer, you need to take a microSD memory card, write an image of the operating system to it, and insert it into the slot on the board.
Raspberry Pi 3 Compute Module
This is the so-called. Compute Node - A type of Raspberry Pi specifically designed to be used as part of an industrial product. The power of this embedded computer is the same as that of the Raspberry Pi 3 model B, and the dimensions are close to the Zero variety:
- processor (CPU): 64-bit 4-core ARM, 1.2 GHz;
- random access memory (RAM): 1 GB;
- size: 67, 6x31 mm.
The main differences from the previously considered varieties are as follows:
- all connectors are assembled into one large 200-pin SO-DIMM connector located along the edge of the board;
- no Wi-Fi, Bluetooth and Ethernet;
- has a built-in flash memory of 4 GB.
To use this assembly, it must be inserted into a dedicated motherboard with an SO-DIMM socket. Through this connector, the node receives power and interacts with the product of which it is a part, for example, a car, a CNC machine, a drone, etc.
The question may arise: why do you need a computing node if you already have a Raspberry Pi 3 model B and Zero? The answer is simple: firstly, Zero is still a relatively weak computer in terms of power; and the Raspberry Pi 3 model B is aimed mainly at handy craftsmen, for whom some redundancy in size and connectors is quite acceptable. In the case of professional use of the Raspberry Pi, unused connectors are unacceptable, even if they are hidden under the casing. Agree, it will be very strange if someone discovers a camera connector or a pair of hidden USB ports inside, say, a home entertainment system.
There is also a lightweight version of the computing node: it differs from the complete absence of built-in flash memory.
Previous Raspberry Pi samples
Of the varieties of the "raspberry pie" of the past years of development, the Raspberry Pi 2 model B is perhaps the most widespread:
It is only slightly inferior in performance to its 3rd generation older brother, and it has the same dimensions, connectors and wireless connectivity.
The first version of the Raspberry Pi Zero, released in November 2015, differs from the modern ones in the absence of a connector for connecting a camera.
A feature of the very first samples of the Raspberry Pi model B, produced in 2012 and 2013, was the presence of an analog RCA video output, the so-called. Tulip, and fewer USB ports:
Also, those Raspberry Pi samples had a shorter GPIO connector and consisted of only 26 pins. However, backward compatibility is preserved: expansion boards, released for those Raspberry Pi, can be connected without any alterations to the first 26 pins of the GPIO connector of modern "raspberries", in which this connector has 40 pins. Moreover, many modern expansion boards connected to the Raspberry Pi GPIO can work successfully when those very first examples of an embedded computer are connected to the I / O connector.
There was also a variant of the Raspberry Pi 1 model A, which was the younger brother of model B: it had only 1 USB connector, and there was no Ethernet connector.
All 1st generation Raspberry Pi samples lacked built-in wireless connectivity capabilities like Wi-Fi and Bluetooth. However, it was possible to connect the corresponding devices to them via the USB connector.
What can be done with a Raspberry Pi
It can be said simply: if a problem is solved using a computer or microcontroller, it can be successfully and, as a rule, cheaply solved using a Raspberry Pi!
As with any computer, the capabilities of the Raspberry Pi are determined not only by hardware, ie. the capabilities of the devices soldered on the single-board board and connected to it, but also by "software", i.e. software. The basis of the software of any computer is the operating system. The Raspberry Pi can run many different operating systems, but the main operating system for it is Raspbian. We advise you to use it in the overwhelming majority of cases, because it is designed specifically for the Raspberry Pi.
So what can be done with this single board computer? Let's start with some simple, superficial examples:
- The Raspberry Pi 3 model B will successfully replace a working computer: insert an SD card with the recorded image of the Raspbian operating system into it, connect a keyboard and mouse to it via USB connectors or Bluetooth, and a monitor via HDMI - and here you are! The Raspbian OS is quite modern. After launching it, the user gets to the familiar graphical desktop. The OS has a Chromium web browser, a set of LibreOffice office applications and an email application. You can connect a computer to a local network at work or at home either with a wire through the Ethernet connector or over the radio using Wi-Fi.
- The Raspberry Pi 3 model B is perfect for a student's personal computer. In addition to the already mentioned Internet browser and office applications, it has opportunities for learning programming in Scratch, Python, Perl, C / C ++, JavaScript. You can do math with the Wolfram Mathematica app, and you can also write electronic music with the Sonic Pi.
A huge number of other applications are available for installation on demand for all occasions.
Less obvious, but also very common examples of using the Raspberry Pi:
- a multimedia entertainment center such as Kodi;
- "Digital signage": a video player for a monitor located in any public place: a store, school, university, clinic, shop window, etc.;
- photo kiosk.
Further, if you are ready to work with your hands, you can do it yourself based on the Raspberry Pi:
- notebook;
- webcam;
- camera for time-lapse video recording;
- Wi-Fi router;
- voice assistant like Yandex. Station;
- automatic telephone exchange (automatic telephone exchange);
- weather information display;
- electronic dashboard for the car;
- a cat door that recognizes your pet and lets only him in;
- cheap night vision goggles;
- and many many others.
If you are attracted to robots, you can build your own Raspberry Pi robot:
- simple 2-wheeled car;
- the same car that can drive along the drawn line;
- remote control machine;
- L3-37 from Star Wars;
- etc.
Connecting devices to the Raspberry Pi
Household connectors and wireless connections
You can connect a TV, monitor or video projector to the HDMI video output. There is also an analog video output. To receive a signal from it, you must use a special wire connected to the 3.5 mm audio output.
Any USB device can be connected to the USB connector of the Raspberry Pi, provided that the driver for it is loaded in the operating system under which the single-board computer is running. Typically, common devices such as keyboards, mice, flash drives and external hard drives work out of the box. But connecting a 3G / 4G modem or TV receiver may require manual installation of drivers. A partial list of devices that work with the Raspberry Pi can be viewed at eLinux.org.
The audio output is a regular 3.5 mm jack, you can connect headphones or wired speakers with an amplifier to it.
Bluetooth: you can connect headsets, wireless speakers and many other devices; you can connect a smartphone and control your single board computer from it.
Wi-Fi: The Raspberry Pi can act as a slave device, the so-called. client of the Wi-Fi network, and as a presenter, the so-called Wi-Fi hotspot.
Camera and screen
The Raspberry Pi 3 model B and Zero have a dedicated camera connector. Cameras are available with a resolution of 5 and 8 megapixels, with and without an infrared filter, with a fixed or variable focal length, for day or night photography - the choice is huge, and will satisfy the needs of most users.
The same is the case with screens: LCD screens are available in various sizes and resolutions, including those supporting 10-point touch, color, monochrome and black and white. There are also e-paper screens, which are good for applications where the image is not refreshed frequently. Curiously, the screens for the Raspberry Pi are connected not only via the DSI connector, but also via the GPIO, HDMI and USB connectors.
Expansion boards
The highlight of the Raspberry Pi is the GPIO - a 40-pin general purpose I / O connector:
Expansion boards (HAT, English hardware on top) can be connected to it, which add new features to the embedded computer. The convenience of using such a board is that you do not need to solder or carefully connect the GPIO pins and the connected board one by one with jumpers. All connector pins have a specific purpose; just align the connector on the Raspberry Pi with the counterpart on the plug-in board, press - and you're done! It should be noted, however, that the assignment of some of the GPIO pins can be changed. If this is the case, check the manual for the plug-in board to see if it will work with the remapped pins.
This is how, for example, a Raspberry Pi 3 model B looks like with the Sense HAT board connected:
The choice of expansion cards is truly huge. Here is a far from complete list of their types:
- LEDs and their grids;
- LED (OLED), LCD (TFT), segment screens;
- small loudspeakers, buzzers (buzzers);
- microphones;
- sound cards, sound amplifiers;
- buttons, keys, joysticks;
- receivers and emitters of infrared radiation;
- GPS / GLONASS signal receivers;
- NFC / RFID, LPWAN, XBee, Z-wave transceivers;
- GSM 2G / 3G / 4G modems;
- contactors (relays);
- digital-to-analog and analog-to-digital converters;
- uninterruptible power supplies;
- control boards for electric motors and servo drives;
- etc.
It is also a great convenience that several expansion boards can be connected to the Raspberry Pi GPIO at the same time. It turns out something like a whatnot or a puff cake. Of course, when connecting multiple expansion boards to the Raspberry Pi general-purpose I / O connector, you need to consider which GPIO pins each board uses and how so that the boards do not interfere with each other.
Sensors
You can connect sensors to the Raspberry Pi, probably for anything you can imagine:
- heating air, liquid, soil;
- humidity of air, soil;
- illumination;
- infrared, ultraviolet radiation;
- air pressure;
- movement;
- shock, shaking;
- acceleration;
- touch;
- wind speed and direction;
- tilt;
- distances;
- directions to the cardinal points (compass);
- smoke;
- gases: oxygen, carbon dioxide, carbon monoxide, NO2, hydrogen, methane, household, alcohol vapors, etc.;
- palpitations;
- Hall Sensor;
- magnetic field;
- current strength;
- fluid consumption;
- and etc.
Sensors can be both digital and analog. The connection method for each sensor is different. Some connect directly to the general purpose input / output (GPIO) connector, while others connect to a special expansion card or USB connector. Some sensors may require simple radio components such as resistors to connect. Depending on the connection method, it is possible to connect only one sensor to one Raspberry Pi or many at once, both of the same type or different.
Features of buying a Raspberry Pi
If you are going to buy this single board computer, consider the following features:
MicroSD memory card
Raspberry Pi, except for the Compute Module variety, does not have built-in persistent (flash) memory. This memory will contain an image of the operating system, application software, and the data necessary for their operation. Therefore, you will also need to buy a microSD card. The capacity of 4 GB is sufficient for basic applications, but we recommend using a card with a size of 8 GB or more.
Source of power
The Raspberry Pi is sold without a power supply. The power supply should be equipped with a micro-USB connector, as is the case with modern cell phone power supplies. However, keep in mind that not every phone charger is suitable for powering the Raspberry Pi. For example, to power the Raspberry Pi 3 model B, the manufacturer recommends using a power supply from a reliable manufacturer rated for up to 2.5A. For the Zero variety, a weaker source can be used. Keep in mind that a lot depends on the number and power of the connected USB devices and expansion cards, as well as on whether you are using wireless data transfer via Wi-Fi or Bluetooth.
Frame
The Raspberry Pi is sold without a case. In some cases, you do not need a case if you are going to build this single-board computer into any product that has its own case. You can also make a case yourself from improvised items, or even print it on a 3D printer - on the Web you will find many ready-made 3D models of cases for "raspberries".
If your case does not apply to those listed above, then buy a case with the Raspberry Pi. Note that the Zero variant case will not fit the Raspberry Pi 3 model B. The converse may or may not be true - read the descriptions carefully. Also, when choosing a case, consider:
- whether you will connect expansion cards: this affects the height of the case;
- whether you will connect the camera: there are cases where there is already a place for installing the camera;
- whether you will connect the screen: there are cases where there is already a place for installing the screen;
- will you connect any external devices to the general purpose input / output (GPIO) connector of the Raspberry Pi, such as sensors, LEDs, buttons, screens, etc.: there are enclosures with slots for wires going to the connector GPIO.
Real time clock
The Raspberry Pi does not have a built-in real-time clock. This means that every time the power is turned off, the clock stops. For some Raspberry Pi applications, it doesn't matter. In case, for your case, the exact time on the computer is necessary, consider the following options:
- each time after switching on, set the time manually. This is the most inconvenient way;
- configure a permanent connection of the Raspberry Pi to the Internet via Wi-Fi, Ethernet, 2G / 3G / 4G GSM modem or Bluetooth. In this case, a few minutes after starting the Raspberry Pi and establishing a connection to the Internet, the clock will be automatically set to the correct value;
- buy and install a special expansion card, for example, RasClock, on which a real-time clock and a battery are located;
- buy and install a custom expansion board like the UPS Pico that will act as an uninterruptible power supply for your Raspberry Pi. A rechargeable battery is connected to such a board, which will power your embedded computer while electricity is not available from the mains power source.
Raspberry Pi as a home or work computer
If you are looking to buy a Raspberry Pi to use as a work or home computer, you will also need:
- keyboard connected via USB or Bluetooth;
- mouse connected via USB or Bluetooth;
- monitor or TV with HDMI or DVI connection, in the latter case, you will also need an HDMI to DVI adapter.
Optional accessories
As a rule, in the stores where you can buy Raspberry Pi, various additional devices and accessories are also sold: expansion boards, sensors, cameras, screens, connecting wires, jumpers, etc. Don't forget to buy these accessories along with your Raspberry Pi.
Installing an operating system on a Raspberry Pi 3
Choosing operating systems for the Raspberry Pi 3
The complete list of operating systems that can be installed on the Raspberry Pi 3, and in most cases on older varieties of "raspberry", has several dozen pieces. Typically these are Linux kernel based OSs such as Raspbian, Ubuntu, LibreELEC, and OSMC. You can also install a special edition of Windows 10 - IoT Core. Of course, it is impossible to consider the installation of all supported operating systems in one article. We will limit ourselves to describing the installation of the main OS designed for the Raspberry Pi - the Raspbian OS, then we will talk about installing Windows 10 IoT Core and, finally, about installing the Kodi media center.
You will need
- Raspberry Pi 3 model B, Zero, or another variation of this microcomputer;
- microSD card 8 GB or larger;
- power supply for "raspberries";
- USB keyboard;
- USB mouse;
- monitor connected via HDMI-connector;
- another computer equipped with a microSD card reader and writer.
This is the magic word NOOBS
NOOBS stands for New Out Of Box Software, which can be translated into Russian as "installation software". This is the same as, for example, an installation DVD or an installation flash drive with a Windows 10 or Linux operating system for a personal computer. Typically, OS installation from a DVD or USB flash drive is performed on the computer's hard drive, and the installation media itself does not change. In the case of NOOBS for Raspberry Pi 3, it is done differently: you write the NOOBS installation software to the memory card, insert it into the "raspberry", turn it on and get into the installer. After it finishes working, the operating system of your choice will be installed on the flash card instead of NOOBS.
Note that this is not the only way to install the OS on the Raspberry Pi 3. However, for novice users, we recommend using it: it is the easiest.
The following operating systems can be installed on a microcomputer using NOOBS:
- Raspbian,
- Windows 10 IoT Core,
- LibreELEC and OSMC are operating systems for the Kodi media center.
It is possible to install several other operating systems using NOOBS, but their consideration is beyond the scope of this article.
Installing Raspbian on Raspberry Pi 3
To install the Raspbian operating system on a Raspberry Pi using NOOBS, follow the steps below:
- download the SD Memory Card Formatter application from the SD Association network node;
- insert the memory card to which you want to write the Raspbian image into the microSD card reader and writer;
- format the memory card with it;
- go to the NOOBS subsection of the Downloads section of the Raspberry Pi Foundation network node and download the NOOBS installation software as a.zip archive. The approximate file size is 1.2 GB;
- copy the contents of the.zip archive to a flash drive. Please note: the contents of the.zip file must be placed in the root of the map;
- safely remove the memory card;
- insert the microSD card into the "raspberry", connect the keyboard and mouse to the USB connectors, connect the monitor via the HDMI connector and the power supply;
- plug the microcomputer power supply into an outlet and wait for the NOOBS installation software to load;
- in the list that appears, select the Raspbian operating system;
- run the installation and wait for it to complete. After rebooting the Raspberry Pi 3, the Raspbian OS will boot.
Please note: if you are using a memory card with a size of 64 GB or more, after performing step 3, the card will contain, as it should, a single partition, but it will be formatted in the exFAT file system, which the microcomputer bootloader does not understand. In this case, after step 3, you need to use another application to format the only partition on the flash card to the FAT32 file system. If the computer on which you are preparing a memory card for the "raspberry" is running Linux or MacOS, use the standard tools. On Windows, the built-in formatting utility will not work, so you will have to use a third-party application such as the FAT32 format GUI from RidgeCrop Consultants.
You can also install Raspbian on a Raspberry Pi using direct upload to a microSD card. An image of a memory card, on which Raspbian is already installed, is taken, and directly sector-by-sector written to a new card. At the same time, there is no need for its preliminary formatting: the required set of partitions and the file system are already in the original image.
This method is suitable for more experienced users. This is especially convenient if you need to prepare several Raspberry Pi 3s at once with the same operating system and the same set of application software.
Next, we'll take a look at installing pure Raspbian on raspberries as an example. Proceed according to the steps below:
- go to the Raspbian subsection of the Downloads section of the Raspberry Pi Foundation network site and download Raspbian Stretch with desktop or Raspbian Stretch Lite as a.zip archive. The approximate file size is 1300 MB in the former case and 350 MB in the latter;
- extract the OS image file from the downloaded.zip archive to an arbitrary folder on the disk. This file usually has the extension.img;
- download and install the Etcher application designed for low-level recording of operating system images to a flash card;
- insert the memory card to which you want to write the Raspbian image into the microSD card reader and writer;
- start Etcher, specify the drive letter corresponding to your memory card, specify the path to the.img file with the Raspbian operating system image and start recording;
- after the end of the recording, insert the memory card into the Raspberry Pi 3, connect the keyboard and mouse to the USB connectors, connect the monitor via the HDMI connector and the power supply;
- Plug the microcomputer power supply into an outlet and wait for the Raspbian operating system to boot.
The great convenience is that the Etcher application is supported on all major operating systems: Windows, Linux and MacOS.
Installing Windows 10 on Raspberry Pi 3
To install Windows 10 IoT Core on Raspberries using NOOBS, you need to proceed in a manner similar to installing Raspbian using NOOBS. The only difference is that in step 9, when the choice of operating systems to install appears, you need to select Windows 10 IoT Core.
You can also install Windows 10 using direct upload to microSD card. This method is convenient because it is faster than installing through NOOBS. In addition, you can quickly prepare several identical memory cards, for example, if you are going to conduct a practical lesson on Windows 10 IoT Core or if you need to ship many embedded computers with a pre-installed OS and a single set of applications to the customer at once.
Microsoft has taken care of the user experience and released a special application that makes things easier. Proceed as follows:
- download the Windows 10 IoT Core Dashboard application from the Microsoft network node, install it and launch it;
- insert the memory card to which you want to write the image of the operating system into the device for reading and writing microSD cards;
- in the IoT Core Dashboard window, specify values for the Device type fields ("Device type", for example, "Raspberry Pi 2 & 3"), OS Build (Windows 10 build number), Drive (drive letter corresponding to the memory card), Device name (the network name of the microcomputer running Windows 10), New Administrator password (administrator password), Confirm Administrator password (again the administrator password);
- if you want the prepared Raspberry Pi running Windows 10, after launch, to independently connect to a Wi-Fi network known to your computer, check the Wi-Fi Network Connection checkbox and select a Wi-Fi network from the list;
- check the I accept the software license terms checkbox and click Download and install. The IoT Core Dashboard will automatically download the desired Windows 10 image and write it to the microSD card.
It should be noted, however, that the IoT Core Dashboard application only works on the Windows operating system, so it will not work for macOS and Linux users.
Installing Kodi Media Center on Raspberry Pi 3
Kodi is an advanced free media player with a user-friendly interface. It is for its high quality and prevalence that the creators of the Raspberry Pi included it in the NOOBS installation application. Generally speaking, Kodi can be installed on a Raspberry Pi 3 as a Raspbian app. However, this is not the most convenient and reliable solution. It is better to use the operating system LibreELEC or OSMC, which contain only Kodi and the libraries necessary for it to work.
To install Kodi, proceed in the same way as installing the Raspbian OS using NOOBS. The only difference is that in step 9, when the choice of operating systems to install appears, you need to select LibreELEC or OSMC.
Installing an OS on a Raspberry Pi 3 for the lazy
If you are too lazy or have no time to independently record the NOOBS installation software on a memory card, you can buy it with the already recorded NOOBS. For the price, it hardly differs from an empty card. An added benefit of this approach is that such a card is likely to be compatible with this microcomputer.
Raspberry Pi 3 model B +: new in 2018
The Raspberry Pi is evolving quite quickly, and every year the developers release something new. The most significant innovation of 2018 for today was, of course, the release of a new version of this single-board computer - Raspberry Pi 3 model B +:
According to a note on the Raspberry Pi Foundation website, here are its main differences from the previous version of the single board:
- processor frequency increased from 1.2 to 1.4 GHz;
- 2-band Wi-Fi 802.11ac;
- the speed of the wired Ethernet connection has been increased from 100 to 300 Mbit / s;
- more advanced bluetooth version 4.2.
There are also a number of minor improvements.
That's all there is to it about this amazing embedded computer. Enjoy your Raspberry Pi!
