Raspberry Pi Coding & Projects The Complete Manual -julkaisun Issue 7 -irtonumeron sisällysluettelo

The Raspberry Pi is a British built low cost computer that enables everybody to learn computing, start programming and explore basic electronics. It’s the size of a credit card but capable of running a full operating system and doing everything a desktop does. More importantly, with the Raspberry Pi you install your own operating system, connect all your devices and create your own programs using languages like Scratch and Python. There’s no case so you can hook up electronic circuits to the pins and control them to get input and output, so you can hack together electronic projects at home. Setting up a Raspberry Pi is pretty simple, and throughout this book we’ll take you step-by step from unboxing your Raspberry Pi to setting it up and getting started. There…

The Raspberry Pi 5 has totally changed the game! There are two versions, one with 4GB and one with 8GB of RAM. The processor is a quadcore Arm Cortex-A76 running at 2.4GHz, which is faster than the chip in the Raspberry Pi 4. And guess what? There’s a power button on the board! No more fiddling with the mains or pulling the power lead out of the USB-C socket. Just press a button and you’re good to go. The button is on the front of the computer, opposite the Ethernet and USB ports. So, if you have an old Raspberry Pi 4 case, you’ll need to get a new one that’s specifically designed for the Pi 5. The Raspberry Pi Foundation already sells them, and other companies will probably make…

EVERYONE LOVES PI We’ve put together ten possible projects that you could use your Pi 500 or your classic 400 with; that will entertain and keep you busy while helping you learn more about coding, the Pi and computing. RETRO COMPUTING With the Pi 400 being very similar to that of the great home computers of the 80s, we thought we’d start these ideas with a simple retro-themed project. Fuse is a ZX Spectrum emulator that’s available for the Raspberry Pi. Install it, and you can enjoy some of the greatest games ever created. STREAM PC GAMES It’s possible to stream any game installed on your powerful gaming PC to a Raspberry Pi. All you need is to ensure that your home network is up to scratch – use Ethernet…

The Pico uses MicroPython or C/C++ code in order to communicate with the devices it will be attached to. The code will, when uploaded to the Pico, run a specific set of instructions depending on the electronics that are soldered to the Pico. For example, in MicroPython, with an LED attached to the Pico, you would initialise and import the Pin and Timer modules, tell the Pico which GPIO the LED is attached to, then setup a routine that will use the Timer function to send a signal to the LED – let’s say every couple of seconds. The end result would be a blinking LED, which goes on and off every two seconds. Naturally, the more complex the electronics attached to the Pico are, then the more complex the…

STEP 1 Connect your Raspberry Pi to the monitor using the HDMI cable. Now attach the keyboard and mouse to separate USB ports. If your Raspberry Pi only has one USB port, connect the mouse and keyboard to the USB hub and attach it. STEP 2 Now, if required, connect the Ethernet cable to the Raspberry Pi. Connect the other end of the cable directly into your modem/router or into a network socket. STEP 3 Finally connect a Micro USB cable to the power supply and attach the other end to a 5V USB power adapter. This is the type used to power most modern smartphones, so you should be able to source a spare. Press the On button to power up your Raspberry Pi. STEP 4 Consider a case…

STEP 1 A NOOBS folder should appear in your downloads. It will be marked with the version number that you downloaded from the Raspberry Pi Downloads web site. Double click the NOOBS zip file in your Downloads folder to view the contents. These are the files you need to copy to the root (base) of your SD Card. STEP 2 Click Extract All to expand the zipped file and extract its contents. Click Browse in the Select a Destination and Extract Files folder and choose “SD Card(F:)” in the Select a Destination window. Click Select Folder and Extract. The files will now be copied directly from the zip file to your SD Card. STEP 3 Wait for all of the files to be copied from your Downloads folder to the…

USING TERMINAL Despite its graphical PIXEL interface, Raspberry Pi OS is a Linux operating system and this means you’ll spend a lot of time working with text commands. Using the command line is an important part of learning to use a Raspberry Pi computer. STEP 1 By default the Raspberry Pi boots directly into the PIXEL interface. Here you use a visual metaphor, files, buttons and so on, to make changes to your computer. The command line is where you control a computer by entering text commands. Click Terminal in the Menu bar to view the console. STEP 2 You can enter commands into the Terminal to make changes to the computer. This works alongside the PIXEL interface. Enter: mkdir Desktop/testfolder and press return. Notice a new folder appears below…

REMOTE CONTROL The Raspberry Pi is easy to set up and use in projects around the home and, surprisingly, many of these projects don’t need a keyboard, mouse or a monitor; these are known as Headless devices. VNC lets you control a Headless Pi from another computer. STEP 1 You will first need to ensure that your Pi is connected to a keyboard, mouse and monitor, and is connected to your Wi-Fi router, before you attempt to connect to it remotely. Start by clicking on the Raspberry Pi menu, then scroll down to Preferences > Raspberry Pi Configuration. STEP 2 With the Raspberry Pi Configuration window open, click on the Interfaces tab, and ensure that the VNC option is Enabled. Click on the radio button next to Enabled to activate,…

VIEWING AND MOVING FILES You can move, manage and delete files using the Command Line but like all modern operating systems Raspberry Pi OS has a program to help you manage your files. Discover how to use the File Manager app. STEP 1 Raspberry Pi OS includes a great file management program called “File Manager PCManFM” or just “File Manager” for short. Click on the FileManager PCManFM icon in the Launch Bar or choose Menu > Accessories > File Manager. STEP 2 File Manager displays the folders in your Home folder (this should match your user name, ‘Pi’ by default). By default you should have Desktop, Documents, Downloads, Music, Pictures, Public, python_games, Scratch and folders. Double-click any folder to open it and view its contents. Click the Parent Folder icon…

EDITING CODE You will eventually reach a point where you have to move on from inputting single lines of code into the Shell. Instead, the IDLE Editor will allow you to save and execute your Python code. STEP 1 First, open the Python IDLE Shell and when it’s up, click on File > New File. This will open a new window with Untitled as its name. This is the Python IDLE Editor and within it you can enter the code needed to create your future programs. STEP 2 The IDLE Editor is, for all intents and purposes, a simple text editor with Python features, colour coding and so on; much in the same vein as Sublime. You enter code as you would within the Shell, so taking an example from…

FUNKY FUNCTIONS A function is a command that you enter into Python to do something. It’s a little piece of self-contained code that takes data, works on it and then returns the result. STEP 1 It’s not just data that a function works on. They can do all manner of useful things in Python, such as sort data, change items from one format to another and check the length or type of items. Basically, a function is a short word that’s followed by brackets. For example, len(), list() or type(). STEP 2 A function takes data, usually a variable, works on it depending on what the function is programmed to do and returns the end value. The data being worked on goes inside the brackets, so if you wanted to…

GOING GRAPHICAL You can draw simple graphics, lines, squares and so on, or you can use one of the many Python modules available, to bring out some spectacular effects. STEP 1 One of the best graphical modules to begin learning Python graphics is Turtle. The Turtle module is, as the name suggests, based on the turtle robots used in many schools, that can be programmed to draw something on a large piece of paper on the floor. The Turtle module can be imported with: import turtle. STEP 2 Let’s begin by drawing a simple circle. Start a New File, then enter the following code: As usual press F5 to save the code and execute it. A new window will now open up and the ‘Turtle’ will draw a circle. STEP…

LOOKING AT FILES Operating systems are built on files and folders, or directories if you prefer. While you’re used to viewing your own files, most operating systems keep other files out of sight. In Raspberry Pi OS, you have access to every file in the system. STEP 1 We’ve already looked at “ls”, which lists the files in the working directory, but you are more likely to use a command like “ls –l”. The bit after the command (the ‘-lah’) is known as the argument. This is an option that modifies the behaviour of the command. STEP 2 The “-l” argument lists files and directories in long format. Each file and directory is now on a single line, and before each file is a lot of text. First you’ll see…

MANAGING FILES AND DIRECTORIES Now that you know how to create files, you’ll want to learn how to make directories, which are the same thing as folders, as well as move items around. If you are more used to working with a desktop interface, this can take a bit of getting used to. STEP 1 Enter: ls to quickly view all the directories currently in in the home location. Directories are created using the “mkdir” command (make directory). Enter: mkdir testdir to create a new directory in your home directory. Enter: ls again to see it. STEP 2 The “mkdir” command is different to touch, in that it doesn’t update the timestamp if you use it with a directory that already exists. Enter: mkdir testdir again and you’ll get the…

HEY, MAN! The man pages are one of the best features of Linux, and as a built-in tool it’s invaluable for both beginner and senior level Linux administrators. Let’s see how it works STEP 1 Linux has a built-in manual, known as man for short. Using the man command you can obtain information on all the Linux commands we’ve talked about. Simply enter: man and the name of the command you want to learn more about. Start by entering: man ls in the command line. STEP 2 The man pages are a bit more detailed than you might be used to. First you have a name, which tells you what the command is called; in this case “list directory contents” and then the synopsis shows you how it works. In…

STEP 1 The root account is all-powerful. It is possible, but not recommended, to switch to the root account, although you’ll need to give it a password first (using “sudo passwd root”). Then just type “su” to switch to root. Please don’t do this though: knowledge is a good thing but it’s safer and wiser to use sudo instead. STEP 2 Most people think sudo stands for “super user”, but it stands for “substitute user do”. It enables you to perform a command as another user. Enter: sudo -u lucy touch/home/lucy/test to create a file inside the lucy home directory. You won’t get an error because the lucy user has permission to edit that directory. STEP 3 It’s rare that you use sudo to substitute another user. If you don’t…

TOP 10 COMMANDS These may not be the most common commands used by everyone but they will certainly feature frequently for many users of Linux and the command line. cd The ‘cd’ command is one of the commands you will use the most at the command line in Linux. It allows you to change your working directory. You use it to move around within the hierarchy of your file system. You can also use chdir. ls The ‘ls’ command shows you the files in your current directory. Used with certain options, it lets you see file sizes, when files where created and file permissions. For example, ls ~ shows you the files that are in your home directory. cp The ‘cp’ command is used to make copies of files and…

THE GOLDEN ERA OF CODE While it may seem a little counterproductive to learn how to code in a language that’s virtually obsolete, there are some surprising benefits to getting your hands dirty with a bit of retro coding. Firstly, learning old code will help you build the structure of code as, regardless of whether it is a language that was developed yesterday, or forty years ago, code still demands strict discipline to work correctly. Secondly, everyday coding elements, such as loops, sub routines and so on, are a great visual aid to learn in older code, especially BASIC. Lastly, it’s simply good fun. GOING BASIC The easiest retro language to play around with is, without doubt, BASIC. Developed back in the mid-sixties, BASIC (Beginner’s All-Purpose Symbolic Instruction Code) is…

Modern artificial intelligence (AI) coding tools go much further than checking your syntax, and helping you debug your programs. AI tools can analyse your entire code, offer suggestions of what to do next, work out where your program should go next and more. Don’t expect them to replace a good coder – they won’t write your code for you. But clever use of AI tools can greatly reduce the time it takes to complete your programs, by identifying problems so you can nip them in the bud and producing coding solutions that would take a human coder hours to write. But what are these tools? GITHUB COPILOT From free, https://github.com/features/copilot If you’re scratching your head wondering what to do next with your program, you can ask GitHub Copilot a question.…

FASTER AND CONNECTED There’s a lot to like about the Raspberry Pi 4: Up to 8GB of on-board memory, a faster quad-core CPU, support for dual 4K displays via a pair of micro-HDMI ports, and more. Let’s take a look at the Pi 4, and see what it’s got under-the-hood. PRICING Since the Raspberry Pi 4 now offers three different versions within the new model, it stands to reason that the pricing for it has changed slightly. The 1GB memory version of the Pi 4 is priced at around £34, depending on where you shop. The 2GB memory version is on sale for around £44, while the top-end, 4GB memory version will set you back in the region of £54. Together with the cost of the Pi itself, you will…

FASTER AND CONNECTED There’s a lot to like about the Pi 500: with a modified Raspberry Pi 5 under the hood, up to 8GB of on-board memory, a faster quad-core CPU, support for dual 4K displays via a pair of micro-HDMI ports, and more. Let’s take a look at the Pi 500, and see what it’s got under-the-hood. TECH SPECS A compact and powerful computer integrated into a high-quality keyboard, offering the ultimate PC experience. The Raspberry Pi 500 boasts the same quad core 64-bit Arm processor and RP1 I/O controller as its predecessor, the Raspberry Pi 5. Equipped with a one-piece aluminium heatsink, it ensures optimal thermal performance, allowing for sustained and smooth operation even under demanding loads. Additionally, it delivers stunning dual 4K display output. ESSENTIAL ADD-ON The…

The Pi Pico 2 may be small, but it packs a decent punch. With it you can expand your electronics projects, and incorporate a whole new level of functionality that you weren’t able to before with the traditional Raspberry Pi units. PICO 2 SPECIFICATIONS 21mm × 51mm form factor RP2350A microcontroller chip designed by Raspberry Pi in the UK Dual-core Arm Cortex-M0+ processor, flexible clock running up to 133 MHz 520KB on-chip SRAM 4MB on-board QSPI Flash 30 multifunction GPIO pins, including 3 analogue inputs 2 × UART, 2 × SPI controllers, 2 × I2C controllers, 24 × PWM channels 1 × USB 1.1 controller and PHY, with host and device support 8 × Programmable I/O (PIO) state machines for custom peripheral support Supported input power 1.8–5.5V DC Operating temperature-20°C…

THE POWER OF PI With many different versions across four generations of models, the Raspberry Pi is certainly a busy little board. But while each Pi offers something slightly different, for the newcomer it’s a confusing medley of hardware specifications and model numbers. Which, Raspberry Pi hardware, then is going to be best for you? Naturally, that questions depends greatly on what it is you want to do with your Raspberry Pi. If you have a particular project in mind, such as a home media centre server, then you’d probably opt for the more powerful and hardware-capable model of Raspberry Pi. If you want to setup a wireless security camera project, using the Raspberry Pi as the core hardware, then perhaps the Pi Zero W would be a better fit.…

You should install NOOBS (New Out Of Box Software) on your SD Card before you go any further. This feature looks at how to format an SD Card and copy the software using an Apple Mac computer. GETTING TO KNOW NOOBS The easiest way to get up and running is to use NOOBS, a software program created by the Raspberry Pi Foundation. You can buy a NOOBS SD Card from Raspberry Pi but it’s easy to make your own with an old unused SD Card (8GB recommended). STEP 1 We’re going to use a utility called SD Card Formatter 5 to erase the SD Card with correct formatting. You can download this app from https://www.sdcard.org/downloads/formatter_4/. Click Download SD Formatter for Mac and Accept. Click the SDFormatter.pkg file in your Downloads…

STEP 1 One of the most important command line instructions to know is sudo. This command stands for “substitute user do”, sometimes incorrectly called “super user do” and allows you to run a command as another user. Typically this is the root user account, which has more access privileges than your user account. STEP 2 When you start a command with sudo it is run as the root user and is often used when changing files outside of your user account, such as installing new programs. When you enter sudo you will be asked to enter your user password. Enter: sudo-v and press enter. STEP 3 The first time you enter sudo you’ll be given a warning message. Commands to make, edit and delete files prefaced with sudo can be…

ADVANCED PACKAGING TOOL Add / Remove Software is great for finding and installing software but most of the time you manage apps on a Raspberry Pi using a program called APT (Advanced Packaging Tool) using the apt command. STEP 1 To manage the apps on your Raspberry Pi you’ll need to use a tool included with Raspberry Pi OS called APT (Advanced Packaging Tool). APT is a command line tool so you need to either start your Raspberry Pi in the command line or click on the Terminal icon. STEP 2 The command used to control packages in Raspberry Pi OS is apt Type apt into the terminal and press Return to get a description of what the app does. The instructions tell us that the “most frequently used commands…

STEP 1 As you start to move files around you will find navigating between the same folders tiresome. It is possible to open locations in File Manager as tabs, so you can quickly jump back and forth. Click the Create new tab for this folder icon, just below the File menu, and the current folder opens as a tab. Click the tabs to jump between locations. STEP 2 To view the properties of a file right-click and choose Properties. Here you can view information about the File Type and the Open With application. More importantly, if you click Permissions you can view the permissions associated with that file. The concept of file permissions, especially the ‘Execute’ setting, becomes increasingly important as you become more advanced in using your Raspberry Pi.…

STARTING PYTHON For those using the Pi 4 and new Raspberry Pi OS, drop into a Terminal and enter: sudo apt-get install idle3. Older versions of Raspberry Pi OS already have the official Python IDLE pre-installed. STEP 1 With the Raspberry Pi OS desktop loaded, click on the Menu button followed by Programming > Python 3 (IDLE). This will open the Python 3 Shell. Windows and Mac users can find the Python 3 IDLE Shell from within the Windows Start button menu and via Finder. STEP 2 The Shell is where you can enter code and see the responses and output of code you’ve programmed into Python. This is a kind of sandbox, where you’re able to try out some simple code and processes. STEP 3 For example, in the Shell…

Although we’re working from the GUI IDLE throughout this book, it’s worth taking a look at Python’s command line handling. We already know there’s a command line version of Python but it’s also used to execute code. COMMAND THE CODE Using the code we created in the previous tutorial, the one we named hello.py, let’s see how you can run code that was made in the GUI at the command line level. STEP 1 Python, in Linux, comes with two possible ways of executing code via the command line. One of the ways is with Python 2, whilst the other uses the Python 3 libraries and so on. First though, drop into the command line or Terminal on your operating system. STEP 2 Just as before, we’re using a Raspberry…

VARIOUS VARIABLES You’ll be working with the Python 3 IDLE Shell in this tutorial. If you haven’t already, open Python 3 or close down the previous IDLE Shell to clear up any old code. STEP 1 In some programming languages you’re required to use a dollar sign to denote a string, which is a variable made up of multiple characters, such as a name of a person. In Python this isn’t necessary. For example, in the Shell enter: name=”David Hayward” (or use your own name, unless you’re also called David Hayward). STEP 2 You can check the type of variable in use by issuing the type () command, placing the name of the variable inside the brackets. In our example, this would be: type (name). Add a new string variable:…

MASTERING MODULES Think of modules as an extension that’s imported into your Python code to enhance and extend its capabilities. There are countless modules available and as we’ve seen, you can even make your own. STEP 1 Although good, the built-in functions within Python are limited. The use of modules, however, allows us to make more sophisticated programs. As you are aware, modules are Python scripts that are imported, such as import math. STEP 2 Some modules, especially on the Raspberry Pi, are included by default, the Math module being a prime example. Sadly, other modules aren’t always available. A good example on non-Pi platforms is the Pygame module, which contains many functions to help create games. Try: import pygame. STEP 3 The result is an error in the IDLE…

STEP 1 Enter: ls - lah/ to view all of the files and directories, including the hidden items, in the root directory of your hard drive. Here you will see all the items that make up your Raspberry Pi OS OS (which is a version of Linux). It’s worth taking the time to know some of them. STEP 2 Bin is a directory that stores binaries. This is the Linux way of saying programs or applications. Sbin is for system binaries, which are the programs that make up your system. Dev contains references to your devices: hard drive, keyboard, mouse and so on. Etc contains your system configuration files. STEP 3 Entering: ls/home displays the contents of your home directory, which contains pi; the directory that you start in. So, entering:…

USING THE MOVE COMMAND In Linux, renaming a file is simply moving it from one name to another and copying a file is moving it without deleting the original. Don’t panic, it’s quite easy to master. STEP 1 Before we can move anything around, we need to have a few test items in our home directory. Enter: touch testfile and mkdir testdir to create a test file and test directory in your home directory. Enter: ls to check that they are both present. STEP 2 Files and directories are moved using the mv command. This is different to the commands we’ve looked at so far because it has two arguments (remember Linux command line is command, option, argument). The first argument is the source (the file or directory to be…

THE JOY OF TEXT You will come across a lot of text files in Linux and to be able to edit or create a text file, you need a good text editor. Linux has many but here are some in action on the Raspberry Pi. STEP 1 The first text editor for the Raspberry Pi is the default desktop environment app: Leafpad. To use, you can either double-click an existing text file or click the Raspberry Pi menu icon (in the top left of the desktop) and from the Accessories menu, choose Text Editor. STEP 2 From the Terminal there are even more options, although using the correct command, you can launch any of the desktop apps via the Terminal. One of the simplest, and a classic text editor that’s…

OWNER AND PRIVILEGE Each user account in Linux is an owner of a section of the filesystem: their Home area. Within this area, they do what they like (within reason), as they have owner privileges. Elsewhere though, they usually just have read-only privileges. STEP 1 If you followed the previous tutorial you should now have two accounts on your Raspberry Pi. One called “pi” and the other with a name (Lucy in our case). An essential aspect of Linux is the idea of file and directory ownership; who owns, and has access, to what. You need a test file so enter: touch testfile. STEP 2 Now enter: ls –l and let’s have a good look at the default permissions file. Our testfile.txt files starts with the text “-rw-r--r—“. Start with the…

IN, OUT, LINUX ALL ABOUT Everything on a computer is about input and output. You input things into the computer (press keys, move the mouse) and it makes calculations and outputs content (changes the display, makes a noise, for example). STEP 1 When you enter commands into Linux (in the command line), you are using standard input and output. This is so obvious that most people don’t even think about it. You enter commands using the keyboard (that’s input) and it responds to the screen (output). This is the regular way of doing it, which is why it’s “standard input and output” (often called “stdin” and “stdout” for short). STEP 2 As far as the computer is concerned, input and output can be to and from a whole range of…

free The ‘free’ command displays the total amount of free and used physical and swap memory in the system. For example, free -m gives the information using megabytes. df The ‘df’ command displays filesystem disk space usage for all partitions. The command df-h is probably the most useful (the -h means human-readable). top The ‘top’ program provides a dynamic realtime view of a running system. It can display system summary information, as well as a list of processes. uname The ‘uname’ command with the -a option prints all system information, including machine name, kernel name, version and a few other details. ps The ‘ps’ command allows you to view all the processes running on the machine. Every operating system’s version of ps is slightly different but all do the same…

TO BOLDLY GO… Indeed, the ISS is something most of us consider as a worthy example of what can happen when we work together. NASA, among other agencies, uses a wealth of Python code onboard the ISS to help automate routines, alongside its function as an in-between link to translate code from one language to another, and then into a human-readable format. If you’re considering a career in space, then learning Python is a must have skill. While we’re not able to fill you in on all the details regarding the code the ISS utilises, we can look at a fun Python script that will track the ISS, display the number of astronauts on board, and update the station’s current latitude and longitude every five seconds, while also displaying your…

ASCII ANIMATION Let’s assume you wanted to create an animated ASCII Happy Birthday Python script, with the words Happy and Birthday alternating in appearance. Here’s how it’s done. STEP 1 First we need to create some ASCII-like text, head over to http://patorjk.com/software/taag. This is an online Text to ASCII generator, created by Patrick Gillespie. Start by entering Happy into the text box, the result will be displayed in the main window. You can change the font with the drop-down menu to the side of the text box; we’ve opted for Big. STEP 2 Now, on your computer create a folder in your Python code directory (call it Test, for now) and open either Leafpad for the Raspberry Pi or, if you’re using Windows 10, then Notepad. Click on the Select…

IT’S RAINING PI, HALLELUJAH! Weather stations have been available to the projectminded public since long before the Raspberry Pi entered the scene, but thanks to the Pi’s unique specifications, a new generation of weather station has emerged; and they’re really quite remarkable. As with a lot of Raspberry Pi projects, the market has become flooded with various hardware, kits, and HATs that will enable you to set up a simple, or complex, weather station. The more experienced weather station and Raspberry Pi user will probably lean toward buying in the components individually, as opposed to an entire kit, but for the rest of us the kit-form versions are an excellent start to a project that can quickly grow over time. WHY? With our smart devices connected to everything around us…

PI 5 SPEC SHEET 2.4GHz quad-core 64-bit Arm Cortex-A76 CPU VideoCore VII GPU, supporting OpenGL ES 3.1, Vulkan 1.2 Dual 4Kp60 HDMI® display output 4Kp60 HEVC decoder Dual-band 802.11ac Wi-Fi® Bluetooth 5.0 / Bluetooth Low Energy (BLE) High-speed microSD card interface with SDR104 support 2× USB 3.0 ports, supporting simultaneous 5Gbps operation 2× USB 2.0 ports Gigabit Ethernet, with PoE+ support 2× 4-lane MIPI camera/display transceivers PCIe 2.0 x1 interface for fast peripherals…

Inside the Pi 400 is a modified Raspberry Pi 4. It’s longer, spanning the width of the keyboard, with a large heatsink to dissipate enough heat for the overclocked processor. The Pi 4’s communication ports are spaced along the back of the Pi 400 keyboard, minus a second USB 2.0 port and a 3.5mm audio jack. TECH SPECS The Pi 400 has a slight advantage over the Raspberry Pi 4 in terms of its processing power, but it loses out in the overall memory department. However, the specs are an impressive Broadcom BCM2711 quad-core Cortex-A72 (ARM v8) 64-bit SoC, overclocked to 1.8GHz – and tests have shown that the Pi 400 can be further overclocked to a stable 2.2GHz. And there’s 4GB of LPDDR4-3200 memory available too. Not bad for…

The Pico is something entirely different from the Raspberry Pi Foundation’s usual releases. Whereas the Raspberry Pi, now on version 4, is a small computer, and even the Compute Module and the Pi 400 are still just computers, the Pico is actually a microcontroller. A microcontroller is a processing unit that’s designed to work with programmable peripherals, and has input and output modules alongside a small amount of memory and storage capabilities. The processors are often scaled down, compared to the processor on a Raspberry Pi, or even inside your desktop computer, but powerful enough to complete basic tasks. Examples of a microcontroller in action can be found inside a washing machine, or traffic lights. A washing machine has no need for a quad-core processor, 8GB of memory, and the…

An SBC, or Single-Board Computer, is a complete computer system that’s built on a single piece of circuit board; consisting of memory, storage and input and output ports. The Raspberry Pi is a prime example of a modern SBC, and the one that has easily become the most popular available in an increasingly crowded marketplace. However, there are a number of other SBCs available that vary in size, capacity, performance, price and expandability. Some of them are x86-based, which means they’re basically very small PCs on which you can install Windows 10; others utilise different makes of processor or microprocessors and offer a varied number of operating systems that will work on them, such as Android or Linux. While the Raspberry Pi is the SBC that offers some of the…

ASK AROUND The kit list required to set up a Raspberry Pi is pretty basic: keyboard, mouse, HDMI monitor, SD Card and an optional case. Many of these items you’ll already have, but don’t rush out and buy those you don’t. Ask around to see if anybody you know has spares. STEP 1 The most important thing you need is an SD Card. These are the storage cards commonly found in digital cameras. All modern Raspberry Pi boards, including the Raspberry Pi 3 and Pi Zero, use Micro SD cards but the older boards may use a larger SD Card. STEP 2 The SD Card plugs into the SD Card socket. On the Raspberry Pi 4, 3, and Pi Zero, you push the card in and pull it out. On…

SETTING UP WITH NOOBS NOOBS (New Out Of Box Software) is a program used to make setting up a Raspberry Pi simple. You can buy SD Cards with NOOBS preinstalled, but here we’ll look at how to format your SD Card and install NOOBS using a Windows computer. STEP 1 We’re going to use a utility called SD Card Formatter to erase the SD Card with correct formatting. You can download this app from https://www.sdcard.org/downloads/formatter/eula_windows/index.html. Click the Accept button to start the download of the latest version of the software. Extract the software, and double-click the executable to install and run the app. STEP 2 We’re going to use an 8GB SD Card to install the operating system on our Raspberry Pi. The card needs to be formatted, which will…

PIXEL PIXEL stands for “Pi Improved Xwindow Environment, Lightweight”. It’s a lightning fast and energy saving desktop that looks good too. It contains almost everything you’ll ever need to work with the Pi. THE DESKTOP The PIXEL interface is a module that’s installed on top of the core OS. It has seen some improvements over the years, and with the release of the Pi 4 and Raspberry Pi OS Buster, it now looks like this. THE PROGRAMS The programs that come pre-installed with Raspberry Pi OS are easily located by clicking on the Raspberry Pi logo in the upper left corner of the desktop. Once there, you can select from the sub-menu categories, followed by the program name. PRODUCTIVITY You’ll notice that within the Main menu, there’s a category named…

CUSTOM TERMINAL The Terminal gives you access to the command line, where the real power of the Linux OS lies. Getting used to the Terminal is key to mastering the Pi and your projects. STEP 1 Start Terminal by clicking the Terminal icon in the Application Launch Bar. You can also start Terminal by pressing Control-Alt-T or choosing Menu > Accessories > Terminal. Terminal emulates the old style video terminals from before desktop interfaces; so by default it displays bright (mostly green) on a black background. STEP 2 The first thing most people overlook is the ability to run multiple terminals at once in different tabs. Choose File > New Tab (Shift-Control-T) to create a new tab. Navigating multiple directories simultaneously can be a challenge in Terminal and tabs makes…

GET TO KNOW GIMP Your Raspberry Pi can display images with its built-in Image View app but for any image editing you’ll need GIMP (GNU Image Manipulation Program). GIMP is a powerful software package for photo editing and is a great tool to install on your Raspberry Pi. STEP 1 Open terminal and enter: sudo apt install gimp to download and install the GIMP package. An alert will appear saying: “after this operation, 117 MB of additional disk space will be used. Do you want to continue [Y/n]?” Enter: y and press Return. GIMP will now be installed in Raspberry Pi OS. GIMP is a lot larger than most programs you’ll install, so the installation takes STEP 2 When the installation has completed you will find GIMP under Menu >…

Essentially, you’ve already written your first piece of code with the ‘print(“Hello everyone!”)’ function from the previous tutorial. However, let’s expand that and look at entering your code and playing around with some other Python examples. PLAYING WITH PYTHON With most languages, computer or human, it’s all about remembering and applying the right words to the right situation. You’re not born knowing these words, so you need to learn them. STEP 1 If you’ve closed Python 3 IDLE, reopen it in whichever operating system version you prefer. In the Shell, enter the familiar following:  print(“Hello”) STEP 2 Just as predicted, the word Hello appears in the Shell as blue text, indicating output from a string. It’s fairly straightforward and doesn’t require too much explanation. Now try: print(“2+2”) STEP 3 You…

IT’S ALL MATHS, MAN You can get some really impressive results with the mathematical powers of Python; as with most, if not all, programming languages, maths is the driving force behind the code. STEP 1 Open up the GUI version of Python 3, as mentioned you can use either the Shell or the Editor. For the time being, you’re going to use the Shell just to warm our maths muscle, which we believe is a small gland located at the back of the brain (or not). STEP 2 In the Shell enter the following: You can see that Python can handle some quite large numbers. STEP 3 You can use all the usual mathematical operations: divide, multiply, brackets and so on. Practise with a few, for example: STEP 4 You’ve…

DEBUGGING Errors in code are called bugs and are perfectly normal. They can often be easily rectified with a little patience. The important thing is to keep looking, experimenting and testing. Eventually your code will be bug free. STEP 1 Code isn’t as fluid as the written word, no matter how good the programming language is. Python is certainly easier than most languages but even it is prone to some annoying bugs. The most common are typos by the user and whilst easy to find in simple dozen-line code, imagine having to debug multi-thousand line code. STEP 2 The most common of errors is the typo, as we’ve mentioned. The typos are often at the command level: mistyping the print command for example. However, they also occur when you have…

GETTING AROUND To drop into the Terminal, click on the fourth icon from the left along the top of the Raspberry Pi desktop, the one with a right-facing arrow and an underscore. This is the shell, or Terminal. STEP 1 First, you’re going to look at directories and the directory path. A directory is the same thing as a folder, however in Linux it’s always called a directory. These are placed inside each other using a “/” character. So when you see/home/pi it means the pi directory is inside the home directory. Enter: clear and press return to clean the screen. Now enter: pwd. This stands for Print Working Directory and displays/home/pi. STEP 2 When you log in to your Raspberry Pi, you don’t start at the base of the…

CREATING FILES Once you learn to recognise the files and directories that make up Raspberry Pi OS OS, it’s time to discover how to make your own. Knowing how to make, edit and delete files and directories is essential if you want to make your own projects. STEP 1 We’re going to create a file using a command called Touch. Touch is an interesting command that reaches out to a file, or directory, and updates it (this changes the system time as if you’d just opened the file). You can see Touch in access using “ls –l” and checking the time next to a directory (such as Scratch). STEP 2 Now enter: touch Scratch and ls – l again and notice that the time has changed. It now matches the current…

STEP 1 Let’s start by making a new test file called “names”. Enter: touch testfile and then ls to make sure the testfile is present. We’re going to turn this into a file that contains the names of some people. So let’s call it something more appropriate, like “names”. STEP 2 Enter: mv testfile names and ls. Now we can see the new “names” file in our directory. The mv command can also be used to rename directories. We should still have our newparent directory in our home directory. Enter: mv newparent people to rename the newparent directory. Enter: ls to view it. STEP 3 You can rename directories inside other directories using paths. Let’s rename the testdir directory, which is now inside the people directory. Enter: mv names/testdir names/friends. Now…

WHAT IS A USER? An important part of using Linux is the concept of users and understanding which user you are and which group you belong to. Like all modern computers, you can have multiple user accounts with each having different levels of access. STEP 1 The first thing you need to do is get a concept of which user you are. Enter: whoami into the command line and press return. It should say “pi” (unless you set up your account name differently during setup). The “whoami” command might seem a bit simplistic, but it comes in very handy sometimes. STEP 2 When you are working in Linux, from time to time a ‘Permission denied’ error will occur, typically when you try to create, edit or execute (run) a file…

LOTS OF LINUX Linux is a huge and versatile command line language and there are hundreds of commands you can learn and use. Here are a few that can help you get more from your Raspberry Pi. STEP 1 The Raspberry Pi is a great little computer, so let’s start by getting some information. Enter: cat/proc/cpuinfo to view some details on your Raspberry Pi processors. If you have a Raspberry Pi 3 you will see four processors, along with the model name and other info. STEP 2 Remember that cat is used to list the contents of a text file, which is what cpuinfo is. There are other text files with system info available. Try “cat/proc/meminfo” to get information about your memory, “cat/proc/partitions” for information about your SD card, and…

STEP 1 As you start to get more advanced in Linux, you begin to create more powerful commands, and one way you do this is by using the pipe character (“|”). Take some time to find this character if you haven’t already: it usually sits above or to the left of the Return key on most keyboards. STEP 2 We’ve used the pipe a few times in the book (“ps aux | less”), but you might not have understood what’s actually happening. Enter: cat bands.txt | wc. The output from the cat command (the text inside the document) isn’t displayed on the screen, instead it is piped into the wc (word count) function. This then tells us how many lines, words and characters are in the document. STEP 3 You…

TV HAT In this tutorial, we’re using the Raspberry Pi TV HAT as sold by The Pi Hut (https://thepihut.com/products/raspberry-pi-tv-hat?variant=13539182673982). It’s a Sony CXD2880 TV Tuner supporting DVB-T and 2nd-gen DVB-T2 standards. STEP 1 The Raspberry Pi TV HAT is compatible with the Pi Zero, Pi 3 A+ and B+ models. The kit comes with everything you need to connect the HAT to your RPi, including spacers, screws and the 40-pin header. Begin by opening the box and spreading the contents out on a clear area. STEP 2 Start by connecting the 40-pin header to the 40-pin GPIO on top of your Raspberry Pi. Now take the spacers and screws and fit them to the corresponding holes in the corners of the main Raspberry Pi and the TV HAT; use three…

TROUBLESHOOTING YOUR RPI The Raspberry Pi is a surprisingly stable bit of kit, but there is always the chance of encountering problems. If you’re really stuck there are apps available which can help diagnose problems on the RPi. RED POWER LED IS BLINKING A blinking red power LED indicates problems with the power supply. On model A and B, it is hard-wired to the 3.3V power supply rail. If it is blinking, it means the 5V power supply is dropping out. Use a different power supply. On the model B+ and also the A+, the circuit has been improved to give a much more reliable warning of poor power quality. The red power LED is wired to an APX803 supervisor which kicks in when the 5V power supply drops below…