Indholdsfortegnelse for Makerspace #2 i Linux Magazine Special Editions

Special projects deserve special components, which is why a display with unusual dimensions acts as the basis for my living room music system. However, the path to the final version was fraught with challenges. A web radio based on a Pi Zero (Figure 1) came to life in 2018 as a lightweight tinkering project with a keyboard, mini-speakers, and a small LCD screen [1]. Now, however, it has found a permanent place on my audio/visual (AV) receiver (Figure 2). Today, it is no longer controlled by a keypad, but by an infrared remote control. This solution works well, but it has one obvious drawback: The display is simply too small for couch potatoes. Therefore, a new version of the project has been in the pipeline for quite some time but…

Bela is a programmable audio platform with incredible performance, an integrated development environment, a large active community, and virtually no limits. But it’s also a slightly unusual project because you need some extra hardware to make it properly work. That hardware is a BeagleBone Black with an optional shield that adds multiple digital, analog, and audio inputs and outputs. This setup, when combined with the Linux-based software stack, promises a 0.5ms (half) delay between when a sound is triggered by the software to when the audio exits the hardware. For comparison, a Mac can manage a few milliseconds with the very best expensive hardware, desktop Linux with a realtime kernel adds a few more milliseconds to this, an Arduino is in the 10ms range, and a Raspberry Pi the 20ms…

Every computer user is familiar with the scenario. Your favorite piece of hardware tells you “End of Support – sorry, this device is no longer supported” (Figure 1) or “This device will no longer receive software updates,” followed by the laconic advice to “Please consider upgrading.” No software is supported forever. The continual task of coding updates and bug fixes takes time and energy, and after some predetermined support interval, the vendor just stops providing patches for old versions in order to focus on later systems. With Chrome OS and Chromebook computers, the task of providing support is even more complicated. The term Chromebook does not define a single hardware system. Instead, Google contracts with several different hardware vendors to produce Chromebooks, including Samsung, HP, Toshiba, Asus, Dell, and many…

The earth’s atmosphere is made up of 78 percent nitrogen, 21 percent oxygen, and 1 percent argon. Depending on the environment, up to 4 percent water vapor can also be present. Carbon dioxide (CO2) only accounts for a share of 0.04 percent. But this share, along with the sun’s rays and some trace elements from the soil, enables plants to grow. Humans and animals, on the other hand, generate energy using oxygen to convert food. In the process, they emit CO2, which typically accounts for 4 percent of the air humans breathe out. In addition, humans excrete aerosols that can transmit respiratory diseases such as influenza or COVID-19. For this reason, CO2 content is a useful indicator of indoor air quality. If the CO2 level exceeds a value of 1000…

Installing and properly configuring an emulator is a time-consuming task, and then your emulator typically runs in a window, which completely spoils the retro look. Of course, in most cases, you’ll be able to change settings in order to better recreate the historical look and feel, but getting it just perfect takes some time. For one specific combination, namely the C64 emulator VICE running on a Raspberry Pi, Carmelo Maiolino has gone through the effort of setting up Combian64 [1], a great Linux image that runs out of the box on old and recent Pi models. You just write the image file to an SD card, put that into your Pi’s SD card slot, and turn on the power – it’ll then take 28 seconds until you see the C64…

Without light, nothing can be seen in photography, but with just a little background light and light brushes, you can create interesting motifs. For long exposures, you need a camera with manual adjustment and a tripod. A flashlight or laser pointer is sufficient to paint simple patterns or lettering into an on-going exposure. If you like to experiment, you might want to work with LEDs to achieve particularly interesting light graphics. I was interested in a creative approach and in trying out what can be achieved with modern pixel elements and clever programming. The idea of a light stick for light painting was born. In this article, I use a Raspberry Pi Pico to build a Micro-Python programmable LED light stick. Table 1: Materials The control does not require much…

My daughter and I looked at trying to repurpose an old eReader. Our goal was to make a kitchen kiosk display that would show items of daily interest. For us, that included news, stocks, and weather data that we pulled from the Internet, along with some local data from Arduino, Home Assistant [1], and Raspberry Pi nodes (Figure 1). In this article, we look at how to install Linux on an eReader and look at eReader Python apps and kiosk-mode web browser pages. Getting Started For this project, we used a Kobo Mini eReader, so the procedure to load a new operating system will vary somewhat according to the eReader model and manufacturer you use. First, crack open the eReader. The operating system (OS) and data are stored on a…

Home automation projects can take advantage of a number of good software packages (e.g., Home Assistant and Node-RED) to manage and monitor sensors and controllable devices. If you are interested in looking at an industrial controls approach to your automation projects, then OpenPLC [1] is a good package to consider. A programmable logic controller (PLC) is a hardened industrial hardware device that manages I/O and logic according to the IEC 61131-3 standard [2]. The OpenPLC open source software runs on a Raspberry Pi, Linux, or Windows PC, and it offers users a great way to learn industrial control concepts, programming languages, and communications protocols. In this article, I introduce IEC 61131-3 programming by creating three small OpenPLC programs that use ladder logic, function blocks, and structured text programming languages. The…

The Commodore Amiga was more than a gaming platform; its graphical interface, Workbench, was way ahead of its time. The Amiga models [1] rank among the particularly popular home computers of the 1980s and 1990s. The A500, A1200, and several other Amigas had the motherboard and a floppy drive integrated into the keyboard case. More professional variants like the A3000 were built more like a PC and housed the mainboard, expansion cards, and drives in a desktop or tower case. According to Wikipedia [1], the Amiga 500 is the best-selling model, which is what prompted Retro Games Ltd. to launch a replica that was released in April 2022, dubbed the A500 Mini [2]. The manufacturer is already known for reissues of other Commodore computers, such as the C64 (in miniature…

Photographers often rely on tabletop photography to take product photos for advertising campaigns or illustrations for magazines. Even a digital camera or smartphone is up to this task, but you have good reasons to look into USB and web cameras, as well. Armed with a 4K USB camera, a focus distance of 3cm, an integrated zoom function, and a Raspberry Pi with USB 3.0 ports, tabletop photographers can embark on their mission. Raspberry Pi Cameras Currently, the Raspberry Pi Foundation officially supports the V2 camera module (also available in the NoIR variant) and the Pi High Quality (Pi HQ) camera. The V2 module was introduced as the successor to the V1 module in 2016. The predecessor was based on an OmniVision 5647 sensor with a resolution of 5 megapixels (Mpx).…

There are some fun and interesting projects that can be done by repurposing an old home router. If you don’t have an old router lying around, you can usually find one for about $5-$25. These routers are easy to reflash, so a new programmer doesn’t have to worry about messing things up too badly. In this article, we will look at three projects to get some extra life out of an older router. The first project uses the router’s USB port to connect to third-party devices. The second project collects microcontroller and internal data, and the final project displays the data on the router’s web page and on a Raspberry Pi. Selecting a Router and Firmware A number of open source firmware solutions can breathe new life into an old…

For home automation projects, a Raspberry Pi offers a simple, low-cost approach to managing and controlling a wide variety of devices. Typically these devices are either digitally wired 0-5V devices such as motion detectors, or wireless Ethernet devices such as smart plugs. It’s important to note that a Raspberry Pi can also control USB-powered devices, such as USB fans, lights, and low-end controllers. In this article, I look at how to monitor, control, and measure USB power in two Raspberry Pi projects. The first project uses Node-RED to create a web dashboard to monitor and control USB lights. The second project turns on USB cooling fans according to the Pi’s CPU temperature. Controlling USB Ports A number of techniques allow you to control USB ports, and I found that one…

Back in the 1980s, turning on a computer meant starting the built-in BASIC interpreter. The experience was instant: You just plugged in the power cord or flipped the power switch, and half a second later you could start typing in a program. You, too, can experience the joys of programming in BASIC (short for “Beginner’s All-purpose Symbolic Instruction Code,” but nobody ever spells that out). All you need is a machine that can run a BASIC interpreter. Your options include old home computers such as the Commodore C64 and the Sinclair ZX Spectrum, retro machines such as the FPGA-based Spectrum Next or the software-emulator-based TheC64, and emulator programs for your regular computer (which can be installed locally or run in the web browser). In this article, I’ll cover some BASIC…

If you own an Amiga, you can use the original ROM; otherwise, you have to get it some other way. One good option is to buy the Amiga Forever Plus Edition [7] for just under $30 (EUR30). Manufacturer Cloanto is the current rights holder of all Kickstart versions and sells them, among other things, as part of this package. After you confirm payment, you can download directly from the store page, which gives you either an MSI installer (for Windows) or a ZIP archive (Figure 3). Unpack the AmigaForever9Plus.zip archive after completing the download and access the ISO image afdvd.iso. On Linux you can mount the image with a variant of the command and find the Kickstart ROMs in the Amiga Files/Shared/rom/folder. You need two files for PiMiga: the encrypted…