Author: Bryan Cockfield

1757 Articles

A High Resolution ADC From Scratch

October 4, 2025 by 6 Comments

It’s a well-known conundrum that while most computers these days are digital in nature, almost nothing in nature is. Most things we encounter in the real world, whether it’s temperature, time, sound, pressure, or any other measurable phenomenon comes to us in analog form. To convert these signals to something understandable by a digital converter we need an analog-to-digital converter or ADC, and [Igor] has built a unique one from scratch called a delta sigma converter.

What separates delta sigma converters apart is their high sampling rate combined with a clever way of averaging the measurements to get a very precise final value. In [Igor]’s version this average is provided by an op-amp that integrates the input signal and a feedback signal, allowing for an extremely precise digital value to be outputted at the end of the conversion process. [Igor] has built this one from scratch as well, and is using it to interface a magnetic rotary encoder to control digital audio playback.

Although he has this set up with specific hardware, he has enough detail in his video (including timing diagrams and explanations of all of the theory behind these circuits) for anyone else to build one of these for other means, and it should be easily adaptable for plenty of uses. There are plenty of different ADC topologies too, and we saw many different ones a few years ago during our op-amp challenge.

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The Internet We Didn’t Get

October 2, 2025 by 13 Comments

Collective human consciousness is full of imagined or mythical dream-like utopias, hidden away behind mountains, across or under oceans, hidden in mist, or deep in the jungle. From Atlantis, Avalon, El Dorado, and Shangri-La, we have not stopped imagining these secret, fantastical places. One of these, Xanadu, is actually a real place but has been embellished over the years into a place of legend and myth, and thus became the namesake of an Internet we never got to see like all of those other mystical, hidden places.

The Xanadu project got its start in the 1960s at around the same time the mouse and what we might recognize as a modern computer user interface were created. At its core was hypertext with the ability to link not just other pages but references and files together into one network. It also had version control, rights management, bi-directional links, and a number of additional features that would be revolutionary even today. Another core feature was transclusion, a method for making sure that original authors were compensated when their work was linked. However, Xanadu was hampered by a number of issues including lack of funding, infighting among the project’s contributors, and the development of an almost cult-like devotion to the vision, not unlike some of today’s hype around generative AI. Surprisingly, despite these faults, the project received significant funding from Autodesk, but even with this support the project ultimately failed.

Instead of this robust, bi-directional web imagined as early as the 1960s, the Internet we know of today is the much simpler World Wide Web which has many features of Xanadu we recognize. Not only is it less complex to implement, it famously received institutional backing from CERN immediately rather than stagnating for decades. The article linked above contains a tremendous amount of detail around this story that’s worth checking out. For all its faults and lack of success, though, Xanadu is a interesting image of what the future of the past could have been like if just a few things had shaken out differently, and it will instead remain a mythical place like so many others.

Improved 3D Printer Cannibalizes Two Older Printers

September 30, 2025 by 12 Comments

In the late 2010s, the Ender 3 printers were arguably the most popular line of 3D printers worldwide, and for good reason. They combined simplicity and reliability in a package that was much less expensive than competitors, giving a much wider range of people access to their first printers. Of course there are much better printers on the market today, leaving many of these printers sitting unused. [Irbis3D] had an idea that with so many of these obsolete, inexpensive printers on the secondhand market, he could build something better with their parts.

The printer he eventually pieces together takes parts from two donor Ender printers and creates a printer with a CoreXY design instead of the bedslinger (Cartesian) design of the originals. CoreXY has an advantage over other printer topologies in that the print head moves in X and Y directions, allowing for much faster print times at the expense of increased complexity. There are some challenges to the design that [Irbis3D] had to contend with, such as heating problems with the extruder head that needed some modifications, as well as a resonance problem common with many printer designs which can generally be solved by replacing parts one-by-one until satisfactory prints are achieved.

Of course, not all of the parts for the new printer come from the old Ender printers. The longer belts driving the print head needed to be ordered, as well as a few other miscellaneous bits. But almost everything else is taken from these printers, which can be found fairly cheaply on the secondhand market nowadays. In theory it’s possible to build this version for much less cost than an equivalent printer as a result. If you’re looking for something even more complicated to build, we’d recommend this delta printer with a built-in tool changer.

Thanks to [BusterCasey] for the tip!

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InfinityTerminal Brings Infinite Horizontal Scrolling

September 29, 2025 by 9 Comments

The creator of infinite vertical scrolling in social media, [Aza Raskin], infamously regrets his creation that has helped to waste a tremendous amount of human attention and time on the Internet. But that’s vertical scrolling. [bujna94] has created infinityTerminal, a program with infinite scrolling, but in the horizontal direction instead. This tool has had the opposite effect to go along with its opposite orientation: increased productivity and improved workflow.

The impetus for infinityTerminal is [bujna94]’s need for many simultaneous SSH sessions, and the fact that no other terminal program can support an indefinite number of visible terminal windows. This application starts with four terminal windows in a 2×2 grid, and allows the user to open more terminals, two at a time, to form a 2xN grid. As many terminals as needed will open in pairs in the horizontal direction with smooth, trackpad-compatible scrolling and automatic color-coded backgrounds for servers accessed by SSH.

For anyone with a similar dislike of tabs like [bujna94], this might be worth trying out. It’s built with Electron, xterm.js, and node-pty.

There are a few more details about the project on a Reddit post. [Bujna94] also made it completely open source and freely available with the files on a GitHub page, and welcomes anyone to try out his creation that wants to. For more terminal magic, we’d also recommend checking out Notcurses, a terminal application capable enough to output SNES-level detail natively.

Bringing Bluetooth To The Zune

September 27, 2025 by 10 Comments

The Zune might have joined the portable media player game too late to ever really be competition for the iPod, but that doesn’t mean it didn’t pick up some devoted fans along the way. Some of them are still breathing new life into the device, such as [The Director of Legal Evil Emeritus] at the Louisville Hackerspace, with this project that gives it Bluetooth capability.

As far as media players go, there’s still some solid reasons to rock a Zune. Compared to other devices of the era, it offers a better DAC, an FM tuner, and no iTunes reliance. The goal of this project was to bring a bit of modern functionality without having to do any modification of the Zune itself. As the player supported docks with IR remotes, this build involves using an ESP32 to listen to the Bluetooth signal coming from the speakers, interpret any button presses, and forward them along to the Zune’s dock.

There is a dedicated scene for these old music players, but this build is unique for not needing to crack open the case and splice in a Bluetooth module. Even then, those typically don’t have the ability to interact with things like this speaker with its integrated control buttons.

We don’t often seen Zune hacks come our way — the last time Microsoft’s player graced these pages was in 2010, when the Open Zune Development Kit was released.

Thanks to [JAC_101] for the tip!

UNIX For A Legacy TI

September 26, 2025 by 14 Comments

Although now mostly known as a company who cornered the market on graphing calculators while only updating them once a decade or so, there was a time when Texas Instruments was a major force in the computing world. In the late 70s and early 80s they released a line of computers called the TI-99 to compete (unsuccessfully) with various offerings from Commodore, and these machines were fairly robust for the time. They did have limited memory but offered a 16-bit CPU and plenty of peripherals, and now there’s even a UNIX-like OS that they can run.

This version of UNIX is called UNIX99 and is the brainchild of AtariAge forum member [mrvan] who originally wasn’t looking to develop a full operating system for this computer but rather a set of standard C libraries to help with other projects. Apparently the step from that to a UNIX-flavored OS wasn’t too big so this project was born. While the operating system doesn’t have a UNIX certification, it has most of the tools any of us would recognize on similar machines. The OS has support for most of the TI-99 hardware, file management, a basic user account system, and a command shell through which scripts can be written and executed.

That being said, the limitations of the hardware do come through in the operating system. There’s no multitasking, for example, and the small amount of memory is a major hurdle as well. But that’s what makes this project all the more impressive, and [mrvan] isn’t stopping here. He’s working on a few other improvements to this platform, and we look forward to seeing future releases. UNIX itself is extremely influential in the computing world, and has been used a the model for other homebrew UNIX-like operating systems on similar platforms of this era such as the Z80.

Thanks to [Stephen] for the tip!

Photo courtesy of Rama & Musée Bolo via Wikimedia Commons

Robot Bartender Is The Life Of The Party

September 26, 2025 by 9 Comments

As the old saying goes, when the only tool you have is a 6 DOF industrial robotic arm, every problem looks like an opportunity to make it serve up adult beverages. [benkokes] found himself in this familiar predicament and did what any of us would do, but his process wasn’t without a few party fouls as well as a few head-scratchers.

One of the common problems that people who suddenly find themselves with an old industrial robot have is that there’s usually no documentation or instructions. This was true here with the added hiccup of the robot’s UI being set to Chinese. Luckily no one had changed the root password, and eventually he was able to get the robot up and working.

Getting it to make drinks was a different matter altogether. [benkokes] needed a custom tool to hold the cup as well as shake it, and 3D printed a claw-style end effector with a lid. Out of his multi-colored pack of party cups, however, the orange cups were different enough in dimension to cause problems for the shaking lid which was discovered when the robot spilled a drink all over the table.

Eventually, though, the robot was successfully serving drinks at a party. One of [benkokes]’s friends happened to be a puppet maker and was able to outfit it with a tailored tuxedo for the party as well, and he also programmed it to dance in between serving drinks, completing the AI revolution we have all been hoping for. Perhaps unsurprisingly, this is a common project for people who suddenly come to posses a large general-purpose industrial robot, while others build robots specifically for this task alone.

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