2026-03-26 10:00:47
Many people base huge swaths of their lives on foundational philosophical texts, yet few have read them in their entirety. The one that springs to the forefront of many of our minds is The Art of Computer Programming by Donald Knuth. Full of many clever and outright revolutionary algorithms and new ways of thinking about how computers work, [Attoparsec] has been attempting to read this tome from cover to cover, and has found some interesting tidbits. One of those is the various algorithms around Gray Codes, and he built this device as a visual aid.
Gray Codes, otherwise known as reflected binary, is a way of ordering an arbitrarily large set of binary values so that only one bit changes between any two of them. The most common place these are utilized is in things like rotary encoders, where it provides better assurance that the position of a shaft is in a known location. To demonstrate this in a more visual way [Attoparsec] hooked up an industrial signal light, normally used for communicating the status of machinery in a factory, and then programmed it to display the various codes. A standard binary counter is used as a reference, and it can also display standard Gray Code as well as a number of other algorithms used for solving similar problems.
[Attoparsec] built this as an interactive display for the Open Sauce festival in San Francisco. To that end it needed to be fairly rugged, so he built it out of old industrial equipment, which is also a fitting theme for the light itself. There’s also a speed controller and an emergency stop button which also add to the motif. For a deeper dive on Gray Codes and their uses, take a look at this feature from a few years back.
2026-03-26 07:00:13
In the maker world, it’s the Arduino and ESP32 lines that get the lion’s share of attention. However, you can do fantastic things with PIC chips, too, if you put the dev time in—it’s just perhaps less likely another maker has done so before you. A great example is this VGA output project from [grecotron].
A PIC18F47K42 is perhaps not the first part you would reach for to pursue any sort of video-based project. However, with the right techniques, you can get the 8-bit microcontroller pumping out the pixels surprisingly well. [grecotron] was able to get the chip outputting to a VGA monitor at a resolution of 360 x 480 with up to 16 colors. It took some careful coding to ensure the chip could reliably meet the timing requirements for the standard and to get HSYNC, VSYNC, and the color signals all dancing in harmony. Aiding in this regard was that the chip was clocked with a 14.3182 MHz crystal to make it easy to divide down from all the internal timers as needed. Supporting hardware is light, too—primarily consisting of a VGA connector, a couple of multiplexers, and resistor ladder DACs for the color signals. Files are on Github for those interested in deeper detail on the work.
VGA output is possible to implement on all kinds of microcontrollers—and even a bunch of raw logic if you know what you’re doing. If you’re pursuing your own video output wizardry, be sure to let us know on the tipsline.
2026-03-26 04:00:07
Digital clock projects have been with us since the 1970s, when affordable LEDs and integrated circuits became available. In 2026 most of them use a microcontroller, but for the AliExpress fans there’s one that goes straight back to the ’70s with a pile of logic chips. You can make it on the supplied PCBs, but that wasn’t for [ALTco]. Instead, he made the circuit in free form, using six metres of brass wire.
The construction is anchored together by a set of busbars that carry sockets for a set of seven-segment and driver modules. The circuit is typical for the day, with a crystal oscillator and divider chain feeding the counters for the displays. There are a few clever tricks that older engineers might recognize in order to reduce the chip count. In this case that’s negated by an extra set of circuitry allowing the time to be set from a rotary encoder.
We’re impressed by the intricacy of the device, made bit by bit without a plan, it as some wires what thread their way between others. It’s a truly beautiful piece, and it reminds us of our circuit sculpture contest back in 2020.
2026-03-26 02:30:41
This week Jonathan chats with Milo Schwartz about Pangolin, the Open Source tunneling solution. Why do we need something other than Wireguard, and how does Pangolin fix IoT and IT problems? And most importantly, how do you run your own self-hosted Pangolin install? Watch to find out!
Did you know you can watch the live recording of the show right on our YouTube Channel? Have someone you’d like us to interview? Let us know, or have the guest contact us! Take a look at the schedule here.
Direct Download in DRM-free MP3.
If you’d rather read along, here’s the transcript for this week’s episode.
Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
2026-03-26 01:00:44
Digital Convergence Corporation is hardly a household name, and there’s a good reason for that. However, it raised about $185 million in investments around the year 2000 from companies such as Coca-Cola, Radio Shack, GE, E. W. Scripps, and the media giant Belo Corporation. So what did all these companies want, and why didn’t it catch on? If you are old enough, you might remember the :CueCat, but you probably thought it was Radio Shack’s disaster. They were simply investors.
The :CueCat was a barcode scanner that, usually, plugged into a PC’s keyboard port (in those days, that was normally a PS/2 port). A special cable, often called a wedge, was like a Y-cable, allowing you to use your keyboard and the scanner on the same port. The scanner looked like a cat, of course.
However, the :CueCat was not just a generic barcode scanner. It was made to only scan “cues” which were to appear in catalogs, newspapers, and other publications. The idea was that you’d see something in an ad or a catalog, rush to your computer to scan the barcode, and be transported to the retailer’s website to learn more and complete the purchase.
The software could also listen using your sound card for special audio codes that would play on radio or TV commercials and then automatically pop up the associated webpage. So, a piece of software that was reading your keyboard, listening to your room audio at all times, and could inject keystrokes into your computer. What could go wrong?
You might think this was some tiny startup that died with a whimper, but Radio Shack, Forbes, Wired, and several major newspapers were onboard. The :CueCat cost about $6.50 to produce, but most people never bought one. Radio Shack, Forbes, and Wired were giving them away.
The problem is, even free was too high a price for most people. To use the device, you had to register and complete a long survey full of invasive questions. Then the software showed you an ad bar. Digital Convergence had your demographic info, your surfing habits, and knew what you were scanning.
Even then, the scanner solved a non-problem. If you saw something in a Radio Shack catalog, for example, it was probably not so hard to go to their website and search for it by title or stock number. Especially if you were sitting in front of your computer. If you weren’t… well, then, the :CueCat didn’t help you in that case, anyway.
It is easy to look back on this and think, “What a bad idea?” But Digital Convergence and its investors were in a full-blown media blitz. The video below shows a contemporary demo of the technology.
If you still aren’t sold, look at how happy the woman in the Radio Shack commercial is that she didn’t have to manually search the web for her next phone purchase.
Problem solved, right? Want to buy that new ham radio? Scan the code, and you don’t have to type “Alinco” into a search box! Even the table of contents in the 2002 RadioShack catalog was festooned with barcodes.
The RadioShack catalog might have been an exception, though. A 2001 issue of Forbes magazine showed sparing use of the barcodes and no obvious ones linking to big advertisers. You would think the advertisers would have been a prime target, even if you had to make deals to get them onboard.
Naturally, hacks immediately appeared. Drives from [Pierre-Philippe Coupard] and [Michael Rothwell] allowed you to use the :CueCat without the invasive software or registration. You could even scan normal barcodes like UPC codes. Radio Shack and others wound up simply giving away $6.50 barcode scanners.
While people were already prickly about the amount of information gathered and the tracking, hackers found a report file on a public server that revealed personal info about 140,000 users — a huge number for the year 2000.
With hackers attacking both the hardware and the company’s website, Digital Convergence had to act. They changed their license, claiming that you didn’t own the scanner and forbidding reverse engineering. There were no real lawsuits, but there were threats and, as you might imagine, that just made things worse.
By 2001, there were a very few USB-native :CueCats distributed. But the bad publicity and the lack of usefulness took its toll. By mid-year, most of the 225 employees at Digital Convergence had been let go. Later in the year, the investors decided to stop using the tech entirely.
By 2005, you could buy the now-surplus devices for $0.30 each, as long as you agreed to take 500,000 or more of them. You can still find them on the used market if you look. Open source software is still around that can make them do useful things, but honestly, unless you’re hacking it into a custom hardware setup, your phone is a better barcode scanner.
You can still find some of the contemporary teardowns of the :CueCat online. There were, apparently, several revisions of the hardware, but at least one version had a cheap CPU, a serial EEPROM, an 8 KB static RAM, and a handful of small parts. For a free device, the insides looked pretty good.
Of course, now we have QR codes. But these are somewhat more private, work with the ubiquitous cell phone, and even then haven’t caught on in the way Digital Convergence had planned.
Was it a good idea? That’s debatable. But giant privacy grabs usually go poorly. Granted, in 2000, that might not have been as obvious as it is today. But it still doesn’t keep companies from finding it out all over again.
Featured image: The :CueCat. Photo by [Jerry Whiting]
2026-03-25 23:30:30
Tech has a problem, an e-waste problem. Google is a common offender when it comes to this, creating a product just to end support a couple of years later. Thankfully, there are some lasting capabilities left in their defunct Stadia controllers. After hearing about these capabilities, [Bringus Studios] managed to turn this future e-waste into something new: a Bluetooth adapter for game controllers.
To give some credit to Google, once they announced the Stadia program was winding down, they released an updated firmware that let you use the controller as a generic Bluetooth gamepad. But there was also a rather unusual feature added — if another controller is connected to it via USB, its output will be passed along over Bluetooth as if it was coming from the Stadia controller itself.
This would allow you to wirelessly connect an Xbox 360 or PlayStation 3 controller to your computer, for example. But while a neat trick, having the two controllers plugged into each other is a bit awkward. So [Bringus Studios] decided to take the Stadia controller apart and turn it into a dedicated Bluetooth interface.
Unfortunately, a fair amount of Dremel work was required to fully disassemble the device. Additional PCB modifications allowed for tricking the main board into default joystick positions and removing some button boards. Slap a 3D printed box around the Frankenstein’d hardware and you’ll be able to add Bluetooth capability to a wide array of USB controllers.
While the end result can’t be used with every single controller, it still gives a unique use case for a defunct product. If you have some spare time, maybe check out the e-waste graveyard, where you too can turn abandoned products into something new.
