A Discrete Logic Word Clock

March 12, 2021 by Chris Lott 26 Comments

Self-acclaimed computer nerd [Kevin Koster] was tired of designing new TTL-logic clocks before finishing his previous designs. So he finally buckled down and completed this unique word clock, which uses only a handful of TTL chips. We can’t disagree with his friends who complained that they can’t read [Kev]’s handwriting, so perhaps this diagram will make it clearer.

Besides being a nice logic-only project, this will give an example to younger folks how much effort went into things which are so simple to implement today. We don’t see a Karnaugh map on the project page for sorting out the logic diodes driving the minutes LEDs. If [Kev] did it on the fly, as the rat’s nest of diodes on the schematic would suggest, we’re not sure whether to scold him or be impressed (he does redraw that logic very neatly on a separate sheet).

No worries about high speed wiring on this project. The main oscillator derives time from the 50 Hz AC transformer power supply, and outputs a reference clock signal of 16.7 mHz (not MHz), or once per minute. This is divided down to 3.3 mHz for the 5-minutes counter and again to 277 uHz for the hour counter. If you live in a 60 Hz power mains country, you’d have to modify the oscillator section. Or you could contact [Kev] on his site, as he is considering making this available as a kit worldwide. If you like word clocks, we’ve covered quite a few of them before, including this crazy-complex rear-projection one.

A Different Kind Of 3D Printer: Desktop Holograms

March 12, 2021 by Al Williams 38 Comments

Holograms aren’t new, but a desktop machine that spits them out could be available soon, presuming LitiHolo’s Kickstarter pans out. The machine will have a $1600 retail price and fits in a two-foot square. It can generate 4×5 inch holograms with 1mm hogels (the holo equivalent of a pixel).

The machine allows for 23 view zones per hogel and can create moving holograms with a few seconds of motion — like the famous kiss-blowing holograms.

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Scratch-Built Rolling Tool Cabinet Is A Metalworking Skill-Builder

March 12, 2021 by Dan Maloney 14 Comments

Yes, rolling tool cabinets in every conceivable shape, size, arrangement of drawers, and even color are readily available commercially, and you probably shouldn’t build your own. But as [Bob] from “Making Stuff” points out, where’s the fun in that?

Still, we can think of plenty of reasons to make your own rolling tool cabinets from scratch. Aside from the obvious benefits of practicing your metalworking skills and putting your tools to good use, rolling your own means you can get exactly what you want. Almost every tool cabinet we’ve purchased has ended up being just a bit sub-optimal in some way — too wide for the available space, or perhaps with drawers a touch too shallow to fit that one oddball tool. Being able to create your own cabinet means you can hit the specs exactly, and as [Bob] shows, it’s not even that hard if you have the right tools.

The build starts on [Bob]’s CNC plasma cutter, a shop-built machine that’s seen several upgrades over the years. The plasma cutter makes quick work of cutting the drawer blanks from sheet steel, complete with slots to make forming the sheets into drawers easy. The frame of the cabinet is steel tubing, which is welded up and filled in with more sheet steel. Full-extension ball-bearing slides are added to the sides to support the drawers; we have to admit that welding what appears to be zinc-coated steel makes us nervous, but we assume [Bob] took precautions against the potential for toxic fumes.

The video below shows the whole build process and shows off the very sharp-looking final product. It also puts us very much in the mood to build our own plasma cutter.

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Keep Cool With This Open Source AVR Fan Controller

March 12, 2021 by Tom Nardi 12 Comments

We’ve all got projects kicking around that we haven’t had time to document for our own purposes, let alone expose to the blinding light of the Internet. There are only so many hours in a day, and let’s face it, building the thing is a lot more fun than taking pictures of it. It took [Matthew Millman] the better part of a decade to combine everything he’s learned over the years to finally document the definitive version of his open source intelligent fan controller, but looking at the final result, we’re glad he did.

At the heart of this board is an ATmega328P, but don’t call it an Arduino. [Matthew] makes it very clear that if you want to hack around with the code for this project, you’re going to need to not only have a programmer for said chip, but know your way around AVR-GCC. He’s provided pre-built binaries for those content to run with the default settings, but you’ve still got to get it flashed onto the chip yourself. The project is designed to use the common DS18B20 temperature sensor, and as an added bonus, the firmware can even check if yours is a bootleg (spoilers: there’s an excellent chance it is).

Arguably the most interesting feature of this fan controller is its command line interface. Just plug into the serial port on the board, open your terminal emulator, and you’ll have access to a concise set of functions for querying the sensors as well as setting temperature thresholds and RPM ranges for the fans. There’s even a built-in “help” function should you forget a command or the appropriate syntax.

Originally [Matthew] developed this project as a way to control multiple fans inside of a PC case, but naturally, things have changed quite a bit since those early days. While today there’s no shortage of fancy controllers that can handle throttling an array of fans based on the internal temperature of your rig, there’s still something to be said for rolling your own solution. More importantly, there’s certainly other potential uses for a fully open source programmable fan controller.

RIP Lou Ottens, Developer Of The Compact Cassette And More

March 12, 2021 by Jenny List 30 Comments

It’s with sadness that we note the passing at the age of 94 of the long-time Phillips engineer Lou Ottens, who is best known as the originator of the Compact Cassette audio tape format that was so ubiquitous through the later decades of the 20th century. Whether you remember cassettes as the format for 8-bit software, for teenage mixtapes on a Walkman, they began life at his hands in the early 1960s at the Phillips factory in Hasselt, Belgium.

Through a long career with the Dutch electronics company, he was responsible either directly or in part for a string of consumer electronic devices that we would see as ubiquitous over the latter half of the century. Before the cassette he had developed the company’s first portable reel-to-reel tape recorder, and in the 1970s while technical director of their audio division he led the team that would develop the CD. He was reported as saying that his great regret was not beating Sony to the development of the miniature cassette player that would be sold as the Walkman, but we’d suggest that the Walkman would not have been possible without the cassette in the first place.

So next time you handle a cassette tape, spare a thought for Lou, an audio engineer whose work permeated so much of the last half-century.

Thanks [Carl] for the tip.

Images: Lou Ottens by Jordi Huisman CC BY-SA 4.0 and “An early Phillips cassette recorder” by mib18 CC BY-SA 3.0

Historical Hackers: Hero Builds Vending Machines

March 12, 2021 by Al Williams 14 Comments

We tend to think of mechanical contrivances as products of the industrial revolution and true automation as something computers handle. Yet even before computers, automation existed — using timing motors and cams and other mechanical contraptions. But it might surprise you to know that there was actually some sophisticated automation going way back. Really way back, invented in a world without computers, CAD software, or even electricity. For example, around 50 AD an inventor named Hero — sometimes known as Heron — built machines powered by steam and wind. His inventions included vending machines and music players.

It is hard to imagine what kind of music player or, indeed, vending machine you could build in 50AD. Some of Hero’s inventions were used in temples to, for example, dispense holy water. Others were used in theater to do things like automatically lighting a fire or creating thunder effects. There was even an entirely automated puppet show that used knotted ropes to put on a ten-minute production with no human assistance.

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Hackaday Podcast 109: Cars That Suck, A Synth Packed With 555s, X-ray Letter Reading, And Pecking At A PS/2 Keyboard

March 12, 2021 by Mike Szczys 8 Comments

Hackaday editors Mike Szczys and Elliot Williams riff on the week’s most interesting hacks. It’s hard to imagine a more perfect piece of art than an original Pong circuit board mounted in a shadow box and playable along with some tasty FPGA tricks to capture the original look of the screen. You could make a synth with a 555 timer, but what about using 20 of them for perfect polyphony? We ogle an old video showing off a clever toothed-disc CNC machine for cutting pastry with a water jet. And the episode wouldn’t be complete without looking at the strange tech that goes into making a fan car.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (~60 MB)