Simple Design Elevates This Mechanical Dot Matrix Display

December 7, 2021 by Dan Maloney 11 Comments

Don’t get us wrong — we love unique displays as much as anyone. But sometimes we stumble across one that’s so unique that we lack the basic vocabulary to describe it. Such is the case with this marble-raising dot-matrix alphanumeric display. But it’s pretty cool, so we’ll give it a shot.

The core — literally — of [Shinsaku Hiura]’s design is a 3D-printed cylinder with a spiral groove in its outside circumference. The cylinder rotates inside a cage with vertical bars; the bars and the grooves are sized to trap 6-mm AirSoft BBs, which are fed into the groove by a port in the stationary base of the display. BBs are fed into the groove at the right position to form characters, which move upwards as the cylinder rotates. Just watch the video below — it explains it far better than words can.

The clever bit is how the BBs are fed into the groove. Rather than have a separate mechanism to gate the feed port, there’s a backlash mechanism that opens the port when the motor powering the drum runs in reverse for a bit. It’s a clever use of cams to get the job done without adding an extra servo, which sort of reminds us of the design parsimony exhibited in his one-servo seven-segment display.

It’s not clear that this would be a very practical display, but that doesn’t stop it from being cool. Although, [Shinsaku Hiura] just released a follow-up video showing a bigger version of this used to display upcoming events from Google Calendar, so perhaps we’re wrong. Continue reading “Simple Design Elevates This Mechanical Dot Matrix Display” →

Retro Reproduction Captures The Style Of The Sol-20

December 7, 2021 by Dan Maloney 26 Comments

In the early years of the computer revolution, a machine like the Sol-20 really stood out. Where most hobbyist machines had front panels that bristled with toggle switches and LEDs, the Sol-20 was a sleek, all-in-one that looked like an electric typewriter in a walnut-trimmed box. Unfortunately, it was also quite expensive, so not that many were sold. This makes them hard enough to find 40 years later that building his own reproduction Sol-20 is about the only way for [Michael Gardi] to have one of his own.

In a lot of ways, the Sol-20 anticipated many of the design elements that would come into play later. Like the Apple and Commodore machines that were coming down the pike, the Sol-20 was intended to be plug and play. [Mike] celebrates that design with a full-size reproduction of the original, concentrating on its unique aesthetic aspects. The reproduction mimics the striking blue case, with its acrylic front panel and walnut sides. The keyboard is also an exact match for the original, in looks if not in function — the capacitive mechanism proved too difficult to replicate, so he opted for a kit using Cherry switches and custom keycaps. [Mike] also used his proven technique for 3D-printing the memorable Sol-20 logo for the front panel, in the correct font and color.

Under the hood, a Raspberry Pi runs an 8080 emulator, which supports a range of virtual devices, including a cassette tape drive and the video output. For fun, [Mike] also imagined what a CRT display for the Sol-20 would have looked like, and added that to his build. It’s a great-looking machine that never was, and we appreciate the attention to detail. We’ve seen that before — his 2/3-scale VT-100 terminal comes to mind, as does his reproduction of a 1960s computer trainer.

Tricked-Out Breadboard Automatically Draws Schematics Of Whatever You Build

December 6, 2021 by Dan Maloney 18 Comments

When it comes to electronic design, breadboarding a circuit is the fun part — the creative juices flow, parts come and go, jumpers build into a tangled mess, but it’s all worth it when the circuit finally comes to life. Then comes the “What have I done?” phase, where you’ve got to backtrack through the circuit to document exactly how you built it. If only there was a better way.

Thanks to [Nick Bild], there is, in the form of the “Schematic-o-matic”, which aims to automate the breadboard documentation process. The trick is using a breadboard where each bus bar is connected to an IO pin on an Arduino Due. A program runs through each point on the breadboard, running a continuity test to see if there’s a jumper connecting them. A Python program then uses the connection list, along with some basic information about where components are plugged into the board, to generate a KiCad schematic.

[Nick] admits the schematics are crude at this point, and that it’s a bit inconvenient to remove some components, like ICs, from the breadboard first to prevent false readings. But this seems like one of those things where getting 80% of the work done automatically and worrying about the rest later is a big win. Plus, we can see a path forward to automatic IC probing, and even measurement of passive components too. But even as it is, it’s a great tool.

Continue reading “Tricked-Out Breadboard Automatically Draws Schematics Of Whatever You Build” →

Hackaday Links: December 5, 2021

December 5, 2021 by Dan Maloney 15 Comments

Sad news from Germany, with the recent passing of a legend in the crypto community: Mr. Goxx, the crypto-trading hamster. The rodent rose to fame in the crypto community for his trades, which were generated at random during his daily exercise routines — his exercise wheel being used like a roulette wheel to choose a currency, and a pair of tunnels determined whether the transaction would be a buy or sell. His trading career was short, having only started this past June, but he was up 20% over that time — that’s nothing to sneeze at. Our condolences to Mr. Goxx’s owners, and to the community which sprung up around the animal’s antics.

It might seem a little early to start planning which conferences you’d like to hit in 2022, but some require a little more lead time than others. One that you might not have heard of is DINACON, the Digital Naturalism Conference, which explores the intersection of technology and the natural world. The con is set for the entire month of July 2022 and will be held in Sri Lanka. It has a different structure than most cons, in that participants attend for a week or so on a rotating basis, much like a biology field station summer session. It sounds like a lot of fun, and the setting couldn’t be more idyllic.

If you haven’t already killed your holiday gift budget buying NFTs, here’s something you might want to consider: the Arduino Uno Mini Limited Edition. What makes it a Limited Edition, you ask? Practically, it’s the small footprint compared to the original Uno and the castellated edges, but there are a bunch of other extras. Each elegant black PCB with gold silk screening is individually numbered and comes in presentation-quality packaging. But the pièce de résistance, or perhaps we should say the cavallo di battaglia, is that each one comes with a hand-signed letter from the Arduino founders. They honestly look pretty sharp, and at $45, it’s really not a bad collector’s piece.

And finally, the YouTube algorithm giveth again, when this infrastructure gem popped up in our feed. You wouldn’t think there’d be much of interest to see in a water main repair, but you’d be wrong, especially when that main is 50′ (15 m) below the surface, and the repair location is 600′ (183 m) from the access hatch. Oh yeah, and the pipe is only 42″ (1 m) in diameter, and runs underneath a river. There’s just so much nope in this one, especially since the diver has to swim into a special turning elbow just to get pointed in the right direction; how he turns around to swim out is not worth thinking about. Fascinating tidbits include being able to see the gravel used to protect the pipe in the riverbed through the crack in the pipe, and learning that big water mains are not completely filled, at least judging by the small air space visible at the top of the pipe. Those with claustrophobia are probably best advised to avoid this one, but it’s still amazing to see how stuff like this is done.

Continue reading “Hackaday Links: December 5, 2021” →

Spatial AI And CV Hack Chat

November 29, 2021 by Dan Maloney No comments

Join us on Wednesday, December 1 at noon Pacific for the Spatial AI and CV Hack Chat with Erik Kokalj!

A lot of what we take for granted these days existed only in the realm of science fiction not all that long ago. And perhaps nowhere is this more true than in the field of machine vision. The little bounding box that pops up around everyone’s face when you go to take a picture with your cell phone is a perfect example; it seems so trivial now, but just think about what’s involved in putting that little yellow box on the screen, and how it would not have been plausible just 20 years ago.

Perhaps even more exciting than the development of computer vision systems is their accessibility to anyone, as well as their move into the third dimension. No longer confined to flat images, spatial AI and CV systems seek to extract information from the position of objects relative to others in the scene. It’s a huge leap forward in making machines see like we see and make decisions based on that information.

To help us along the road to incorporating spatial AI into our projects, Erik Kokalj will stop by the Hack Chat. Erik does technical documentation and support at Luxonis, a company working on the edge of spatial AI and computer vision. Join us as we explore the depths of spatial AI.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 1st at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Science Vs Internet Trolls: Testing Another Kind Of File System

November 24, 2021 by Dan Maloney 39 Comments

No matter what you do or say on the Internet, you’re always doing it wrong. Keyboard commandos are ready to pounce and tell you how it’s “ackchyually” supposed to be done. And so it was of little surprise when [Jason] of Fireball Tools was taken to task by the armchair millwright for his supposedly deficient method of filing metal.

But [Jason] chose to fight back not with words but deeds, building a system to test alternative methods of filing. His filing style is to leave the file in contact with the stock on both the front- and back-strokes, which enraged those who claim that a file must never be dragged back over the workpiece, lest the teeth become dull. The first video below shows the build of the test rig, which leveraged his enormous Cinncinatti shaper as the prime mover, as well as a pneumatic jig to hold the workpiece and imitate both styles of filing. Part two below shows the test rig in action, and [Jason] really outdoes himself with his experimental approach. He tested three different grades of Pferd files — nothing but the best, no expense spared — and did duplicates of each run using both the Internet-approved style and his lazier style.

The result? We won’t spoil that for you, but suffice it to say that the hive mind isn’t always right. And what’s more, [Jason]’s careful myth-busting yielded a few interesting and unexpected results. His channel is full of great shop tips and interesting builds, so check him out if you want to see how metalworking is done.

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A Flip Clock That Flips Up, Not Down

November 24, 2021 by Dan Maloney 3 Comments

The venerable flip clock has become an outsized part of timekeeping culture that belies the simplicity of its mechanism. People collect and restore the electromechanical timepieces with devotion, and even seek to build new kinds of clocks based on split-flap displays. Designs differ, but they all have something in common in their use of gravity to open the leaves and display their numbers.

But what if you turned the flip clock on its head? That’s pretty much what [Shinsaku Hiura] accomplished with a flip clock that stands up the digits rather than flipping them down. The clock consists of three 3D-printed drums that are mounted on a common axle and linked together with gears and a Geneva drive. Each numeral is attached to a drum through a clever cam that makes sure it stands upright when it rotates to the top of the drum, and flops down cleanly as the drum advances. The video below makes the mechanism’s operation clear.

The build instructions helpfully note that “This clock is relatively difficult to make,” and given the extensive troubleshooting instructions offered, we can see how that would be so. It’s not the first time we’ve seen a mechanically challenging design from [Shinsaku Hiura]; this recent one-servo seven-segment display comes to mind.

Continue reading “A Flip Clock That Flips Up, Not Down” →