Omnibot From The 80s Gets LED Matrix Eyes, Camera

[Ramin assadollahi] has been busy rebuilding and improving an Omnibot 5402, and the last piece of hardware he wanted to upgrade was some LED matrix eyes and a high quality Raspberry Pi camera for computer vision. An Omnibot was something most technical-minded youngsters remember drooling over in the 80s, and when [ramin] bought a couple of used units online, he went straight to the workbench to give the vintage machines some upgrades. After all, the Omnibot 5402 was pretty remarkable for its time, but is capable of much more with some modern hardware. One area that needed improvement was the eyes.

The eyes on the original Omnibot could light up, but that’s about all they were capable of. The first upgrade was installing two 8×8 LED matrix displays to form what [ramin] calls Minimal Expressive Eyes (MEE), powered by a Raspberry Pi. With the help of a 3D-printed adapter and some clever layout, the LED matrix displays fit behind the eye plate, maintaining the original look while opening loads of new output possibilities.

Adding a high quality Raspberry Pi camera with wide-angle lens was a bit more challenging and required and extra long camera ribbon connector, but with the lens nestled just below the eyes, the camera has a good view and isn’t particularly noticeable when the eyes are lit up. Having already upgraded the rest of the hardware, all that remains now is software work and we can’t wait to see the results.

Two short videos of the hardware are embedded below, be sure to give them a peek. And when you’re ready for more 80s-robot-upgrading-action, check out the Hero Jr.

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Random Robot Makes Random Art

For the price of a toothbrush and a small motor with an offset weight, a bristlebot is essentially the cheapest robot that can be built. The motor shakes the toothbrush and the bristle pattern allows the robot to move, albeit in a completely random pattern. While this might not seem like a true robot that can interact with its environment in any meaningful way, [scanlime] shows just how versatile this robot – which appears to only move randomly – can actually be used to make art in non-random ways.

Instead of using a single bristlebot for the project, three of them are built into one 3D printed flexible case where each are offset by 120°, and which can hold a pen in the opening in the center. This allows them to have some control on the robot’s direction of movement. From there, custom software attempts to wrangle the randomness of the bristlebot to produce a given image. Of course, as a bristlebot it is easily subjected to the whims of its external environment such as the leveling of the table and even the small force exerted by the power/communications tether.

With some iterations of the design such as modifying the arms and control systems, she has an interesting art-producing robot that is fairly reliable for its inherently random movements. For those who want to give something like this a try, the code for running the robot and CAD files for 3D printing the parts are all available on the project’s GitHub page. If you’re looking for other bristlebot-style robots that do more than wander around a desktop, be sure to take a look at this line-following bristlebot too.

Thanks to [johnowhitaker] for the tip!

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Hackaday Links: May 9, 2021

Well, that de-escalated quickly. It seems like no sooner than a paper was announced that purported to find photographic evidence of fungi growing on Mars, that the planetary science and exobiology community came down on it like a ton of bricks. As well they should — extraordinary claims require extraordinary evidence, and while the photos that were taken by Curiosity and Opportunity sure seem to show something that looks a lot like a terrestrial puffball fungus, there are a lot of other, more mundane ways to explain these formations. Add to the fact that the lead author of the Martian mushroom paper is a known crackpot who once sued NASA for running over fungi instead of investigating them; the putative shrooms later turned out to be rocks, of course. Luckily, we have a geobiology lab wandering around on Mars right now, so if there is or was life on Mars, we’ll probably find out about it. You know, with evidence.

If you’re a fan of dystopic visions of a future where bloodthirsty robots relentlessly hunt down the last few surviving humans, the news that the New York Police Department decided to stop using their “DigiDog” robot will be a bit of a downer. The move stems from outrage generated by politicians and citizens alike, who dreamt up all sorts of reasons why the NYPD shouldn’t be using this tool. And use it they apparently did —  the original Boston Dynamics yellow showing through the many scuffs and dings in the NYPD blue paint job means this little critter has seen some stuff since it hit the streets in late 2020. And to think — that robot dog was only a few weeks away from filing its retirement papers.

Attention, Commodore fans based in Europe: the Commodore Users Europe event is coming soon. June 12, to be precise. As has become traditional, the event is virtual, but it’s free and they’re looking for presenters.

In a bid to continue the grand Big Tech tradition of knowing what’s best for everyone, Microsoft just announced that Calibri would no longer be the default font in Office products. And here’s the fun part: we all get to decide what the new default font will be, at least ostensibly. The font wonks at Microsoft have created five new fonts, and you can vote for your favorite on social media. The font designers all wax eloquent on their candidates, and there are somewhat stylized examples of each new font, but what’s lacking is a simple way to judge what each font would actually look like on a page of English text. Whatever happened to “The quick brown fox” or even a little bit of “Lorem ipsum”?

And finally, why are German ambulances — and apparently, German medics — covered in QR codes? Apparently, it’s a way to fight back against digital rubberneckers. The video below is in German, but the gist is clear: people love to stop and take pictures of accident scenes, and smartphones have made this worse, to the point that emergency personnel have trouble getting through to give aid. And that’s not to mention the invasion of privacy; very few accident victims are really at their best at that moment, and taking pictures of them is beyond rude. Oh, and it’s illegal, punishable by up to two years in jail. The idea with the QR codes is to pop up a website with a warning to the rubbernecker. Our German is a bit rusty, but we’re pretty sure that translates to, “Hey idiot, get back in your frigging car!” Feel free to correct us on that.

[Editor’s note: “Stop. Rubbernecking kills”.]

Guitar Hero Robot Actually Shreds

Once a popular craze, most of the public has sold or stashed away their plastic video game instruments and forgotten the likes of Guitar Hero and Rockband. Having never been quite satisfied with his scores, [Nick O’Hara] set out to create a robot that could play a Guitar Hero controller. It would be easy enough to use transistors to actuate the buttons or even just a Teensy to emulate a controller and have it play the perfect game, but [Nick] wanted to replicate what it was really like to play. So after burning out a fair number of solenoids (driving them over spec) and learning on his feet, [Nick] slowly began to dial in his robot, Jon Bot Jovi.

The brains of the bot are a Raspberry Pi running some OpenCV-based code that identifies blobs of different colors. The video feed comes from a PS2 via an HDMI capture card. Solenoids are driven via an 8 channel driver board, controlled by the Pi. While it missed a few notes here and there, we loved seeing the strumming solenoid whammy rapidly on the strummer. All in all, it’s a great project, and we love the design of the robot. Whether played by a robot, turned into a synthesizer, or recreated from toy pianos and mechanical keyboards, Guitar Hero controllers offer many hacking opportunities.

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Coffee Cupping Is A Grind — Spectroscopy Could Brew Better Beans

If you’ve ever bought whole coffee beans, chances are good that there was all kinds of information on the bag that led to your decision, like the origin, the roast type, and the flavor notes. Traditionally, coffee grading — that’s judging the aroma of both dry and wet grounds and slurping the coffee evenly across the tongue to determine the flavor profile — is done by humans in a process called cupping. To call it a process is too clinical — it’s really more like a ceremony performed with the grave sincerity that coffee deserves.

A traditional cupping ceremony. Image via Kaldi’s Coffee

There’s an industry standard coffee flavor wheel, so why not leverage that to make a robot that can remove the human bias and possible error of doing things the traditional way? That’s exactly what Demetria, a Columbian-Israeli company is doing.

They’ve developed an AI platform that can determine bean quality as judged by handheld scanners that were born on Kickstarter. The scanner uses near-infrared to look for biochemical markers in the bean, which it uses to match up with a profile backed by the all-knowing coffee flavor wheel.

Demetria is using SCiO scanners and a custom app to judge beans before they’re even roasted, which greatly speeds up the process but makes us wonder how green bean spectroscopy stacks up against roasted beans as judged by humans. You may remember the SCiO, a pocket-sized, connected spectrometer made by Consumer Physics that finally started delivering the goods a few years after funding. If you got your hands on a SCiO, you might like to know that there’s an open project out there to hack them. Sparkfun did a nice, thorough teardown, and it seems to be a well-engineered piece of hardware.

On the one hand, cupping is a tradition and thus may people feel that robbing coffee of this tradition will rob coffee of its soul. On the other hand, cupping is wasteful, as the coffee must be roasted and ground immediately prior to the ceremony and it requires the availability of Q graders who have been trained in the ways of coffee grading.

Want to know more about coffee production? Might as well learn the Retrotechtacular way.

[Main and thumbnail images via Demetria]

Scratch-Built Robot Arm Looks Like Something Off The Factory Floor

[Jeremy Fielding] is rightly impressed with the power and precision of industrial robot arms. The big arms that you see welding cars on assembly lines and the like are engineering feats in their own right, which is why his leap into scratch-building one in the home shop promises to be quite an adventure, and one we’re eager to follow.

From the look of the video below, [Jeremy]’s arm is already substantially complete, so it seems like he’ll be releasing videos that detail how he got to the point where this impressively large and powerful arm took over so much of his shop. He’s not fooling around here — this is a seven-axis articulated arm built from aluminum and powered by AC servos. [Jeremy] allows that some of the structural parts are still 3D-printed prototypes that he’s using to finalize the design before committing to cutting metal, a wise move as he notes that most of the metalworking skills he needs to complete the build are still fairly new to him. It still looks amazing, and we’re looking forward to the rest of the series to see how he got to this point.

We always appreciate [Jeremy]’s enthusiasm and presentation style, and we generally learn a lot from his videos. Whether it’s a CNC table saw, a homebrew dynamometer, or supersonically melting baseballs, his videos are always great to watch.

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Harmonic Drive Uses Compliant Mechanism To Slim Down

[Levi Janssen] has a secret: he doesn’t like harmonic drives. But rather than abandon the torque-amplifying transmission completely, he decided to see about improving them using 3D-printed compliant mechanisms.

For the uninitiated, harmonic drives, also known as strain-wave gears, are a compact, high-torque gearbox that has become popular with “robotic dog” makers and other roboticists. The idea is to have a rigid, internally-toothed outer ring nested around an externally-toothed, flexible cup. A wave generator rotates within the inside cup, stretching it so that it meshes with the outer ring. The two gears differ by only a couple of teeth, meaning that very high gear ratios can be achieved, which makes them great for the joints of robot legs.

[Levi]’s problem with the harmonic drive is that due to the depth of the flexible spline cup, compactness is not among its virtues. His idea is to couple the flex spline to the output of the drive through a flat spring, one that allows flexion as the wave generator rotates but transmits torque efficiently. The entire prototype is 3D-printed, except for the wave generator bearings and stepper motor, and put to the test.

As the video below shows after the excellent introduction to harmonic drives, the concept works, but it’s not without its limitations. Even lightly loaded, the drive made some unpleasant crunching sounds as the PLA springs gave out. We could easily see that being replaced with, say, a steel spring, either machined or cut on a water-jet machine. That might solve the most obvious problem and make [Levi]’s dream of a compact harmonic drive a reality. Of course, we have seen pretty compact strain-wave gears before.

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