Hackaday Links: June 21, 2020

June 21, 2020 by Dan Maloney 19 Comments

When Lego introduced its Mindstorms line in 1998, in a lot of ways it was like a gateway drug into the world of STEM, even though that term wouldn’t be invented for another couple of years. Children and the obsolete children who begat them drooled over the possibility of combining the Lego building system with motors, sensors, and a real computer that was far and away beyond anything that was available at the time. Mindstorms became hugely influential in the early maker scene and was slowly but steadily updated over the decades, culminating with the recently released Mindstorms Robot Inventor kit. In the thirteen years since the last release, a lot has changed in the market, and we Hackaday scribes had a discussion this week about the continued relevancy of Mindstorms in a time when cheap servos, microcontrollers, and a bewildering array of sensors can be had for pennies. We wonder what the readers think: is a kit that burns a $360 hole in your pocket still worth it? Sound off below.

Are you looking for a way to productively fill some spare time? Plenty of people are these days, and Hackaday has quite a deal for them: Hackaday U! This series of online courses will get you up to speed on a wide range of topics, starting tomorrow with Matthew Alt’s course on reverse engineering with Ghidra. Classes meet online once a week for four weeks, with virtual office hours to help you master the topic. Beside reverse engineering, you can learn about KiCad and FreeCad, quantum computing, real-time processing of audio and sensor data, and later in the year, basic circuit theory. We’ve got other courses lined up to fill out the year, but don’t wait — sign up now! Oh, and the best part? It’s on a pay-as-you-wish basis, with all proceeds going to charity. Get smarter, help others while doing it — what’s not to love about that?

Speaking of virtual learning, the GNU Radio Conference will be moving online for its 10th anniversary year. And while it’s good news that this and other cons have been able to retool and continue their mission of educating and growing this community, it’s still a bummer that there won’t be a chance to network and participate in all the fun events such cons offer. Or perhaps there will — it seems like the Wireless Capture the Flag (CTF) event is still going to happen. Billed as “an immersive plot-driven … competition featuring the GNU Radio framework and many other open-source tools, satellite communications, cryptography, and surreal global landscapes,” it certainly sounds like fun. We’d love to find out exactly how this CTF competition will work.

Everyone needs a way to unwind, and sometimes the best way to do that is to throw yourself into a project of such intricacy and delicate work that you’re forced into an almost meditative state by it. We’ve seen beautiful examples of that with the wonderful circuit sculptures of Mohit Bhoite and Jiří Praus, but here’s something that almost defies belief: a painstakingly detailed diorama of a vintage IBM data center. Created by the aptly named [minatua], each piece of this sculpture is a work of art in its own right and represents the “big iron” of the 1400 series of computers from the early 1960s. The level of detail is phenomenal — the green and white striped fanfold paper coming out of the 1403 line printer has tiny characters printed on it, and on the 729 tape drives, the reels spin and the lights flash. It’s incredible, all the more so because there don’t appear to be any 3D-printed parts — everything is scratch built from raw materials. Check it out.

As you can imagine, the Hackaday tip line attracts a fair number of ideas of the scientifically marginal variety. Although we’re not too fond of spammers, we try to be kind to everyone who bothers to send us a tip, but with a skeptical eye when terms like “free energy” come across. Still, we found this video touting to Nikola Tesla’s free energy secrets worth passing on. It’s just how we roll.

And finally, aside from being the first full day of summer, today is Father’s Day. We just want to say Happy Father’s Day to all the dads out there, both those that inspired and guided us as we were growing up, and those who are currently passing the torch to the next generation. It’s not easy to do sometimes, but tackling a project with a kid is immensely important work, and hats off to all the dads who make the time for it.

Hackaday Links: June 14, 2020

June 14, 2020 by Dan Maloney 17 Comments

You say you want to go to Mars, but the vanishingly thin atmosphere, the toxic and corrosive soil, the bitter cold, the deadly radiation that sleets down constantly, and the long, perilous journey that you probably won’t return from has turned you off a little. Fear not, because there’s still a way for you to get at least part of you to Mars: your intelligence. Curiosity, the Mars rover that’s on the eighth year of its 90-day mission, is completely remote-controlled, and NASA would like to add some self-driving capabilities to it. Which is why they’re asking for human help in classifying thousands of images of the Martian surface. By annotating images and pointing out what looks like soil and what looks like rock, you’ll be training an algorithm that one day might be sent up to the rover. If you’ve got the time, give it a shot — it seems a better use of time than training our eventual AI overlords.

We got a tip this week that ASTM, the international standards organization, has made its collection of standards for testing PPE available to the public. With titles like “Standard Test Method for Resistance of Medical Face Masks to Penetration by Synthetic Blood (Horizontal Projection of Fixed Volume at a Known Velocity)”, it seems like the standards body wants to make sure that that homebrew PPE gets tested properly before being put into service. The timing of this release is fortuitous since this week’s Hack Chat features Hiram Gay and Lex Kravitz, colleagues from the Washington University School of Medicine who will talk about what they did to test a respirator made from a full-face snorkel mask.

There’s little doubt that Lego played a huge part in the development of many engineers, and many of us never really put them away for good. We still pull them out occasionally, for fun or even for work, especially the Technic parts, which make a great prototyping system. But what if you need a Technic piece that you don’t have, or one that never existed in the first place? Easy — design and print your own custom Technic pieces. Lego Part Designer is a web app that breaks Technic parts down into five possible blocks, and lets you combine them as you see fit. We doubt that most FDM printers can deal with the fine tolerances needed for that satisfying Lego fit, but good enough might be all you need to get a design working.

Chances are pretty good that you’ve participated in more than a few video conferencing sessions lately, and if you’re anything like us you’ve found the experience somewhat lacking. The standard UI, with everyone in the conference organized in orderly rows and columns, reminds us of either a police line-up or the opening of The Brady Bunch, neither of which is particularly appealing. The paradigm could use a little rethinking, which is what Laptops in Space aims to do. By putting each participant’s video feed in a virtual laptop and letting them float in space, you’re supposed to have a more organic meeting experience. There’s a tweet with a short clip, or you can try it yourself. We’re not sure how we feel about it yet, but we’re glad someone is at least trying something new in this space.

And finally, if you’re in need of a primer on charlieplexing, or perhaps just need to brush up on the topic, [pileofstuff] has just released a video that might be just what you need. He explains the tri-state logic LED multiplexing method in detail, and even goes into some alternate uses, like using optocouplers to drive higher loads. We like his style — informal, but with a good level of detail that serves as a jumping-off point for further exploration.

A Levitating Lamp Without Magnets

June 10, 2020 by Moritz v. Sivers 9 Comments

If you think of levitating objects you probably think about magnets but this is not what [Aaron Hung] used to build his levitating LED lamp. To be fair, his lamp is not really levitating but merely generates the illusion through the principles of tensegrity. We have featured a number of tensegrity structures over the last months but this is maybe the first time somebody has used it to build a daily-use item.

In his instructable [Aaron Hung] points out that according to Earnshaw’s theorem magnetic levitation using static magnetic fields like those of permanent magnets is actually impossible. If you are interested, the Wikipedia article also explains why floating superconductors and the Levitron toy do not contradict this theorem. (TL;DR: they’re dynamic.)

Coming back to [Aaron Hung]’s tensegrity lamp, the construction is rather simple and only requires an Arduino Nano, a Neopixel ring, a 9 V battery some wood or cardboard, and fishing line. The tensegrity part of the lamp consists of two similar pieces of laser-cut wood which are held together by fishing line so that the top part seems to float in mid-air. Normally, tensegrity structures are very fragile so [Aaron Hung] added some extra lines for stability which allowed him to hang the lamp from the top section without collapsing the whole structure. After coding some animations for the Neopixel ring and adding a paper lampshade the project was finished.

We would like to see more tensegrity versions of classic DIY projects and it was fun to see that similar objects were already built from Lego.

[Video after the break].

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Cast Metal From Prints To Solidify Childhood Memories

June 1, 2020 by Kristina Panos 32 Comments

As far as the hacker’s toolbox goes, the 3D printer is way up there in terms of utility. Sure, it takes time to learn the ins and outs of designing, slicing, and extruding, but after that, the world is pretty much your additive oyster. Follow those design dreams, or use it to replace the things that break. The icing on the cake? You can chase those dreams into other materials, because 3D prints can be used to cast metal.

[RetroTech Journal] wanted to fry up some rosette cookies, a Scandinavian delight from his youth that look a lot like fancy, personal funnel cakes. They’re made with special aluminium irons that shape the dough while it fries, as opposed to the jumbled chaos that is funnel cake.

Rosette irons come in a few traditional shapes, but once you get tired of those, it’s up to you to cast them in aluminium. And how would you go about doing that? By creating a firmly-packed sand mold using a mounted 3D print.

In the endlessly entertaining video after the break, [RetroTech Journal] takes you through the entire process from CAD to cookies. It has everything you could possibly want: LEGO stop-motion, claymation, a little bit of cooking, and a whole lot of knowledge. We can’t wait to see what comes next.

We’ve seen quite a few sand casting projects over the years, but this lathe is among the most useful.

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Toilet Paper Chase And Indoor Cycling Race With Unity And Arduino

May 29, 2020 by Sven Gregori 4 Comments

While we’re still far away from returning to a pre-Corona everyday life, people seem to have accepted that toilet paper will neither magically cease to exist, nor become our new global currency. But back at the height of its madness, like most of us, [Jelle Vermandere] found himself in front of empty shelves, and the solution seemed obvious to him: creating a lifelike toilet paper chasing game in hopes to distract the competition.

Using Unity, [Jelle] created a game world of an empty supermarket, with the goal to chase after distribution tubes and collect toilet paper packs into a virtual cart. Inspired by the Wii Wheel, he imitated a shopping cart handle built from — as it appears — a sunshade pole that holds an Arduino and accelerometer in a 3D-printed case as game controller. For an even more realistic feel, he added a sound sensor to the controller, and competing carts to the game, which can be pushed out of the way by simply yelling loud enough. You can witness all of this delightful absurdity in his build video after the break.

From racing shopping carts to racing bicycles

But that’s not all. With the toilet paper situation sorted out, [Jelle] found himself in a different dilemma: a cloud foiled his plans of going for a bicycle ride. In the same manner, he ended up building a cycling racing game, once again with Unity and Arduino. From a 3D-scanned model of himself and his bicycle, to automatically generating tracks on the fly and teaching an AI to ride a bike, [Jelle] clearly doesn’t joke around while he’s joking around.

However, the best part about the game has to be the controller, which is his actual bicycle. Using a magnetic door sensor to detect the speed, and a potentiometer mounted with an obscure Lego construction to the handlebar, it’s at least on par with the shopping cart handle — but judge for yourself in another build video, also attached after the break. The only thing missing now is to level up the difficulty by powering the Arduino with the bicycle itself.

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Hackaday Links: May 17, 2020

May 17, 2020 by Dan Maloney 9 Comments

Consider it the “Scarlet Letter” of our time. An MIT lab is developing a face mask that lights up to alert others when the wearer has COVID-19. The detection technology is based on sensors that were developed for the Ebola virus scare and uses fluorescently tagged DNA fragments freeze-dried onto absorbent strips built into the mask. The chemistry is activated by the moisture in the sputum expelled when the wearer coughs or sneezes while wearing the mask; any SARS-CoV-2 virus particles in the sputum bind to the strips, when then light up under UV. The list of problems a scheme like this entails is long and varied, not least of which is what would possess someone to willingly don one of these things. Still, it’s an interesting technology.

Speaking of intrusive expansions of the surveillance state, Singapore is apparently now using a Boston Dynamics Spot robot to enforce social-distancing rules in its public parks and gardens. The familiar four-legged, bright yellow dog-bot is carrying cameras that are relaying images of park attendees to some sort of image analysis program and are totally not capturing facial or personal data, pinky swear. If people are found to be violating the two-meter rule, Spot will bark out a prerecorded reminder to spread out a bit. How the system differentiates between people who live together who are out getting some fresh air and strangers who should be staying apart, and whether the operators of this have ever seen how this story turns out are open questions.

Those who lived through 9/11 in the United States no doubt remember the deafening silence that descended over the country for three days while every plane in the civil aviation fleet was grounded. One had no idea how much planes contributed to the noise floor of life until they were silenced. So too with the lockdown implemented worldwide to deal with the COVID-19 pandemic, except with the sometimes dramatic reduction in pollution levels. We’ve all seen pictures where people suddenly realize that Los Angeles isn’t necessarily covered by an orange cloud of smog, and that certain mountain ranges are actually visible if you care to look. But getting some hard data is always useful, and these charts show just how much the pollution situation improved in a number of countries throughout the world after their respective lockdowns. For some cities, the official lockdown was a clear demarcation between the old pollution regime and the new, but for some, there was an obvious period before the lockdown was announced where people were obviously curtailing their activity. It’s always interesting pore over data like this and speculated what it all means.

While the in-person aspects of almost every conference under the sun have been canceled, many of them have switched to a virtual meeting that can at least partially make up for the full experience. And coming up next weekend is Virtually Maker Faire, in the slot where Bay Area Maker Faire would normally be offered. The call for makers ends today, so get your proposals in and sign up to attend.

And finally, there aren’t too many times in life you’ll get a chance to get to visualize a number so large that an Evil Empire was named for it. The googol, or 10¹⁰⁰, was a term coined by the nine-year-old nephew of mathematician Edward Kasner when he asked the child for a good name for a really big number. To put the immensity of that number into perspective, The Brick Experiment Channel on YouTube put together an improbably long gear train using Lego pieces we’ve never seen before with a reduction ratio of 10^103.4:1. The gear train has a ton of different power transmission elements in it, from plain spur gears to worm drives and even planetary gears. We found the 2608.5:1 harmonic gear particularly fascinating. There’s enough going on to keep even a serious gearhead entertained, but perhaps not for the 5.2×10⁹¹ years it’ll take to revolve the final gear once. Something, something, heat-death of the universe. [Ed note: prior art, which we were oddly enough thinking of fondly just a few days ago. Synchronicity!]

Open Source Raman Spectrometer Is Cheaper, But Not Cheap

May 12, 2020 by Al Williams 14 Comments

Raman spectrography uses the Raman scattering of photons from a laser or other coherent light beam to measure the vibrational state of molecules. In chemistry, this is useful for identifying molecules and studying chemical bonds. Don’t have a Raman spectroscope? Cheer up! Open Raman will give you the means to build one.

The “starter edition” replaces the initial breadboard version which used Lego construction, although the plans for that are still on the site, as well. [Luc] is planning a performance edition, soon, that will have better performance and, presumably, a greater cost.

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