Hackaday Links: May 24, 2020

We’re saddened to learn of the passing of Gershon Kingsley in December 2019 at the age of 97. The composer and electronic music pioneer was not exactly a household name, but the things he did with the Moog synthesizer, especially the surprise hit “Pop Corn”, which he wrote in 1969, are sure to be familiar. The song has been covered dozens of times, in the process of which the spelling of the name changed to “Popcorn.” We’re most familiar with the 1972 cover by Hot Butter, an earworm from our youth that doesn’t hide the Moog as deeply in the backing instruments as Kingsley did in the original. Or, perhaps you prefer the cover done by a robotic glockenspiel, because robotic glockenspiel.

A few months back, we covered the audacious plan to recover the radio gear from the Titanic. At the time, the potential salvors, Atlanta-based RMS Titanic, Inc., were seeking permission to cut into the submerged remains of the Titanic‘s Marconi room to remove as much of the wireless gear as possible. A federal judge granted permission for the salvage operation last Friday, giving the company the green light to prepare an expedition for this summer. The US government, through the National Oceanic and Atmospheric Administration and the National Park Service, argued strenuously to leave the wreck be and treat it as a tomb for the 1,527 victims. For our part, we had a great discussion about the merits in the comments section of the previous article. Now that it’s a done deal, we’d love to hear what you have to say about this again.

Although life appears to be slowly returning to what passes for normal, that doesn’t mean you might not still have some cycles to spare, especially when the time spent can bolster your skillset. And so if you’re looking to adding FPGAs to your resume, check out this remote lab on FPGA vision systems offered by Bonn-Rhein-Sieg University. The setup allows you to watch lectures, download code examples, and build them on your local computer, and then upload the resulting binaries to real hardware running on the lab’s servers in Germany. It sounds like a great way to get access to FPGA hardware that you’d otherwise have a hard time laying hands on. Or, you know, you could have just come to the 2019 Hackaday Superconference.

Speaking of skill-builders, oscilloscope owners who want to sharpen their skills could do worse than to listen to the advice of a real scope jockey like Allen Wolke. He recently posted a helpful video listing the five most common reasons for your scope giving “wrong” voltage readings. Spoiler alert: the instrument is probably doing exactly what you told it to do. As a scope newbie, we found the insights very helpful, and we can imagine even seasoned users could make simple mistakes like using the wrong probe attenuation or forgetting that scope response isn’t flat across its bandwidth.

Safety tip for the gearheads among us: your jack stands might be unsafe to use. Harbor Freight, the stalwart purveyor of cheap tools, has issued a recall of two different models of its jack stands. It seems that the pawls can kick out under the right conditions, sending the supported load crashing to the ground. This qualifies as a Very Bad Day for anyone unlucky enough to be working underneath when it happens. Defective jack stands can be returned to Harbor Freight for store credit, so check your garage and be safe out there in the shop.

And finally, because everyone loves a good flame war, Ars Technica has come up with a pronunciation guide for common tech terms. We have to admit that most of these are not surprising; few among the technology literate would mispronounce “Linux” or “sudo”. We will admit to a non-fanboy level of ignorance on whether the “X” in “iOS X” was a Roman numeral or not, but learning that the “iOS” part is correctly pronounced as three syllables, not two was a bit shocking. It’s all an exercise in pedantry that reminds us of a mildly heated discussion we had around the secret Hackaday writers’ bunker and whether “a LED” or “an LED” is the correct style. If the Internet was made for anything, it was stuff like this.

CNC Plasma Cutter Filter Gets The Slag Out

No matter what kind of tools and materials you use in your shop, chances are pretty good that some process is going to release something that you don’t want to breathe. Table saw? Better deal with that wood dust. 3D-printer? We’ve discussed fume control ad nauseam. Soldering? It’s best not to inhale those flux fumes. But perhaps nowhere is fume extraction more important than in the metal shop, where vaporized bits of metal can wreak respiratory havoc.

Reducing such risks was [Shane Wighton]’s rationale behind this no-clean plasma cutter filter. Rather than a water table to collect cutting dross, his CNC plasma cutter is fitted with a downdraft table to suck it away. The vivid display of sparks shooting out of the downdraft fans belied its ineffectiveness, though. [Shane]’s idea is based on the cyclonic principle common to woodshop dust collectors and stupidly expensive vacuum cleaners alike. Plastic pipe sections, split in half lengthwise and covered in aluminum tape to make them less likely to catch on fire from the hot sparks, are set vertically in the air path. The pipes are arranged in a series of nested “S” shapes, offering a tortuous path to the spark-laden air as it exits the downdraft.

The video below shows that most of the entrained solids slow down and drop to the bottom of the filter; some still pass through, but testing with adhesive sheets shows the metal particles in the exhaust are much reduced. We like the design, especially the fact that there’s nothing to clog or greatly restrict the airflow.

Looking for more on CNC plasma cutter builds? We’ve got you covered, from just the basics to next-level.

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Enforce Social Distancing With High Voltage

When getting parts together for a one-off project, we often find ourselves with some leftovers on hand. Most of the time these things go in the junk drawer, but [Brad] aka [AtomicZombie] was working on a project which required parts salvaged from several microwave ovens. That left him with enough surplus components to build a social distancing enforcement tool for the modern age; which will deliver a taser-like shock to anyone which violates the new six-foot rule.

The leftover parts in question were built around a high-voltage capacitor, which [Brad] strapped to his back to hold all of the electronics needed for the six-foot electrified hoop. The generator utilizes the output voltage from two magnetrons, but doesn’t start until the operator enters a code on the front control panel, which is about the only safety device on this entire contraption. To get power to the magnetrons a 12 VDC car battery is used with an inverter to get the required input voltage, and towards the end of the video linked below he shows its effectiveness by setting various objects on fire with it.

While this gag project is unlikely to get any actual use, it’s not like any of us around here need an excuse to play with high voltages. [Brad] is also unlikely to need it either; he lives on a secluded 100-acre homestead and has been featured here for some of the projects he built to make his peaceful life a little easier, like a robotic laundry line, mobile chicken coop, and an electric utility tricycle built from an old truck and motorcycle.

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Google And Apple Reveal Their Coronavirus Contact Tracing Plans: We Kick The Tires

Google and Apple have joined forces to issue a common API that will run on their mobile phone operating systems, enabling applications to track people who you come “into contact” with in order to slow the spread of the COVID-19 pandemic. It’s an extremely tall order to do so in a way that is voluntary, respects personal privacy as much as possible, doesn’t rely on potentially vulnerable centralized services, and doesn’t produce so many false positives that the results are either ignored or create a mass panic. And perhaps much more importantly, it’s got to work.

Slowing the Spread

As I write this, the COVID-19 pandemic seems to be just turning the corner from uncontrolled exponential growth to something that’s potentially more manageable, but it’s not clear that we yet see an end in sight. So far, this has required hundreds of millions of people to go into essentially voluntary quarantine. But that’s a blunt tool. In an ideal world, you could stop the disease globally in a couple weeks if you could somehow test everyone and isolate those who have been exposed to the virus. In the real world, truly comprehensive testing is impossible, and figuring out whom to isolate is extraordinarily difficult due to two factors: COVID-19 has a long incubation period during which it is nonetheless transmissible, and some or even most people don’t know they have it. How can you stop what you can’t see, and even when you can detect it, it’s a week too late?

One promising approach is to isolate those people who’ve been in contact with known cases during the stealth contagion period. To do this is essentially to keep a diary of everyone you’ve been in contact with for the last week or two, and then if you eventually test positive for COVID-19, alert them all so that they can keep from infecting others even before they test positive: track and trace. Doctors can do this by interviewing patients who test positive (this is the “contact tracing” we’ve been hearing so much about), but memory is imperfect. Enter a technological solution. Continue reading “Google And Apple Reveal Their Coronavirus Contact Tracing Plans: We Kick The Tires”

Fail Of The Week: How Not To Die Of Boredom During Isolation

They say you can’t actually die from boredom, but put a billion or so people into self-isolation, and someone is bound to say, “Hold my beer and watch this.” [Daniel Reardon]’s brush with failure, in the form of getting magnets stuck up his nose while trying to invent a facial touch reminder, probably wasn’t directly life-threatening, but it does underscore the need to be especially careful these days.

The story begins with good intentions and a small stack of neodymium magnets. [Daniel]’s idea for a sensor to warn one of impending face touches was solid: a necklace with magnetic sensors and wristbands studded with magnets. Sounds reasonable enough; one can easily see a compact system that sounds an alarm when a hand subconsciously crosses into the Danger Zone while going in for a scratch. Lacking any experience in circuits, though, [Daniel] was unable to get the thing working, so he started playing with the magnets instead. One thing led to another, and magnets were soon adorning his earlobes, and then his nostrils. Unfortunately, two magnets became locked on either side of his septum, as did two others meant to neutralize the pull of the first pair. So off [Daniel] went to the emergency department for a magnetectomy.

Of course it’s easy to laugh at someone’s misfortune, especially when self-inflicted. And the now-degaussed [Daniel] seems to be a good sport about the whole thing. But the important thing here is that we all do dumb things, and hackers need to be especially careful these days. We often work with sharp, pointy, sparky, toxic, or flammable things, and if we don’t keep our wits about us, we could easily end up in an ER somewhere. Not only does that risk unnecessary exposure to COVID-19, but it also takes medical resources away from people who need it more than you do.

By all means, we should be hacking away these idle hours. Even if it’s not in support of COVID-19 solutions, continuing to do what we do is key to our mental health and well-being. But we also need to be careful, to not stretch dangerously beyond our abilities, and to remember that the safety net that’s normally there to catch us is full of holes now.

Thanks to [gir.st] for the tip — you actually were the only one to send this in.

Wind Farms In The Night: On-Demand Warning Lights Are Coming

There appears to be no shortage of reasons to hate on wind farms. That’s especially the case if you live close by one, and as studies have shown, their general acceptance indeed grows with their distance. Whatever your favorite flavor of renewable energy might be, that’s at least something it has in common with nuclear or fossil power plants: not in my back yard. The difference is of course that it requires a lot more wind turbines to achieve the same output, therefore affecting a lot more back yards in total — in constantly increasing numbers globally.

Personally, as someone who encounters them occasionally from the distance, I find wind turbines mostly to be an eyesore, particularly in scenic mountainous landscapes. They can add a futuristic vibe to some otherwise boring flatlands. In other words, I can not judge the claims actual residents have on their impact on humans or the environment. So let’s leave opinions and emotions out of it and look at the facts and tech of one issue in particular: light pollution.

This might not be the first issue that comes to mind when thinking about wind farms. But wind turbines are tall enough to require warning lights for air traffic safety, and can be seen for miles, blinking away in the night sky. From a pure efficiency standpoint, this doesn’t seem reasonable, considering how often an aircraft is actually passing by on average. Most of the time, those lights simply blink for nothing, lighting up the countryside. Can we change this?

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Home Safety Monitoring With IoT

Home automation is a popular project to undertake but its complexity can quickly become daunting, especially if you go further than controlling a few lights (or if you’re a renter). To test the waters you may want to start with something like this home safety monitor, which is an IoT device based on an Arduino. It allows remote monitoring of a home for things such as temperature, toxic gasses, light, and other variables, which is valuable even if you don’t need or want to control anything.

The device is built around an Arduino Nano 33 IOT which has WiFi and Bluetooth capabilities as well as some integrated security features. This build features a number of sensors including pressure/humidity, a gas/smoke detector, and a light sensor. To report all of the information it gathers around the home, an interface with Ubidots is configured to allow easy (and secure) access to the data gathered by the device.

The PCB and code for the project are all provided on the project page, and there are a number of other options available if Ubidots isn’t your preferred method of interfacing with the Internet of Things. You might even give Mozilla’s WebThings a shot if you’re so inclined.