Coronavirus Testing Follow-Up: Rapid Immunologic Testing

March 30, 2020 by 12 Comments

When I started writing my recent article on COVID-19 testing, I assumed that I would be doing a compare and contrast sort of article. Like many people, I assumed that the “gold standard” test would be the reverse transcriptase-polymerase chain reaction (RT-PCR) test that I described in some detail. And indeed it is, but it’s not without its problems, such as the lack of certified labs and the need for trained technicians to run the samples. I also assumed there would be another test, a simple serological test that could use antibodies to discern if there was an active or even a previous, resolved infection.

At the time I wrote the first article, I could find no indication of an immunologic test for COVID-19 (more specifically, a test for SARS-Cov-2, the virus that causes COVID-19). But almost as rapidly as the number of COVID-19 cases rises, the news changes, and it appears that simple, rapidly performed antibody tests are now or soon will be available. They likely won’t replace the gold standard RT-PCR test, but they do stand to be a game-changer for the front line providers and the victims of this disease. So it pays to take a quick look at immunoassays for infectious diseases, and learn how they work.

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Vinyl Cutter Migrates From Scrapbooks To Gaskets

March 30, 2020 by 15 Comments

We know it all too well: another smoothly-operating night in the garage easily halted by a broken component. In the late hours of the night, no hardware store will open its doors. And while waiting may reward the patient, creativity may reward those who act now. That’s exactly where [Justin] found himself one evening: with a torn gasket. Not to be dismayed, he turned to his fiancee [Amy] and the two of them managed to design and cut a perfectly fitting replacement gasket on [Amy’s] vinyl cutter in a  mere matter of minutes.

In the video after the break, the two step us through their process in detail. By starting with an image of the existing gasket, they capture a reference image. Some light work in photoshop cleans up everything except the resulting gasket they’re looking for. Finally, sizing “by eye” in the vinyl cutter’s software after measuring an existing dimension gives them sufficient precision to remake a duplicate gasket that’s eye-for-eye indistiguishable from the original.

It seems like we often hear about vinyl-cut gaskets in passing or in the comments, but it’s great to see a team post such a fabulous success story putting them to good use. And in case a plain old’ vinyl cutter blade wont do the trick, why not try running it at ultrasonic speeds?

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Ammo Can Battery; 50 Ah LiFePO4 Clad In Army Green

March 30, 2020 by 23 Comments

For the price of a mid-range Android phone, [Kenneth Finnegan] turned a 50 caliber ammo can into a 50 amp-hour portable power supply. The battery pack uses four 3.5 V LiFePO4 cells wired in series to achieve a nominal 12 V supply that stands in for a traditional lead-acid battery. The angel of second-hand purchases was smiling on this project as the cells were acquired on eBay in unused condition, complete with bus bars and mounting spacers. All it took to fit them in the case was to grind off the spacers’ dovetails on the outer edges.

There are many benefits to Lithium Iron Phosphate chemistry over traditional lead acid and [Kenneth] spells that out in his discussion of the battery management system at work here. While the newer technology has a much better discharge curve than lead-acid, there’s a frightening amount of power density there if these batteries were to have a catastrophic failure. That’s why there are Battery Management Systems and the one in use here is capable of monitoring all four cells individually which explains the small-gauge wires in the image above. It can balance all of the cells to make sure one doesn’t get more juice than the others, and can disconnect the system if trouble is a-brewin’. Continue reading “Ammo Can Battery; 50 Ah LiFePO4 Clad In Army Green” →

Rock Out While You Knock Out Germs

March 29, 2020 by 11 Comments

We don’t know about you, but we’re pretty tired of singing two rounds of “Happy Birthday” or counting Mississippi to 20 each time we wash our hands. It’s difficult to do it without thinking about the reason why, and that’s not good for positivity. If you’d rather have your spirits lifted every time you hit the sink, you need a better soundtrack.

[Deeplocal] made a soap dispenser that gathers one of your top 20 tunes from Spotify and plays it for 20 seconds while you lather. The best part is that the songs don’t start at 0:00 — the code is written to use the preview clip of each one, so you get the algorithmically-determined best part.

Scrubber is a pretty simple build that uses a Raspberry Pi Zero W and a speaker bonnet powered by a LiPo, but we dig it just the same. The switch is adaptable to pretty much any soap dispenser — just stick two pieces of copper tape where they’ll make contact when the pump is pushed down, and solder wires to them. Check out the demo after the break.

We’ve often wondered how much more water we’re using with all the increased hand-washing out there. Adjusting to this apocalypse is arduous for all of us, but the environment is still a concern, so try to remember to turn the water off while you’re not using it. Is anyone out there working on an easy way to adapt home faucets to add motion or foot control? Because that would be awesome right about now.

The nice thing about Scrubber is that you can focus on washing your hands and doing so properly. If you’d rather watch a digital hourglass to pass the time, light up your lockdown lavatory lifestyle with LEDs.

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Can You Print With Highlighter Ink?

March 29, 2020 by 30 Comments

With huge swathes of people either out of work or working from home, many are now attempting all manner of exciting or silly projects in their downtime. [Emily Velasco] is no exception. She decided to explore the feasability of printing with highlighter ink.

It’s a messy business. Wear gloves.

The hack starts with a rather ancient inkjet printer, so old that it works with tractor feed paper. [Emily] set about gutting several highlighter pens and squeezed out the ink reservoirs into a ladle. The printer’s ink cartridge was then filled with the fluid, and a test print was fired off. Upon initial extraction, it appears blank. However, with the aid of a UV light, the printed pattern is revealed. It appears that the inkjet is printing a very faint image, such that the system almost works as an “invisible ink”.

It’s a fun little hack with an old printer, made easier as it lacks the DRM of newer models. It’d probably be quite achievable with a dot-matrix, too. If you’re similarly tinkering in the innards of your peripherals, be sure to let us know. Video after the break.

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Hackaday Links: March 29, 2020

March 29, 2020 by 19 Comments

It turns out that whacking busted things to fix them works as well on Mars as it does on Earth, as NASA managed to fix its wonky “mole” with a little help from the InSight lander’s robotic arm. Calling it “percussive maintenance” is perhaps a touch overwrought; as we explained last week, NASA prepped carefully for this last-ditch effort to salvage the HP³ experiment, and it was really more of a gentle nudge that a solid smack with the spacecraft’s backhoe bucket. From the before and after pictures, it still looks like the mole is a little off-kilter, and there was talk that the shovel fix was only the first step in a more involved repair. We’ll keep an ear open for more details — this kind of stuff is fascinating, and beats the news from Earth these days by a long shot.

Of course, the COVID-19 pandemic news isn’t all bad. Yes, the death toll is rising, the number of cases is still growing exponentially, and billions of people are living in fear and isolation. But ironically, we’re getting good at community again, and the hacker community is no exception. People really want to pitch in and do something to help, and we’ve put together some resources to help. Check out our Hackaday How You Can Help spreadsheet, a comprehensive list of what efforts are currently looking for help, plus what’s out there in terms of Discord and Slack channels, lists of materials you might need if you choose to volunteer to build something, and even a list of recent COVID-19 Hackaday articles if you need inspiration. You’ll also want to check out our calendar of free events and classes, which might be a great way to use the isolation time to better your lot.

Individual hackers aren’t the only ones pitching in, of course. Maybe of the companies in the hacker and maker space are doing what they can to help, too. Ponoko is offering heavy discounts for hardware startups to help them survive the current economic pinch. They’ve also enlisted other companies, like Adafruit and PCBWay, to join with them in offering similar breaks to certain customers.

More good news from the fight against COVID-19. Folding@Home, the distributed computing network that is currently working on folding models from many of the SARS-CoV-2 virus proteins, has broken the exaFLOP barrier and is now the most powerful computer ever built. True, not every core is active at any given time, but the 4.6 million cores and 400,000-plus GPUs in the network pushed it over from the petaFLOP range of computers like IBM’s Summit, until recently the most powerful supercomputer ever built. Also good news is that Team Hackaday is forming a large chunk of the soul of this new machine, with 3,900 users and almost a million work units completed. Got an old machine around? Read Mike Sczcys’ article on getting started and join Team Hackaday.

And finally, just because we all need a little joy in our lives right now, and because many of you are going through sports withdrawal, we present what could prove to be the new spectator sports sensation: marble racing. Longtime readers will no doubt recognize the mad genius of Martin and his Marble Machine X, the magnificent marble-dropping music machine that’s intended as a follow-up to the original Marble Machine. It’s also a great racetrack, and Martin does an amazing job doing both the color and turn-by-turn commentary in the mock race. It’s hugely entertaining, and a great tour of the 15,000-piece contraption. And when you’re done with the race, it’s nice to go back to listen to the original Marble Machine tune — it’s a happy little song for these trying times.

Custom Drill Press Table Eliminates Hassles

March 29, 2020 by 7 Comments

Getting a perfect workshop together, with all the right tools, is a dream for many. A lot of us cobble together what we can with a dremel tool, a soldering iron, and whatever work surface happens to be available in the kitchen or spare bedroom. But even when we finally get a permanent garage or shop to work in, there are still some challenges to overcome with our workspaces. [Workshop From Scratch] was having issues with his drill press, and solved them with this custom build.

Rather than modify an existing press, he first welded a table together from scratch using square tube. From there he set about solving those issues. The first was having to make a large number of adjustments up and down when working on larger pieces. For that he added an electrically adjustable worktop which keeps him from having to make constant adjustments of the press itself. The second improvement over the standard press workspace was adding a cooling system for the cutting tools, saving himself money in bits and allowing quicker drilling.

The finished product looks professional thanks to a quality paint job and, of course, having all the right tools in the workshop in the first place to put something like this together. We all have an idea in our heads about the perfect workshop for our own needs, but don’t forget to think outside the box when it comes to building one yourself.

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