Hackaday Links: March 22, 2020

Within the span of just two months, our world of unimaginable plenty and ready access to goods manufactured across the globe has been transformed into one where the bare essentials of life are hard to find at any price. The people on the frontline of the battle against COVID-19 are suffering supply chain pinches too, often at great risk to their health. Lack of proper personal protective equipment (PPE), especially face masks, is an acute problem, and the shortage will only exacerbate the problem as healthcare workers go down for the count. Factories are gearing up to make more masks, but in the meantime, the maker and hacker community can pitch in. FreeSewing, an open-source repository of sewing patterns, has a pattern for a simple face mask called the Fu that can be made quickly by an experienced threadworker. Efficacy of the masks made with that pattern will vary based on the materials used, obviously; a slightly less ad hoc effort is the 100 Million Mask Challenge, where volunteers are given a pattern and enough lab-tested materials to make 100 face masks. If you know how to sew, getting involved might make a difference.

As people around the world wrap their heads around the new normal of social distancing and the loss of human contact, there’s been an understandable spike in interest in amateur radio. QRZ.com reports that the FCC has recorded an uptick in the number of amateur radio licenses issued since the COVID-19 outbreak, and license test prep site HamRadioPrep.com has been swamped by new users seeking to prepare for taking the test. As we’ve discussed, the barrier for entry to ham radio is normally very low, both in terms of getting your license and getting the minimal equipment needed to get on the air. One hurdle aspiring hams might face is the cancellation of so-called VE testing, where Volunteer Examiners administer the written tests needed for each license class. Finding a face-to-face VE testing session now might be hard, but the VEs are likely to find a way to adapt. After all, hams were social distancing before social distancing was cool.

The list of public events that have been postponed or outright canceled by this pandemic is long indeed, with pretty much everything expected to draw more than a handful of people put into limbo. The hacking world is not immune, of course, with many high-profile events scuttled. But we hackers are a resourceful bunch, and the 10th annual Open Source Hardware Summit managed to go off on schedule as a virtual meeting last week. You can watch the nearly eight-hour livestream while you’re self-isolating. We’re confident that other conferences will go virtual in the near-term too rather than cancel outright.

And finally, if you’re sick of pandemic news and just want some escapist engineering eye candy, you could do worse than checking out what it takes to make a DSLR camera waterproof. We’ve honestly always numbered cameras as among the very least waterproof devices, but it turns out that photojournalists and filmmakers are pretty rough on their gear and expect it to keep working even so. The story here focuses (sorry) on Olympus cameras and lenses, which you’ll note that Takasu-san only ever refers to as “splash-proof”, and the complex system of O-rings and seals needed to keep water away from their innards. For our money, the best part was learning that lenses that have to change their internal volume, like zoom lenses, need to be vented so that air can move in and out. The engineering needed to keep water out of a vented system like that is pretty impressive.

Is Solar Right For You? Find Out!

Solar panels are revolutionizing the electric power industry, but not everyone is a good candidate for rooftop solar. Obviously people in extreme northern or sothern latitudes aren’t going to be making a ton of energy during the winter compared to people living closer to the equator, for example, but there are other factors at play that are more specific to each individual house. To find out if any one in particular will benefit from solar panels, [Jake] and [Ryan]’s solar intensity sensor will help you find out.

The long-term intensity tracker is equipped with a small solar panel and a data recording device, properly contained in a waterproof enclosure, and is intended to be placed in the exact location that a potential solar installation will be. Once it has finished gathering data, it will help determine if it makes economical sense to install panels given that the roof slope might not be ideal, landscaping may be in the way, or you live in a climate where it rains a lot in the summer during peak production times.

As we move into the future of cheap, reliable solar panels, projects like this will become more and more valuable. If you’re not convinced yet that photovoltaics are the way of the future, though, there are other ways of harnessing that free solar power.

Waterproofing The Best Watch Ever Made

The Casio F-91W is probably the most popular wristwatch ever made. It’s been in production forever, it’s been worn by presidents, and according to US Army intelligence it is “the sign of al-Qaeda”. There’s a lot of history in this classic watch. That said, there is exactly one problem with this watch: it’s barely water resistant. [David] thought he had a solution to this problem, and it looks like he may have succeeded. This classic watch is now waterproof, down to 700 meters of depth. If you’re ever 700 meters underwater, you have bigger problems than a watch that isn’t waterproof.

The basic idea of this hack is to replace the air inside the watch with a liquid. This serves two purposes: first, the front glass won’t fog up. Second, liquids are generally incompressible, or at least only slightly compressible. By replacing the air in the watch with mineral oil, the watch is significantly more water resistant.

Filling a watch with mineral oil is done simply by disassembling the watch, submerging it in a dish of mineral oil, and carefully reassembling the watch. Does it work? Don’t know about this watch, but this was done to another classic Casio watch and tested to 1200 psi. That’s a kilometer underwater, and the watch still worked afterward. We’ll take that as a success, although again if you’re ever a kilometer underwater, you have bigger problems than a broken watch.

This Way To The Ingress: Keeping Stuff Dry And Clean With IP And NEMA

When designing a piece of hardware that has even the faintest chance of being exposed to the elements, it’s best to repeat this mantra: water finds a way. No matter how much you try to shield a project from rain, splashing, or even just humid air, if you haven’t taken precautions to seal your enclosure, I’ll bet you find evidence of water when you open it up. Water always wins, and while that might not be a death knell for your project, it’s probably not going to help. And water isn’t the only problem that outdoor or rough-service installations face. Particle intrusion can be a real killer too, especially in an environment where dust can be conductive.

There’s plenty you can do to prevent uninvited liquid or particulate guests to your outdoor party, but it tends to be easier to prevent the problem at design time than to fix it after the hardware is fielded. So to help you with your design, here’s a quick rundown of some standards for protection of enclosures from unwanted ingress.

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Organic Chemistry Circuits Are Flexible And Work Wet

As circuits find their way into more and more real-world environments, the old standard circuitry isn’t always up to the task. It wasn’t that long ago that a computer needed special power, cooling, and a large room. Now those computers wouldn’t cut it for the top-of-the-line smartphone. However, most modern circuits don’t bend well and don’t like getting wet.

An international team of researchers is developing chemical-based circuitry that uses gold nanoparticles and electrically charged organic molecules to build circuit elements that behave like semiconductor diode junctions. It’s simple to make flexible circuits that don’t mind being wet using this chemical soup.

In an interview with IEEE Spectrum, the developers mentioned that other circuit elements similar to transistors and light sensors should be possible. The circuits aren’t perfect, however. The switching speed needs improvement. Also, while conventional circuits don’t like to get wet, these chemical circuits have difficulties if things get dry. Still, like all technology, things will probably improve over time.

This technology needs a good bit of engineering refinement before it is practical. If you need flexible photosensitive circuits in the near term, you might try here. Meanwhile, waterproof circuitry just needs the right kind of enclosure.

Photo Credit: UNIST/Nature Nanotechnology

Sound Blimp Makes Camera Quieter And Waterproof

soundBlimp

The D-SLR “crunch” sound can be pretty satisfying. Your camera has moving parts and those cell-phone amateurs can eat your shutter actuation. If you’re a professional photographer behind the scenes on a sound stage or at any film shoot, however, your mirror slapping around is loud enough to get you kicked off the set. [Dan Tábar] needed his D800 to keep it down, so he made his own sound blimp to suppress the noise. As an added bonus, it turns out the case is waterproof, too!

[Dan] got the idea from a fellow photographer who was using a prefab Jacobson blimp to snap pictures in sound-sensitive environments. Not wanting to spend $1000, he looked for a DIY alternative. This build uses a Pelican case to house the body of the camera and interchangeable extension tubes to cover lenses of various sizes. [Dan] took measurements and test-fit a paper cutout of his D800 before carving holes into the Pelican case with a Dremel tool. One side got a circular hole for the extension tubes, while the other received a rectangular cut for the camera’s LCD screen and a smaller circle for the viewfinder.

Lexan serves as a window for all of the open ends: LCD, viewfinder, and the lens. [Dan] snaps pictures with a wireless trigger, saving him the trouble of drilling another hole. You can hear the D800 before and after noise reduction in a video after the break, along with a second video of [Dan] trying out some underwater shots. If you’d rather take a trip back in time, there’s always the 3D printed pinhole camera from last week.

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Mini Waterproof LED Lanterns Charge Without Wires

inductive-charge-led-lights

If you’re in search of a flashlight that can stand up to the elements, or simply looking for an easy way to spruce up your pool for those hot summer nights, check out these rechargeable PVC LED lights. Inspired by a post in Make: Magazine featuring Indestructible LED Lanterns, [John Duffy] decided to take the project one step further.

While he liked Make’s iteration of the waterproof lantern, he thought it would be best to permanently seal the lights for maximum durability. Not satisfied with a one-use light, he equipped the PVC lanterns with a single rechargeable AA battery, step-up circuitry to drive the LED, and an inductive charging coil.

His floating, waterproof lights sport a slightly bigger footprint than their predecessors to house the extra electronics, but we think that’s more than a fair trade off considering they can be charged wirelessly.

Place your Digikey/Mouser/Jameco orders now and check out [John’s] how-to video – you just might get some of these built in time for the weekend!

[via HackedGadgets]

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