Hackaday editors Elliot Williams and Mike Szczys recount the coolest hacks from the past week. Most clocks keep time with a quartz crystal, but we discuss one that uses a tuning fork… like the kind you use to tune a piano. Ghidra is a powerful reverse engineering tool developed by the NSA that was recently put to good use changing an embedded thermometer display from Celsius to Fahrenheit. We talk turkey on the Texas power grid problems and Tesla’s eMMC failures. And of course there’s some room for nostalgia as we walk down memory lane with the BASIC programming language.
Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Some people like spinach in their salads. Others would prefer it if it never gets near their fork. Still, other folks, like [Almudena Romero], use it for printing pictures, and they’re the folks we’ll focus on today.
Anthotypes are positive images made from plant dyes that fade from light exposure. Imagine you stain your shirt at a picnic and leave it in the sun with a fork covering part of the stain. When you come back, the stain not sheltered by cutlery is gone, but now you have a permanent fork shape logo made from aunt Bev’s BBQ sauce. The science behind this type of printmaking is beautifully covered in the video below the break. You see, some plant dyes are not suitable for light bleaching, and fewer still if you are not patient since stains like blueberry can take a month in the sun.
The video shows how to make your own plant dye, which has possibilities outside of anthotype printing. Since the dye fades in sunlight, it can be a temporary paint, or you could use samples all over your garden to find which parts get lots of sunlight since the most exposed swatches will be faded the most. Think of a low-tech UV meter with logging, but it runs on spinach.
If the science doesn’t intrigue you, the artistic possibilities are equally cool. All the pictures have a one-of-a-kind, wabi-sabi flare. You take your favorite photo, make it monochrome, print it on a transparent plastic sheet, and the ink will shield the dye and expose the rest. We just gave you a tip about finding the sunniest spot outdoors, so get staining.
Younger readers may not recall the days when every mall had a music store — not the kind where tapes and LPs were sold, but the kind where you could buy instruments. These places inevitably had an employee belting out mall-music to all and sundry on an electric organ. And more often than not, the organist was playing a Hammond organ, with the distinct sound of these instruments generated by something similar to this tonewheel organ robot.
Tonewheels are toothed ferromagnetic wheels that are rotated near a pickup coil. This induces a current that can be amplified; alter the tooth profile or change the speed of rotation, and you’ve got control over the sounds produced. While a Hammond organ uses this technique to produce a wide range of sounds, [The Mixed Signal]’s effort is considerably more modest but nonetheless interesting. A stepper motor and a 1:8 ratio 3D-printed gearbox power a pair of shafts which each carry three different tonewheels. The tonewheels themselves are laser-cut from mild steel and range from what look like spur gears to wheels with but a few large lobes. This is a step up from the previous version of this instrument, which used tonewheels 3D-printed from magnetic filament.
Each tonewheel has its own pickup, wound using a coil winder that [TheMixed Signal] previously built. Each coil has a soft iron core, allowing for the addition of one or more neodymium bias magnets, which dramatically alters the tone. The video below shows the build and a demo; skip ahead to 16:10 or so if you just want to hear the instrument play. It’s — interesting. But it’s clearly a work in progress, and we’re eager to see where it goes. Continue reading “Tonewheels Warble In This Organ-Inspired Musical Instrument”→
As the team outlined in a paper published in 2016, the field of plant nanobionics uses nanotechnology to enhance the natural abilities of plants and make them do new tricks. Here’s how this one works: the roots of the spinach plants absorb nitroaromatic compounds such as picric acid from the groundwater, and these transpire up through the stem and into the leaves along with water and other nutrients. When the compounds reach the leaves, they accumulate in the plants’ mesophyll — the inner tissue of the leaves.
A pair of sensors made of single-walled carbon nanotubes are built into the leaves. One sensor is engineered to detect nitroaromatic compounds using near-infrared fluorescent emission, and the other is used as a reference signal. As the the compounds build up in the mesophyll, the IR signal gets stronger. This change is detected by a camera, which triggers an email alert to the researchers within a matter of minutes. After running the experiments with a fancy-pants indium-gallium-arsenide camera, the researchers were able to duplicate the results using a Raspberry Pi and a CCD camera module with the infrared filter removed.
Plants have an ear to the groundwater like none other and absorb a lot of information about the environment around them, so the researchers believe that detecting explosive materials is only the beginning — they could also be harbingers of pollution and other environmental concerns.
The continued spread of Covid-19 has resulted in a worldwide shortage of hospital beds. A temporary hospital isolation ward (translated) was co-developed by the Korea Advanced Institute of Science and Technology (KAIST) and the Korea Institute of Radiological and Medical Sciences (KIRAMS) to help alleviate this problem. We’re not familiar with the logistics and expense of installing traditional temporary hospital facilities, but the figures provided for this inflatable building approach to the problem seem impressive. It takes 14 days to produce one module, a process which presumably could be pipelined. Being 70% lighter and smaller than their rigidly-constructed counterparts, they can be more easily stored and shipped where needed, even by air.
Once on-site, it takes one day to inflate and outfit it with utilities such as electricity, water, and communications. One of these modules, which look like really big inflatable Quonset huts, contains an intensive care unit, four negative-pressure rooms, a nursing station, staff area, changing and bathrooms, and storage. All this in a 450 m2 building 30 m long and 15 m wide. That works out to be almost 2-stories tall, which is confirmed by the photo above.
Now that the design is finished and a functional unit constructed, the goal is to put it into production as soon as possible. Of course, physical hospital facilities are not the only thing in short supply these days — doctors, nursing and support staff, medical supplies, not to mention the vaccinations themselves, are all needed. But hopefully the success of this project can contribute to the global effort of saving lives and getting control of the virus sooner rather than later. The video below is in Korean, but the automatic English subtitles aren’t too bad.
Sticking a Raspberry Pi in a Pelican-style case and calling it a cyberdeck has become something of a meme these days, and while we certainly don’t look down on such projects, we recognize they can get a bit repetitive. But we think this one is unique enough to get a pass. Sure [eizen6] mounted a Pi inside of a rugged waterproof case, but it’s simply serving as a display for the real star of the show: a vintage Atari 800XL computer.
The overall look of the build, from the stenciled Nostromo on the back to the self-destruct warning sticker over the display is a reference to Alien. Partly because both the film and the Atari 800 were released in 1979, but also because [eizen6] says this particular aesthetic is simply the way computers should look. The visual style is also meant to signify that the project embraces the old ways despite the sprinkling of modern technology.
A custom cable lets the 800XL run on USB power.
To that end, retro aficionados will be happy to hear that the Atari appears to be completely unmodified, with [eizen6] going as far as nestling the nearly 40 year old computer in foam rather than permanently mounting it to the case. The various cables for power, video, and data have all been terminated with the appropriate connectors as well, so everything can be easily unplugged should the 8-bit machine need to be returned to more pedestrian use.
In the top half of the case, [eizen6] has mounted the Raspberry Pi 3B+, a seven inch touch screen, a USB hub, and a SIO2SD that allows loading Atari disk images from an SD card. Using a USB capture device, video from the Atari can be shown on the Pi’s display with a simple VLC command. With a USB keyboard plugged into the hub, the Pi can be put to more advanced use should the need arise. It’s also worth noting that, thanks to a custom cable, the Atari is running off of a USB power bank. With a second USB power bank dedicated to running the Pi and its LCD display, this retro cyberdeck is fully mobile.
[Ben’s] build goes above and beyond the usual craft project masks. It uses a laser-cut chipboard frame to fit three HEPA filters, originally designed for the Roomba robotic vacuum cleaner. Two are used for exhalation, while one is used for inhalation. A small blower fan is installed with the intake filter, to provide mild positive pressure when breathing in. The assembly is wrapped up in fabric, using layers of spandex, fleece, and ripstop nylon to provide the best possible seal against the wearer’s face.
It’s a build that should appeal to those who want to breathe cleaner air and also protect others from exhaled particles that can spread respiratory viruses. We’ve seen all kind of masks hit the scene this year; the graphene-impregnated variety is one of the more interesting designs. Still, one can hope that future years lead to less reliance on such measures!
