New Contest: Making Tech At Home

April 30, 2020 by 13 Comments

Put that parts bin to good use and build something! That’s the gist of the Making Tech at Home contest where your inner pack rat can shine by building from the parts you have on hand.

So what are you supposed to build? We’re not particular, we just want it to be cool. Grab everyone’s attention with an awesome project, and then win our hearts with the story of where you found the components.

Daniel Domínguez’s Parts Bin Self Portrait is an excellent example

An excellent example is the Parts Bin Self Portrait seen here that was a runner-up in the Circuit Sculpture contest. [Daniel Domínguez] talks about cutting out his silhouette from a scrap of prototyping board, pulling dev boards out of the parts box, and finding a ceiling fan on the side of the road which ended up donating the wire from the windings of its motor.

Your story is what’s important here. You can build a sleek and beautiful bit of gear that doesn’t look hacky at all — tell us about what the finished project does, but we also need to hear what parts you had on hand, where they came from, and what led you to use them. There is an element of satisfaction when that broken thermostat that you’ve been squirreling way for ten years, or the accidentally ordered reel of 0402 resistors, ends up getting used. Dust off that electronics hoard and get building!

Prizes Sent Out Throughout the Contest

This contest runs until July 28th, but you won’t have to wait that long to score some loot. Thirty entries will win a grab bag of stuff from Digi-Key and we’ll pick a few projects every week as we work toward that number. Help us decide what to send in those grab bags by voting for the gear you like the most.

Once the contest wraps up, three top winners will receive a mega grab bag stuffed with $500 worth of components. You know… to add to your parts bin for all those future builds.

If you’re anything like us, people deliver their broken stuff to you because they’ve heard you build things out of broken electronics. You feel torn about keeping old hardware around, but feel guilty about sending it to the landfill. When you order parts you get multiples just so you have them on hand for the next project. You were made for this competition, and no matter who the prizes go to, we want a look inside your parts bin.

This Animatronic Mouth Mimics Speech With Servos

April 30, 2020 by 12 Comments

Of the 43 muscles that comprise the human face, only a few are actually important to speaking. And yet replicating the movements of the mouth by mechanical means always seems to end up only partly convincing. Servos and linkages can only approximate the complex motions the lips, cheeks, jaw, and tongue are capable of. Still, there are animatronics out there that make a good go at the job, of which this somewhat creepy mechanical mouth is a fine example.

Why exactly [Will Cogley] felt the need to build a mechanical maw with terrifying and fairly realistic fangs is anyone’s guess. Recalling his lifelike disembodied animatronic heart build, it just seems like he pursues these builds for the challenge of it all. But if you thought the linkages of the heart were complex, wait till you see what’s needed to make this mouth move realistically. [Will] has stuffed this pie hole with nine servos, all working together to move the jaw up and down, push and pull the corners of the mouth, raise and lower the lips, and bounce the tongue around.

It all seems very complex, but [Will] explains that he actually simplified the mechanical design to concentrate more on the software side, which is a text-to-speech movement translator. Text input is translated to phonemes, each of which corresponds to a mouth shape that the servos can create. It’s pretty realistic although somewhat disturbing, especially when the mouth is placed in an otherwise cuddly stuffed bear that serenades you from the nightstand; check out the second video below for that.

[Will] has been doing a bang-up job on animatronics lately, from 3D-printed eyeballs to dexterous mechatronic hands. We’re looking forward to whatever he comes up with next — we think.

Continue reading “This Animatronic Mouth Mimics Speech With Servos” →

Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

3D Printering: Will A Resin Printer Retire Your Filament-based One?

April 30, 2020 by 25 Comments

Adding a resin printer to one’s workbench has never looked so attractive, nor been so affordable. Complex shapes with effortlessly great detail and surface finish? Yes, please! Well, photos make the results look effortless, anyway. Since filament-based printers using fused deposition modeling (FDM) get solid “could be better” ratings when it comes to surface finish and small detail resolution, will a trusty FDM printer end up retired if one buys a resin printer?

The short answer is this: for users who already use FDM, a resin-based stereolithography (SLA) printer is not likely to take over. What is more likely to happen is that the filament printer continues to do the same jobs it is good at, while the resin printer opens some wonderful new doors. This is partly because those great SLA prints will come at a cost that may not always justify the extra work.

Let’s go through what makes SLA good, what it needs in return, and how it does and doesn’t fit in with FDM.

Continue reading “3D Printering: Will A Resin Printer Retire Your Filament-based One?” →

Giving Surfaces Their Own Antiviral Coating To Fight Infection

April 30, 2020 by 15 Comments

The use of disinfectants is not a new thing, but a major disadvantage with most common disinfectants is that they are only effective in the short term. After applying bleach, alcohol or other disinfectant to the surface, the disinfectant’s effect quickly fades as the liquid evaporates. Ideally the disinfectant would remain on the surface, ready to disinfect when needed.

According to researchers at the Hong Kong University of Science and Technology (HKUST), the solution may lie in a heat-sensitive coating that releases disinfectant when it’s needed. This Multilevel Antimicrobial Polymer (MAP-1) can remain effective for as long as 90 days, depending on how often the surface is touched or otherwise used.

MAP-1 consists out of polymer strands of a material that prevents viruses and bacteria from attaching to its surface, while disrupting its outside surface. Effectively this has the potential to inactivate (kill) most viruses and harmful bacteria that come into contact with it.

MAP-1 is currently being deployed in Hong Kong, where public places such as schools, malls and sport facilities have had the coating applied. It costs between US $2,600 and US $50,000 to treat an area, which is not cheap, but would be cheaper than shutting down such a facility for regular surface disinfecting.

Although it still has to be determined that MAP-1 is as effective as hoped, it is another example of an antimicrobial surface, a material that is designed to be as incompatible with sustaining viruses and bacteria as possible. In the past copper and its alloys have been commonly used for this purpose, but a polymer coating is obviously more versatile. From the point of view of today’s pandemic, making surfaces incapable of hosting viruses definitely can be regarded as highly necessary.

(Pictured: a MAP-1 coating on a surface, courtesy of HKUST)

Ultrasonic Sound Gun Precisely Aims Your Music

April 30, 2020 by 25 Comments

When listening to music you sometimes cannot avoid the situation where other people get annoyed because they feel it disrupts their important doings or they do not share your taste in avant-garde doom metal. Of course one could just use headphones. But a hackier way would be to build a parametric speaker that focuses soundwaves into a narrow beam like [Shane] did with this ultrasonic sound gun.

As the directivity of a soundwave depends on the size of the source and its frequency, a directed beam can practically only be achieved with ultrasound. Even though we are not able to perceive frequencies above ~20 kHz, the nonlinear properties of air make it possible to hear the audio modulated onto an ultrasonic carrier signal. For his sound gun [Shane] was inspired by another parametric speaker project. It took him some time to get the 555 timer circuit oscillating at the right frequency and he fried a cheap Bluetooth audio module while trying to increase the output volume but in the end, he managed to get everything working. As the project name suggests, he also 3D printed a gun-shaped enclosure. The video below shows that the sound from the gun behaves really similar to a beam of light and can, for example, be bounced off other objects.

If you are looking for other inspiration there is a whole list of cool ultrasonic projects from distance sensors to acoustic levitation.

Continue reading “Ultrasonic Sound Gun Precisely Aims Your Music” →

Classic 8-Bit Computing The Atari Way

April 29, 2020 by 9 Comments

In the classic gaming world, even before the NES arrived on the scene, there was no name more ubiquitous than Atari. Their famous 2600 console sold almost as many units as the Nintendo 64, but was released nearly 20 years prior. In many ways, despite making mistakes that led to the video game crash of the early 80s, Atari was the first to make a path in the video game industry. If you want to explore what the era of 8-bit computing was like in the Atari age, a new resource is compiling all kinds of Atari-based projects.

This site has everything, from assembling Atari 8-bit computers based on the 6502 chip, to programming them in BASIC and assembly, to running official and homebrew games on the hardware itself. This was put together by [Jason H. Moore] who grew up around Atari systems and later, their home computers. He even puts his biomedical experience to use here by designing a game for the 2600 called Gene Medic which can be found at the site as well.

If you grew up in the 70s and 80s and are looking for a bit of Atari nostalgia this site is the place to go. It’s even worth a visit from younger folks as well since the 8-bit world is a lot easier to get immersed in and learn the fundamentals of computer science. Of course, if you want to take it the other direction, it’s possible to modify the old Atari to add a few modern conveniences.

Photo via Evan-Amos

Make It Easier For Your Software Project To Accept Contributions

April 29, 2020 by 30 Comments

[Flameeyes] has heard complaints (and at times, he admits, has complained himself) about big companies not contributing improvements to projects they seem to find useful, or rolling their own implementation rather than use and contribute to an existing code base. Having recently left Google after seven years, he has some insights into some of the reasons big corporations (at least Google, anyway) may sometimes seem to eschew making code contributions, and some of the reasons might come as a surprise.

There are things a corporation can do differently, but there are also some things that can be done on the project’s end to make accepting contributions easier. [Flameeyes] took some time to write out a few pointers on how to make it easier for others (particularly large corporations) to contribute code to a software project.

The biggest issue is the software license. Without one, there is no legal structure to use, distribute, or contribute to the code, and no corporate entity will want to touch it. Google specifically forbids creating patches for projects with either no license, or incompatible licenses. An example of an incompatible license is one that forbids commercial use, because everything a corporation like Google does — even research –is considered a commercial endeavor. In addition, on the corporate side making contributions might trigger a code review process of some kind for some licenses, but not for others. [Flameeyes] suggests the MIT license as one that is acceptable to pretty much everyone with a minimum of fuss. Another caution: if a project’s code resides in an online repository, make sure the repository is licensed as well.

A few other small suggestions (such as maintaining an AUTHORS file to track contributors in a tidy way) rounds out the advice. It sounds simple, but software licensing is so critical to the whole affair that it’s important to get it right — he suggests the REUSE tool for anyone wanting to make sure a project’s licensing is tidy.

[Flameeyes] makes a point that none of this guidance is based on secret or institutional knowledge. Google has a public document detailing exactly how they use and deal with open source, and it’s a solid guide for how to make your project more accepting of contributions from a corporate entity like Google. (Or, if you prefer, a guide on how to set up as many barriers as possible for your project.)

In case you missed it, we just want to remind you that our favorite recent open source project from Google is definitely Pigweed.