Building A New RF Remote From Scratch

April 30, 2020 by 5 Comments

We’ve seen no shortage of projects that use the ESP8266 or ESP32 to add “smart” features to existing home appliances, often by pairing the microcontroller with a radio or IR transmitter. If your device has an existing remote, integrating it into a custom home automation system is often just a matter of getting a few cheap modular components and writing some simple code to glue it all together.

But what if the appliance you want to control doesn’t use a common frequency? That’s a question that [eigma] recently had to answer after finding the remote control for the bedroom ceiling fan was operating at a somewhat unusual 304 MHz. Something like the MAX1472 could probably have been tuned to this frequency, but the chip doesn’t seem to be available in a turn-key module as the popular 315 MHz transmitters are.

There were a few possible options, including using a software defined radio (SDR), but [eigma] didn’t want to spend a fortune on this project or wait months for parts to get shipped from overseas. The most straightforward solution was to design a custom transmitter tuned to the proper frequency using discrete components; something of a dark art to those of us who’ve been spoiled by the high availability of modular components.

What follows is an fascinating look at the design, testing, and troubleshooting of a truly scratch-built transmitter. You won’t find any ICs here, the carrier signal is generated with just a transistor, some carefully measured pieces of wire, and a handful of passive components. By modulating the signal with an ESP32, [eigma] successfully makes the oddball ceiling fan an honorary member of the Internet of Things.

The write-up that [eigma] has done is an absolutely invaluable resource if you ever find yourself in need of rolling a bespoke transmitter. It easily ranks among some of the most informative radio reverse engineering work we’ve covered, and you’d be wise to file this one away for future reference. That said, most of the newer hardware you’re going to run into will probably be utilizing a widely-supported frequency like 433 MHz.

An All Lead Screw 3D Printer You Can Build Yourself

April 30, 2020 by 35 Comments

There was a time when the curious hardware hacker  had to build their own 3D printer, because commercial models were so expensive as to be unaffordable except by well-funded institutions. We’re fortunate then to live in an era in which a good quality off-the-shelf machine can be had without breaking the bank, but that is not to say that home-made 3D printers are a thing of the past. Instead the community of rapid prototyping experimenters continue to push the boundaries of the art, and from that we all benefit. An example comes from [Morgan Lowe], whose 3DLS lead screw driven 3D printer joins the freely downloadable designs to be found on Thingiverse.

If at first sight you think it looks a little familiar, you are correct, as it takes its frame design from the popular AM8 metal frame upgrade for the Anet A8 off-the-shelf printer. It draws heavily from other A8 upgrades, and brings in some parts such as the extruder and bed from the Creality Ender3. This is the beauty of incremental open source, and the result is a belt-free printer that does a decent-looking Benchy on the bench, and as a party piece manages to print a slightly more hairy little plastic boat when suspended at 45 degrees by a rope from the ceiling.

When dipping a toe into the world of home made 3D printers it’s interesting to take a look into some of the earlier Hackaday RepRap posts, and see how far we’ve come.

Wolfram Physics Project Seeks Theory Of Everything; Is It Revelation Or Overstatement?

April 30, 2020 by 74 Comments

Stephen Wolfram, inventor of the Wolfram computational language and the Mathematica software, announced that he may have found a path to the holy grail of physics: A fundamental theory of everything. Even with the subjunctive, this is certainly a powerful statement that should be met with some skepticism.

What is considered a fundamental theory of physics? In our current understanding, there are four fundamental forces in nature: the electromagnetic force, the weak force, the strong force, and gravity. Currently, the description of these forces is divided into two parts: General Relativity (GR), describing the nature of gravity that dominates physics on astronomical scales. Quantum Field Theory (QFT) describes the other three forces and explains all of particle physics. Continue reading “Wolfram Physics Project Seeks Theory Of Everything; Is It Revelation Or Overstatement?” →

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)