WiFi Meets LoRa For Long Range

What do you get when you cross WiFi and LoRa? Researchers in China have been doing this, and they call the result WiLo. They claim to get reliable connections over about half a kilometer. Typical WiFi runs 40 to 60 meters, barring any Pringle’s cans or other exotic tricks.

According to [Michelle Hampson] writing in IEEE Spectrum, the researchers manipulated Wi-Fi’s OFDM multiplexing to emulate LoRa’s chirp-spreading signal. The advantage is that existing WiFi hardware can use the protocol to increase range.

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Towards Solderless PCB Prototyping

When we think of assembling a PCB, we’re almost always thinking about solder. Whether in paste form or on the spool, hand-iron or reflow, some molten metal is usually in the cards. [Stephen Hawes] is looking for a solderless alternative for prototyping, and he shows us the progress he’s made toward going solderless in this video.

His ulterior motive? He’s the designer of the LumenPNP open-source pick-and-place machine, and is toying with the idea of a full assembly based just on this one machine. If you strapped a conductive-glue extruder head on the machine in addition to the parts placer, you’d have a full assembly in one step. But we’re getting ahead of ourselves.

[Stephen] first tries Z-tape, which is really cool stuff. Small deformable metal balls are embedded in a gel-like tape, and conduct in only the Z direction when parts are pushed down hard into the tape. But Z-tape is very expensive, requires a bit of force to work reliably, and [Stephen] finds that the circuits are intermittent. In short, Z-tape is not a good fit for the PNP machine.

But what [Stephen] does find works well is a graphite-based conductive glue. In particular, he likes the Bare Conductive paint. He tries another carbon-based paint, but it’s so runny that application is difficult, while the Bare stuff is thick and sticky. (They won’t tell you their secret formula, but it’s no secret how the stuff is basically made.) That ends up looking very promising, but it’s still pretty spendy, and [Stephen] is looking to make his own conductive paste/paint pretty soon. That’s particularly appealing, because he can control the stickiness and viscosity, and he’ll surely let us in on the secret sauce.

(We’re armchair quarterbacking here, but the addition of a small amount of methyl cellulose and xanthan gum works to turn metal powder into a formable, printable metal clay, so it might make a carbon paste similarly adjustably sticky.)

We love the end-goal here: one machine that can apply a conductive paint and then put the parts into the right place, resulting in a rough-and-ready, but completely hands-off assembly. You probably wouldn’t want to use this technique if the joint resistance was critical, or if you needed the PCB to stand up to abuse. There’s a reason that everyone in industry uses molten metal, after all. But for verifying a quick one-off, or in a rapid-prototyping environment? This would be a dream.

We’ve seen other wacky ways to go solderless before. This one uses laser-cut parts to hold the components on the PCB, for instance. And for simply joining a couple wires together, we have many more solutions, many thanks to you all in the comments!

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Reversing Type 1 Diabetes With A Patient’s Own Stem Cells

Type 1 diabetes is an auto-immune condition whereby the patient’s own immune system attacks the pancreatic islets, destroying them in the process. Since these islets are responsible for producing insulin in response to blood sugar (glucose) levels, the patient is thus required to externally inject insulin for the remainder of their life. That was the expected scenario, but it appears that this form of diabetes may soon be treatable, with one woman now being free of the condition for a year already, as reported in Nature, referencing an article by [Shusen Wang] et al. that describes the treatment and the one-year result.

Most notable with this study is that the researchers didn’t use the regular method to create pluripotent stem cells. These cells were extracted from the patient, to revert back to this earlier developmental stage. They were not modified using genes, but rather singular chemicals (PDF). The advantage of this is that it avoids having to modify the cell’s genomes, which could conceivably cause issues like cancer later on. This was one of the first time that this method was used in a human subject, with islet cells formed and about 1.5 million of them injected into the patient’s abdominal muscles, a novel site for this procedure.

This location made these islets easy to keep track of, and easier to remove in case of any issues compared to the usual injection site within the liver. Fortunately for this woman, no complications occurred and one year later she is still free of any diabetes symptoms. Two other patients in the trial are also seeing very positive results, leaving only the question of whether the auto-immune condition that originally caused the islet destruction still exists. Since this female patient is taking immunosuppressants for a previous liver transplant it’s a hard to thing to judge, especially since we understand the causes behind type 1 diabetes so poorly.

Regardless, this and other trials using pluripotent cells, transplanted islets and more offer the prospect of a permanent treatment for the many people who suffer from type 1 diabetes.

Featured image: “Human induced pluripotent stem cell colony” National Eye Institute/NIH

 

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Hackaday Links: October 6, 2024

Remember that time a giant cylindrical aquarium in a Berlin hotel bar catastrophically failed and left thousands of fish homeless? We sure do, and further recall that at the time, we were very curious about the engineering details of how this structure failed so spectacularly. At the time, we were sure there’d be plenty of follow-up on that score, but life happened and we forgot all about the story. Luckily, a faithful reader named Craig didn’t, and he helpfully ran down a few follow-up articles that came out last year that are worth looking at.

The first is from prosecutors in Berlin with a report offering three possibilities: that the adhesive holding together the acrylic panels of the aquarium failed; that the base of the tank was dented during recent refurbishment; or that the aquarium was refilled too soon after the repairs, leading to the acrylic panels drying out. We’re a little confused by that last one just from an intuitive standpoint, but each of these possibilities seems hand-wavy enough that the report’s executive summary could have been “Meh, Scheiße happens.”

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Tinkering With Klipper: Making The ManiPilator Robotic Arm

[Leo Goldstien]’s entry into the world of robotics has been full of stops and starts. Like many beginners, he found traditional robotics instructions overwhelming and hard to follow, bogged down with dense math that often obscured the bigger picture. So he decided to approach things differently and create something with his own hands. The result? A 3D-printed robotic arm he affectionately calls “ManiPilator.”

This article is the first in a three-part series documenting [Leo]’s hands-on approach to learning robotics from the ground up. Building ManiPilator became an opportunity to learn by doing, and the project took him on a journey of experimenting, failing, and eventually succeeding in tasks that seemed deceptively simple at first glance. Each hurdle provided him with insights that more traditional learning methods hadn’t delivered. Below is one of the videos [Leo] captured, to show one step in the process: doing a check using multiple motors.

To make his project work, [Leo] relied on open-source software like Klipper, piecing together code and hardware in a way that made sense to him. In sharing his story, he offers fellow beginners an approachable perspective on robotics, with practical insights and candid reflections on the challenges and breakthroughs.

[Leo]’s project shows that there’s more than one way to start exploring robotics, and that sometimes the best way to learn is simply to dive in and start building. Follow along with his journey as he tackles the complexities of robotics, one step at a time.

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Tearing Down A Digital Scope From ’78

If you’re a fan of vintage electronics and DIY tinkering, you’ll find this teardown by [Thomas Scherrer] fascinating. In a recent video, he delves into a rare piece of equipment: the Data Lab Transient Recorder DL 901. This device looks like a classic one-channel oscilloscope, complete with all the knobs and settings you’d expect.

The DL 901, made by Data Laboratories Ltd., is a mystery even to [Thomas], who couldn’t find any documentation online. From the DC offset and trigger settings to the sweep time controls, the DL 901 is equipped to handle slow, high-resolution analog-to-digital conversion. The circuitry includes TTL chips and a PMI DAAC 100, a 10-bit digital-to-analog converter. [Thomas] speculates it uses a successive approximation technique for analog-to-digital conversion—a perfect blend of analog finesse and digital processing for its time.

Despite its intriguing features, the DL 901 suffers from a non-responsive analog input system, limiting the teardown to a partial exploration. For those who enjoyed past Hackaday articles on oscilloscope teardowns and analog tech, this one is a treat. Watch the video to see more details and the full process of uncovering this vintage device’s secrets.

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3D Printed Hydrofoil Goes From Model Scale To Human Scale With Flight Controller

Hydrofoils have been around for several decades, but watching a craft slice through the water with almost no wake never get old. In the videos after the break, [rctestflight] showcases his ambitious project: transforming a standup paddleboard into a rideable hydrofoil with active stabilization.

Unlike conventional electric hydrofoil boards that depend on rider skill for balance, [rctestflight] aims to create a self-stabilizing system. He began by designing a small-scale model, complete with servo-controlled ailerons and elevators, dual motors for differential thrust, and a dRehmFlight flight controller. A pair of sonar sensors help the flight controller maintain constant height above the water. The wings are completely 3D printed, with integrated hinges for flight control surfaces slots for wiring and control components. It’s better suited for 3D printing than RC aircraft since it’s significantly less sensitive to weight, allowing for more structural reinforcement. The small scale tests were very successful and allowed [rctestflight] to determine that he didn’t need the vertical stabilizer and rudder.

The full-sized version features a scaled up wing, larger servos and motors attached to an 11-foot standup paddleboard — minus its rear end — mounted on commercially available e-foil booms. A foam battery box stores a hefty LiFePO4 battery, while the electronics from the smaller version are repurposed here. Despite only catching glimpses of this larger setup in action at the end of the video, it promises an excitingly smooth lake ride we would certainly like to experience.

We’ve seen several 3D printed hydrofoils around here, but this promised to be the largest successful attempt. Don’t fail us [Daniel].

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