Wireless Power: Here? Now?

May 27, 2022 by Al Williams 34 Comments

Outside of very small applications, Nikola Tesla’s ideas about transmitting serious power without wires have not been very practical. Sure, we can draw microwatts from radio signals in the air, and if you’re willing to get your phone in just the right spot, you can charge it. But having power sent to your laptop anywhere in your home is still a pipe dream. Sending power from a generating station to a dozen homes without wire is even more fantastic. Or is it? [Paul Jaffe] of the Naval Research Laboratory thinks it isn’t fantastic at all and he explains why in a post on IEEE Spectrum.

Historically, there have been attempts to move lots of power around wirelessly. In 1975, researchers sent power across a lab using microwaves at 50% efficiency. They were actually making the case for beaming energy down from solar power satellites. According to [Jaffe], the secret is to go beyond even microwaves. A 2019 demonstration by the Navy conveyed 400 watts over 300 meters using a laser. Using a tightly confined beam on a single coherent wavelength allows for very efficient photovoltaic cells that can far outstrip the kind we are used to that accept a mix of solar lighting.

Wait. The Navy. High-powered laser beams. Uh oh, right? According to [Jaffe], it is all a factor of how dense the energy in the beam is, along with the actual wavelengths involved. The 400-watt beam, for example, was in a virtual enclosure that could sense any object approaching the main beam and cut power.

Keep in mind that 400 watts isn’t enough to power a hair dryer. Besides, point-to-point transmission with a laser is fine for sending power to a far-flung community but not great for keeping your laptop charged no matter where you leave it.

Still, this sounds like exciting work. While it might not be Tesla’s exact vision, laser transmission might be closer than it seemed just a few years ago. We’ve seen similar systems that employ safety sensors, but they are all relatively low-power. We still want to know what’s going on in Milford, Texas, though.

NYC Hangs Up Its Last Pay Phone

May 26, 2022 by Kristina Panos 48 Comments

It was a melancholy Monday this week in the Big Apple as the last public payphone was uprooted from midtown Manhattan near Times Square and hauled away like so much garbage. That oughta be in a museum, you’re thinking, if you’re anything like us. Don’t worry; that’s exactly where the pair is headed.

This all started in 2014 when mayor de Blasio pledged to move the concept of street-level public utility into the future. Since then, NYC’s payphones have been systematically replaced with roughly 2,000 Link Wi-Fi kiosks that provide free domestic phone calls, device charging, and of course, Internet access. They also give weather, transit updates, and neighborhood news.

There are still a few private payphones around the city, so Superman still has places to change, and Bill and Ted can continue to come home. But if you need to make a phone call and have nowhere to turn, a Link kiosk is the way to go.

Although your Cap’n Crunch whistle hasn’t worked in decades, it’s still a sad day in history for the Jolly Wrencher, whose maiden message was about ye olde red boxen. We’re already seeing pay phones live on as art, so that’s a good sign.

Images via PIX11 and CBS News

Voyager 1 Talks Some Nonsense, But Is Still Working

May 21, 2022 by Jenny List 37 Comments

The Voyager 1 interplanetary probe was launched in 1977 and has now reached interstellar space where it is the furthest-traveled man-made object. It’s hugely exceeded its original mission and continues to return valuable scientific data, but there’s an apparent fault which is leaving its controllers perplexed. Onboard is an attitude control system which keeps the craft’s antennas pointing at Earth, and while it evidently still works (as we’re still in touch with the probe) and other systems are fine, it’s started returning incomprehensible data. Apparently it’s developed a habit of reporting random data, or states the antenna can’t possibly be in.

That a 45 year old computer is still working at all is testament to the skills of its designers, and at 14.5 billion miles away a repair is impossible however much we’d be fascinated to know about the failure modes of old electronics in space. It’s postulated that they might simply live with the fault if the system is still working, issue a software fix, or find some way to use one of the craft’s redundant systems to avoid the problem. Meanwhile we can rest easily in our beds, because we’re still a couple of centuries away from its return as a giant alien sentient machine.

We’ve featured the Voyager program a few times before here at Hackaday, not least when we took a close look at one of its instruments.

Thanks [Jon Woodcock] for the tip.

Hamvention 2022: The Reunion Begins Today

May 20, 2022 by Kristina Panos 7 Comments

Calling all hams! Hamvention 2022 is underway and runs through the weekend at the Greene County Fair and Expo Center in Xenia, Ohio. It’s been three long years since Hamvention took place in person, and this year marks the 70th reunion of what has got to be the largest hamfest in the Midwest. If you’re in the area, you don’t want to miss it. You will need a ticket, though, and here are a few places you pick one up.

Indoors, you’ll find six buildings full of commercial vendors. But outside is where the real fun takes place — the flea market. What treasures will you uncover? There’s only one way to find out.

If you want to get into ham radio, there’s no place like a ham fest to kick off your journey. And if you’ve been poring over the ARRL handbook, you’re in luck, because they’re proctoring ham exams for free at the church across the street on Friday and Saturday.

Can’t make it out for whatever reason, but live close to the fairgrounds? Want to get in the mood on your way there? Tune to 1620AM within a five-ish mile radius to hear weather, traffic, and parking info, plus interviews and other assorted radio fun. If you live nowhere near Ohio, don’t despair — they are livestreaming it on YouTube.

[Note: the Hara Arena, pictured in our awesome Joe Kim artwork, is the old home of Hamvention, and was demolished in 2016. Better head off to the Greene County Fairgrounds instead.]

This Week In Security: IPhone Unpowered, Python Unsandboxed, And Wizard Spider Unmasked

May 20, 2022 by Jonathan Bennett 14 Comments

As conspiracy theories go, one of the more plausible is that a cell phone could be running malicious firmware on its baseband processor, and be listening and transmitting data even when powered off. Nowadays, this sort of behavior is called a feature, at least if your phone is made by Apple, with their Find My functionality. Even with the phone off, the Bluetooth chip runs happily in a low-power state, making these features work. The problem is that this chip doesn’t do signed firmware. All it takes is root-level access to the phone’s primary OS to load a potentially malicious firmware image to the Bluetooth chip.

Researchers at TU Darmstadt in Germany demonstrated the approach, writing up a great paper on their work (PDF). There are a few really interesting possibilities this research suggests. The simplest is hijacking Apple’s Find My system to track someone with a powered down phone. The greater danger is that this could be used to keep surveillance malware on a device even through power cycles. Devices tend to be secured reasonably well against attacks from the outside network, and hardly at all from attacks originating on the chips themselves. Unfortunately, since unsigned firmware is a hardware limitation, a security update can’t do much to mitigate this, other than the normal efforts to prevent attackers compromising the OS.
Continue reading “This Week In Security: IPhone Unpowered, Python Unsandboxed, And Wizard Spider Unmasked” →

PCB Linear Motors For Model Trains

May 19, 2022 by Anne Ogborn 34 Comments

Modeling a railroad is hard. Railroads are large, linear pieces of civil engineering. So many modelers are drawn to the smallest scale they can use. Recently a new scale, named T, at 1:450 has been pushing this barrier. But fitting a reliable mechanical drive mechanism and MCU board in a package this size is a challenge. In practice, even more of a problem is getting reliable electrical contact through a metal wheel on metal track (about the worst possible design for a contact).

T always seemed to us a long way out on the bleeding edge. But all that may have changed. In a recent Hackaday.io writeup, author [Martin] describes a PCB technology based linear motor system to externally drive T scale locomotives.

The system uses 4mm planar coils. The underside of the PCB has another coil, so the effective pitch is 2mm. With microstepping, a step of 0.25mm is possible, and trains run smoothly. Current is 3-400mA. Continue reading “PCB Linear Motors For Model Trains” →

Asahi GPU Hacking

May 16, 2022 by Jonathan Bennett 7 Comments

[Alyssa Rosenzweig] has been tirelessly working on reverse engineering the GPU built into Apple’s M1 architecture as part of the Asahi Linux effort. If you’re not familiar, that’s the project adding support to the Linux kernel and userspace for the Apple M1 line of products. She has made great progress, and even got primitive rendering working with her own open source code, just over a year ago.

Trying to mature the driver, however, has hit a snag. For complex rendering, something in the GPU breaks, and the frame is simply missing chunks of content. Some clever testing discovered the exact failure trigger — too much total vertex data. Put simply, it’s “the number of vertices (geometry complexity) times amount of data per vertex (‘shading’ complexity).” That… almost sounds like a buffer filling up, but on the GPU itself. This isn’t a buffer that the driver directly interacts with, so all of this sleuthing has to be done blindly. The Apple driver doesn’t have corrupted renders like this, so what’s going on?
Continue reading “Asahi GPU Hacking” →