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There are plenty of porous materials out there that we’re all readily familiar with. Fabrics and wood are great examples, allowing liquids or gases to pass through to a certain degree—a property which is useful or problematic depending on the application.
Metals, however, are not something we would readily consider to be porous. They are solid, unyielding, and impermeable. However, with the right techniques, it is possible to produce so-called “breathable” steel, which has particularly interesting applications in the molding industry.
Google has patched an Android ADB bug in the May security patch set. If you have a Pixel phone you should already have the patches, and most other major manufacturers should be close behind. Unfortunately, the biggest risk from this patch will be to the vendors who are also the least likely to release timely – or any – security updates.
ADB, the Android Debug Bridge, is the main tool for installing apps during development and debugging apps while they’re running. It can also be used to side-load apps from a PC. While most normal users are unlikely to ever enable it, developers typically do and some power users might when jailbreaking a device or setting parameters not exposed in the Android UI. Debugging can be done locally via USB, or optionally over the network. To protect the device, the user must unlock the Android device and authorize each new debug agent.
Covered by Risky.Biz, a bug introduced in 2020, and present in every Android release since, allowed bypassing authorization entirely if network debugging was enabled and at least one connection had been made to the ADB service in the past. This happens because ADB compares the certificate of the incoming debug connection with the list of saved certificates. If the certificate type does not match — for instance supplying an Ed25519 certificate instead of a RSA certificate — ADB has been incorrectly handling the error code, and allowing the connection.
In most programming languages, false is considered zero, and true is considered anything not zero. The certificate API returns a 1 for a valid match, a zero for an invalid match, and a negative-one for a type mismatch. Negative one is not zero, so when treated as a boolean value, it becomes true.
To exploit the bug, ADB must be enabled in wireless mode, and there must be at least one trusted device in the ADB configuration. For the average user this is an unlikely combination, but for developers, the time to update is now.
To start things off, we’d like to extend a special thanks to everyone who joined us for Hackaday Europe this weekend in Lecco, Italy. It was 48 hours of fascinating talks, incredible badge hacks, and some of the greatest company you could hope for. For those who couldn’t make it in person, we didn’t forget you — expect to hear more about what went down once we get a chance to catch our collective breath.
That’s not the only thing to keep an eye out for in the coming days. This is your reminder that Amazon will be officially ending support for older Kindles in a few days. After May 20th, any of the megacorp’s e-readers that were introduced before 2012 will be persona non grata, so you should plan accordingly.
The biggest change is that these older devices won’t be able to buy digital books from Amazon, but you can still use them offline, and the fantastic Calibre makes it a breeze to load up content from other sources. To be perfectly honest, we’d advise any Kindle user to decouple their device from the Amazon mothership by using Calibre or even jailbreaking it and installing KOReader, so the end of official support is fine by us. In fact, if a surge of unsupported Kindles brings more attention and users to those projects, that suits us just fine.
The HP-41C analog on my phone gives the right answer.
Three resistors in parallel: 4.7 k,Ω 22 kΩ, and 3.3 kΩ. Quick! What’s the equivalent value? You can estimate it, of course, but if you want the actual 1.8 kΩ (approximately) answer, you probably reached for some kind of calculating aid. I have two slide rules on my desk, and plenty more a few steps away, but I don’t use them much, honestly. I have a very old HP-41C — arguably the best calculator ever made — but I am usually afraid to use it as it is almost 50 years old and difficult to repair. I also have an HP-28S on my desk, a replica HP-41C, and a few others in desk drawers. There are also dozens of calculators on my desktop computer, my phone –including the official HP Prime app — and the web browser.
I often see newer calculators from HP, like the Prime G2, or “new” HP-like calculators like the ones from SwissMicros, and think I should pick one up. Well, technically, HP licensed their calculators to Moravia, so even a “real” HP calculator isn’t from HP anymore. But, in the end, I always realize that my need for a physical calculator is so diminished that I can’t justify buying anything new, and I can barely even spring for a $10 one at the thrift store unless it is a real collectible.
Mind you, I’m not talking about RPN versus algebraic. I could say the same thing for TI, Casio, or Sharp calculators. I just don’t know why I need one anymore, even though I still, for some strange reason, want them.
The Prime seems impressive, if I could ever find time to finish reading the manual.
For the record, I did use an HP-41C to check the resistor math, but it was in the form of an app on my phone, not a real calculator. On the same computer I’m writing this on, I have HP-41C emulators, the Prime emulator, and a bunch of other calculators. Yet I still pick up my phone and use the familiar key layout of the HP-41C. I don’t know why. The replica 41C, unfortunately, has a landscape-oriented keyboard, so while I like it, it doesn’t satisfy my finger’s muscle memory.
Which leads to this Ask Hackaday. Do you use a calculator? Why? If you don’t, do you use a fake calculator on your phone or computer? Or do you just send your math to Google or Wolfram? I suspect some of the answer will be generational. I was in high school before calculators started showing up in schools, but they took over quickly.
There is something satisfying about having a purpose-built device to do your math. No long boot sequence. No switching apps. No messages coming in while you are typing in numbers. For the ultimate convenience, you could wear it on your wrist. The Apollo mission that docked with a Russian spacecraft carried an HP-65, and nine early Space Shuttle missions used an HP-41C. But even astronauts now don’t have a standard-issue calculator. Pilots sometimes use electronic E6Bs, but many still use the mechanical version.
Of course, I do collect slide rules, so maybe I just need to accept that calculators are yet another tech relic to collect. But someone is still buying them. I’d like to be one of them.
While Artemis II was primarily a demonstration flight of the architecture NASA plans to use for future lunar missions, it was also an excellent excuse for the crew to snap some photos of the Moon and Earth with the benefit of modern camera technology. If you’ve been looking forward to seeing more of the crew’s images, you’re in luck, as thousands of new images have recently been released.
Now we don’t mean to beat up on the folks at NASA, but browsing through these images, we couldn’t help but be reminded of an article we saw on PetaPixel that discussed the space agency’s haphazard approach to sharing images online.
It’s really more like an unsorted file dump than anything, made worse by the fact that you have to access it through a government website that looks and performs like it was designed in the early 2000s. There’s even a prominent button that attempts to load a gallery feature that relies on the long-deprecated Adobe Flash. It would be nice to see the situation improved by the time astronauts actually touch down on the lunar surface, but we wouldn’t count on it.
Speaking of old tech, we’ve been following the resurgence of keyboard-equipped smartphones with great interest, as we imagine many of you have been. A recent CNBC article addresses the trend, although it didn’t quite take the nerd contingent into account. We want physical keys so we can work in the terminal and write code without fighting an on-screen keyboard, but of course, that’s not exactly what your average consumer is looking for.
It’s quite the opposite, in fact. A 20-something user referenced in the article explained how the younger generations see the physical keyboard as a way to be less connected to their phones, describing it as “an extra barrier of inconvenience that adds more steps into the thinking process.” If you need us, we’ll be collecting dust in the corner.
We got asked a great question in the mailbag segment on the Podcast this week: are there hacks that we have read about on Hackaday that we use in our everyday life? The answer was absolutely yes, and I loved Tom’s take it often goes the other way – he sees a hack, tests it out, and then writes it up.
But I started looking around the office and I found more examples of projects that were absolutely inspired by projects I had seen on Hackaday, yet weren’t the same. I made a DIY mechanical keyboard because I saw someone else do it. There are a few home-made battery packs that I probably wouldn’t have attempted without having read about someone doing the same thing. I riffed on [Ted Yapo]’s Tritiled project, making a slightly inferior, but workable knockoff, and they’ve been glowing for many years now.
That got me to thinking about reproducing a project versus taking inspiration from it, and though I enjoy both, I’m find myself most often in the “inspiration” mode. I just can’t leave well enough alone, even when I’m fundamentally copying someone. NIH syndrome? Expediency? Probably both, and sometimes with a dose of hubris or feature creep.
Looking back at [Ted]’s TritiLED, though, I found some great examples in both the rebuild and redesign modes on Hackaday.io. [schlion]’s Making Ted Yapo’s TritiLED couldn’t be a clearer example of the former, and it’s great to look over his shoulder and appreciate all the lessons he learned along the way. [Stephan Walter]’s Yet another ultra low power LED is inspired by [Christoph Tack]’s Ultra low power LED, which is in turn inspired by [Ted]’s project, like a conceptual grandchild.
In a way, I look at this like with music: sometimes you play the notes the way they were written down, and sometimes you riff on someone else’s theme. Both are equally valid, and both owe a debt to the upstream source. Is Hackaday the hackers’ jazz club? And which of these modes do you find yourself working in most?
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In this episode, Hackaday Editors Elliot Williams and Tom Nardi start things off by discussing the latest reason that cheap PCB fabrication isn’t quite as cheap as it once was. The conversation will then move on to hacking electronic shelf labels, stylish e-ink status displays, cutting metal at home with high current and a bit of water, a solarpunk message board hiding in a IKEA-style lantern, and pushing NFC out of its comfort zone. From there you’ll hear about a matching transistors, taking pictures of the International Space Station, and Linux on the PS5. They’ll wrap up this week’s episode by going over the surprisingly simple concept behind flow batteries, and learn who’s still using leaded gasoline and why.
Check out the links if you want to follow along, and as always, tell us what you think about this episode in the comments!
