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How Hydraulic Ram Pumps Push Water Uphill With No External Power Input

October 2, 2025 by 25 Comments

Imagine you have a natural stream running through a low-lying area on your farm. It’s a great source of fresh water, only you really need it to irrigate some crops sitting at a higher elevation. The area is quite remote from fixed utilities, complicating the problem.

Your first thought might be to grab a commercial off-the-shelf pump of some sort, along with a fancy solar power system to provide the necessary power to run it. But what if there were a type of pump that could do the job with no external power input at all? Enter the hydraulic ram pump.

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On 3D Scanners And Giving Kinects A New Purpose In Life

October 2, 2025 by 24 Comments

The concept of a 3D scanner can seem rather simple in theory: simply point a camera at the physical object you wish to scan in, rotate around the object to capture all angles and stitch it together into a 3D model along with textures created from the same photos. This photogrammetry application is definitely viable, but also limited in the sense that you’re relying on inferring three-dimensional parameters from a set of 2D images and rely on suitable lighting.

To get more detailed depth information from a scene you’d need to perform direct measurements, which can be done physically or through e.g. time-of-flight (ToF) measurements. Since contact-free ways of measurements tend to be often preferred, ToF makes a lot of sense, but comes with the disadvantage of measuring of only a single spot at a time. When the target is actively moving, you can fall back on photogrammetry or use an approach called structured-light (SL) scanning.

SL is what consumer electronics like the Microsoft Kinect popularized, using the combination of a visible and near-infrared (NIR) camera to record a pattern projected onto the subject, which is similar to how e.g. face-based login systems like Apple’s Face ID work. Considering how often Kinects have been used for generic purpose 3D scanners, this raises many questions regarding today’s crop of consumer 3D scanners, such as whether they’re all just basically Kinect-clones.

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FLOSS Weekly Episode 849: Veilid: Be A Brick

October 1, 2025 by No comments

This week Jonathan talks with Brandon and TC about Veilid, the peer-to-peer networking framework that takes inspiration from Tor, and VeilidChat, the encrypted messenger built on top of it. What was the inspiration? How does it work, and what can you do with it? Listen to find out!

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Lost Techniques: Bond-out CPUs And In Circuit Emulation

October 1, 2025 by 17 Comments

These days, we take it for granted that you can connect a cheap piece of hardware to a microcontroller and have an amazing debugging experience. Stop the program. Examine memory and registers. You can see and usually change anything. There are only a handful of ways this is done on modern CPUs, and they all vary only by detail. But this wasn’t always the case. Getting that kind of view to an actual running system was an expensive proposition.

Today, you typically have some serial interface, often JTAG, and enough hardware in the IC to communicate with a host computer to reveal and change internal state, set breakpoints, and the rest. But that wasn’t always easy. In the bad old days, transistors were large and die were small. You couldn’t afford to add little debugging pins to each processor you produced.

This led to some very interesting workarounds. Of course, you could always run simulators on a larger computer. But that might not work in real time, and almost certainly didn’t have all the external things you wanted to connect to, unless you also simulated them. Continue reading “Lost Techniques: Bond-out CPUs And In Circuit Emulation” →

The Hottest Spark Plugs Were Actually Radioactive

October 1, 2025 by 48 Comments

In the middle of the 20th century, the atom was all the rage. Radiation was the shiny new solution to everything while being similarly poorly understood by the general public and a great deal of those working with it.

Against this backdrop, Firestone Tire and Rubber Company decided to sprinkle some radioactive magic into spark plugs. There was some science behind the silliness, but it turns out there are a number of good reasons we’re not using nuke plugs under the hood of cars to this day.

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A Cut Above: Surgery In Space, Now And In The Future

September 30, 2025 by 3 Comments

In case you hadn’t noticed, we live in a dangerous world. While our soft, fleshy selves are remarkably good at absorbing kinetic energy and healing the damage that results, there are very definite limits to what we humans can deal with, beyond which we’ll need some help. Car crashes, falls from height, or even penetrating trauma such as gunshot wounds — events such as these will often land you in a trauma center where, if things are desperate enough, you’ll be on the operating table within the so-called “Golden Hour” of maximum survivability, to patch the holes and plug the leaks.

While the Golden Hour may be less of a hard limit than the name implies, it remains true that the sooner someone with a major traumatic injury gets into surgery, the better their chances of survival. Here on planet Earth, most urban locations can support one or more Level 1 trauma centers, putting huge swathes of the population within that 60-minute goal. Even in rural areas, EMS systems with Advanced Life Support crews can stabilize the severely wounded until they can be evacuated to a trauma center by helicopter, putting even more of the population within this protective bubble.

But ironically, residents in the highest-priced neighborhood in human history enjoy no such luxury. Despite only being the equivalent of a quick helicopter ride away, the astronauts and cosmonauts aboard the International Space Station are pretty much on their own when it comes to any traumatic injuries or medical emergencies that might crop up in orbit. While the ISS crews are well-prepared for that eventuality, as we’ll see, there’s only so much we can do right now, and we have a long way to go before we’re ready to perform surgery in space

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Ask Hackaday: How Do You Distro Hop?

September 29, 2025 by 36 Comments

If you read “Jenny’s Daily Drivers” or “Linux Fu” here on Hackaday, you know we like Linux. Jenny’s series, especially, always points out things I want to try on different distributions. However, I have a real tendency not to change my distro, especially on my main computer. Yet I know people “distro hop” all the time. My question to you? How do you do it?

The Easy but Often Wrong Answer

Sure, there’s an easy answer. Keep your /home directory on a separate disk and just use it with a new boot image. Sounds easy. But the truth is, it isn’t that easy. I suppose if you don’t do much with your system, that might work. But even if you don’t customize things at the root level, you still have problems if you change desktop environments or even versions of desktop environments. Configuration files change over time. Good luck if you want to switch to and from distros that are philosophically different, like systemd vs old-school init; apparmor vs SELinux. So it isn’t always as simple as just pointing a new distro at your home directory.

One thing I’ve done to try out new things is to use a virtual machine. That’s easy these days. But it isn’t satisfying if your goal is to really switch to a new distro as your daily driver. Continue reading “Ask Hackaday: How Do You Distro Hop?” →