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This excellent content from the Hackaday writing crew highlights recurring topics and popular series like Linux-Fu, 3D-Printering, Hackaday Links, This Week in Security, Inputs of Interest, Profiles in Science, Retrotechtacular, Ask Hackaday, Teardowns, Reviews, and many more.

The Physics Lesson I Keep Re-Learning

December 2, 2023 by 69 Comments

One of the most broadly applicable ideas I’ve ever encountered is the concept of impedance matching. If you’re into radio frequency electronics, you’re probably thinking that I mean getting all your circuit elements working to a common characteristic resistance for maximum power transfer. (If you’re not, you’re probably wondering what that jumble of words even means. Fear not!)

But I mean impedance matching in the larger sense. Think about driving a stick-shift automobile. In low gear, the engine has a lot of torque on the wheels, but it can’t spin them all that fast. In high, the wheels turn fastest, but there’s not enough torque to get you started from a standstill. Sometimes you need more force and less motion, other times more motion and less force. The gearbox lets you match the motor’s power to the resistance – the impedance – it’s trying to overcome.

Or think about a cello. The strings are tight, and vibrate with quite a bit of force, but they don’t move all that much. Air, which is destined to carry the sound to your ear, doesn’t take much force to move, and the cello would play louder if it moved more of it. So the bridge conveys the small, but strong, vibrations of the strings and pushes against the top of the resonant box that makes up the body of the instrument. This in turn pushes a lot of air, but not very hard. This is also why speakers have cones, and also why your ear has that crazy stirrup mechanism. Indeed, counting the number of impedance matches between Yo Yo Ma and your brain, I come up with four or five, including electrical matches in the pre-amp.

I mention this because I recently ran into a mismatch. Fans blow air either hard or in large volume. If you pick a fan that’s designed for volume, and put it in a pressure application, it’s like trying to start driving in fifth gear. It stalled, and almost no air got pushed up through the beans in my new “improved” coffee roaster, meaning I had to rebuild it with the old fan, and quick before the next cup was due.

I ran into this mismatch even though I knew there was a possible impedance issue there. I simply don’t have a good intuitive feel how much pressure I needed to push the beans around – the impedance in question – and I bought the wrong fan. But still, knowing that there is a trade-off is a good start. I hope this helps you avoid walking in my footsteps!

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Hackaday Podcast Episode 246: Bypassing Fingerprint Readers Is Easy, Killing Memory Chips Is Hard, Cell Phones Vs Sperm

December 1, 2023 by No comments

It’s the week after Thanksgiving (for some of us) and if you’re sick of leftovers, you’re in luck as Elliot and Dan get together to discuss the freshest and best inter-holiday hacks. We’ll cue up the “Mission: Impossible” theme for a self-destructing flash drive with a surprising sense of self-preservation, listen in on ET only to find out it’s just a meteor, and look for interesting things to do with an old 3D printer. We’ll do a poking around a little in the basement at Tektronix, see how easy it is to spoof biometric security, and get into a love-hate relationship with both binary G-code and bowling balls with strings attached. What do you do with a box full of 18650s? Easy — make a huge PCB to balance them the slow way. Is your cell phone causing a population crisis? Is art real or AI? And what the heck is a cannibal CME? Tune in as we dive into all this and more.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

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This Week In Security: Owncloud, NXP, 0-Days, And Fingerprints

December 1, 2023 by 18 Comments

We’re back! And while the column took a week off for Thanksgiving, the security world didn’t. The most pressing news is an issue in Owncloud, that is already under active exploitation.

The problem is a library that can be convinced to call phpinfo() and include the results in the page response. That function reveals a lot of information about the system Owncloud is running on, including environment variables. In something like a Docker deployment, those environment variables may contain system secrets like admin username and password among others.

Now, there is a bit of a wrinkle here. There is a public exploit, and according to research done by Greynoise Labs, that exploit does not actually work against default installs. This seems to describe the active exploitation attempts, but the researcher that originally found the issue has stated that there is a non-public exploit that does work on default installs. Stay tuned for this other shoe to drop, and update your Owncloud installs if you have them. Continue reading “This Week In Security: Owncloud, NXP, 0-Days, And Fingerprints” →

End Of An Era: Popular Science Shutters Magazine

November 30, 2023 by 69 Comments

Just three years after the iconic magazine abandoned its print version and went all-digital, Popular Science is now halting its subscription service entirely. The brand itself will live on — their site will still run tech stories and news articles, and they have two podcasts that will keep getting new episodes — but no more quarterly releases. While you can’t complain too much about a 151 year run, it’s still sad to see what was once such an influential publication slowly become just another cog in the content mill.

Started as a monthly magazine all the way back in 1872, Popular Science offered a hopeful vision of what was over the horizon. It didn’t present a fanciful version of what the next 100 years would look like, but rather, tried to read the tea leaves of cutting edge technology to offer a glimpse of what the next decade or so might hold. Flip through a few issues from the 1950s and 60s, and you won’t see pulpy stories about humanity conquering the stars or building a time machine. Instead the editors got readers ready for a day when they’d drive cars with warbird-derived turbochargers, and enjoy more powerful tools once transistor technology allowed for widespread use of small brushless motors. It wasn’t just armchair engineering either, issues would often include articles written by the engineers and researchers that were on the front lines. Continue reading “End Of An Era: Popular Science Shutters Magazine” →

Scope GUI Made Easier

November 29, 2023 by 14 Comments

Last time, I assembled a Python object representing a Rigol oscilloscope. Manipulating the object communicates with the scope over the network. But my original goal was to build a little GUI window to sit next to the scope’s web interface. Had I stuck with C++ or even C, I would probably have just defaulted to Qt or maybe FLTK. I’ve used WxWidgets, too, and other than how many “extra” things you want, these are all easy enough to use. However, I had written the code in Python, so I had to make a choice.

Granted, many of these toolkits have Python bindings — PyQt, PySide, and wxPython come to mind. However, the defacto GUI framework for Python is Tkinter, a wrapper around Tk that is relatively simple to use. So, I elected to go with that. I did consider PySimpleGUI, which is, as the name implies, simple. It is attractive because it wraps tkinter, Qt, WxPython, or Remi (another toolkit), so you don’t have to pick one immediately. However, I decided to stay conservative and stuck with Tkinter. PySimpleGUI does have a very sophisticated GUI designer, though.

About Tkinter

The Tkinter toolkit lets you create widgets (like buttons, for example) and give them a parent, such as a window or a frame. There is a top-level window that you’ll probably start with. Once you create a widget, you make it appear in the parent widget using one of three layout methods:

  1. Absolute or relative coordinates in the container
  2. “Pack” to the top, bottom, left, or right of the container
  3. Row and column coordinates, treating the container like a grid

The main window is available from the Tk() method:

import tkinter as tk
root=tk.Tk()
root.title('Example Program')
button=tk.Button(root, text="Goodbye!", command=root.destroy)
button.pack(side='left')
root.mainloop()

That’s about the simplest example. Make a button and close the program when you push it. The mainloop call handles the event loop common in GUI programs.

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CAR T Cell Immunotherapy And The Quiet Hope For A Universal Cancer Treatment

November 27, 2023 by 1 Comment

All of us have to deal with the looming threat of developing cancer during our lifetime, no matter how good our genetics are, or how healthy our lifestyle is. Despite major improvements to the way that we treat and even cure cases of cancer, the reality today is that not all types of cancer are treatable, in many cases there’s the likelihood that one day it will return even after full remission, and chemotherapy in particular comes with potential life-long health issues. Of the most promising new and upcoming treatments, immunotherapy, is decidedly among the most interesting.

With this approach, it is the body’s own immune system that is taught to attack those cancer cells, requiring little more than a few tweaks to T-cells harvested from the patient’s body, after which they’re sent on their merry cancer-killing way.  Yet as simple as this sounds, finding the right characteristics which identify the cancerous cells, and getting a solid and long-lasting immune response is a tough challenge. Despite highly promising results with immunotherapy treatment for non-solid cancers like leukemia – that have resulted in almost miraculous cures – translating this success to other cancer types has so far remained elusive.

New research now shows that changing some characteristics of these modified (chimeric antigen receptors, or CAR) T-cells may be key to making them significantly more long-lived and effective within a patient’s body. Is this the key to making immunotherapy possible for many more cancers?

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Retrotechtacular: Studio Camera Operation, The BBC Way

November 26, 2023 by 11 Comments

If you ever thought that being a television camera operator was a simple job, this BBC training film on studio camera operations will quickly disabuse you of that notion.

The first thing that strikes you upon watching this 1982 gem is just how physical a job it is to stand behind a studio camera. Part of the physicality came from the sheer size of the gear being used. Not only were cameras of that vintage still largely tube-based and therefore huge — the EMI-2001 shown has four plumbicon image tubes along with tube amplifiers and weighed in at over 100 kg — but the pedestal upon which it sat was a beast as well. All told, a camera rig like that could come in at over 300 kg, and dragging something like that around a studio floor all day under hot lights had to be hard. It was a full-body workout, too; one needed a lot of upper-body strength to move the camera up and down against the hydropneumatic pedestal cylinder, and every day was leg day when you had to overcome all that inertia and get the camera moving to your next mark.

Operating a beast like this was not just about the bull work, though. There was a lot of fine motor control needed too, especially with focus pulling. The video goes into a lot of detail on maintaining a smooth focus while zooming or dollying, and shows just how bad it can look when the operator is inexperienced or not paying attention. Luckily, our hero Allan is killing it, and the results will look familiar to anyone who’s ever seen any BBC from the era, from Dr. Who to I, Claudius. Shows like these all had a distinctive “Beeb-ish” look to them, due in large part to the training their camera operators received with productions like this.

There’s a lot on offer here aside from the mechanical skills of camera operation, of course. Framing and composing shots are emphasized, as are the tricks to making it all look smooth and professional. There are a lot of technical details buried in the video too, particularly about the pedestal and how it works. There are also two follow-up training videos, one that focuses on the camera skills needed to shoot an interview program, and one that adds in the complications that arise when the on-air talent is actually moving. Watch all three and you’ll be well on your way to running a camera for the BBC — at least in 1982.

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