Fighting Food Poisoning With A Patch

Food poisoning is never a fun experience. Sometimes, if you’re lucky, you’ll bite into something bad and realize soon enough to spit it out. Other times, you’ll only realize your mistake much later. Once the tainted food gets far enough into the digestive system, it’s too late. Your only option is to strap in for the ride as the body voids the toxins or pathogens by every means available, perhaps for several consecutive days.

Proper food storage and preparation are the key ways we avoid food poisoning today. However, a new development could give us a further tool in the fight—with scientists finding a way to actively hunt down and destroy angry little pathogens before they can spoil a good meal.

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Hackaday Podcast Episode 352: Visualizing Sound, And Windows 11 Is A Dog

This week, Hackaday’s Elliot Williams and Kristina Panos met up over coffee to bring you the latest news, mystery sound results show, and of course, a big bunch of hacks from the previous seven days or so.

On What’s That Sound, Kristina had no idea what was going on, but [Flippin’ Heck] knew it was a flip dot display, and won a Hackaday Podcast t-shirt! Congratulations!

After that, it’s on to the hacks and such, with not one but two ways of seeing sound.  We also take a look at benchmarking various Windows releases against each other on 12-year-old hardware.

We also talk about painting on floppies and glitching out jpegs in a binary text editor. Finally, we discuss the history and safety of autopilot, and take a look at the humble time clock.

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!

Download in DRM-free MP3 and savor at your leisure.

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How Do PAL And NTSC Really Work?

Many projects on these pages do clever things with video. Whether it’s digital or analogue, it’s certain our community can push a humble microcontroller to the limit of its capability. But sometimes the terminology is a little casually applied, and in particular with video there’s an obvious example. We say “PAL”, or “NTSC” to refer to any composite video signal, and perhaps it’s time to delve beyond that into the colour systems those letters convey.

Know Your Sub-carriers From Your Sync Pulses

A close-up on a single line of composite video from a Raspberry Pi.
A close-up on a single line of composite video from a Raspberry Pi.

A video system of the type we’re used to is dot-sequential. It splits an image into pixels and transmits them sequentially, pixel by pixel and line by line. This is the same for an analogue video system as it is for many digital bitmap formats. In the case of a fully analogue TV system there is no individual pixel counting, instead the camera scans across each line in a continuous movement to generate an analogue waveform representing the intensity of light. If you add in a synchronisation pulse at the end of each line and another at the end of each frame you have a video signal.

But crucially it’s not a composite video signal, because it contains only luminance information. It’s a black-and-white image. The first broadcast TV systems as for example the British 405 line and American 525 line systems worked in exactly this way, with the addition of a separate carrier for their accompanying sound. Continue reading “How Do PAL And NTSC Really Work?”

Linux Fu: Yet Another Shell Script Trick

I’m going to go ahead and admit it: I really have too many tray icons. You know the ones. They sit on your taskbar, perhaps doing something in the background or, at least, giving you fingertip access to some service. You’d think that creating a custom tray icon would be hard, but on Linux, it can be surprisingly simple. Part of the reason is that the Freedesktop people created standards, so you don’t typically have to worry about how it works on KDE vs. GNOME or any of the other desktop environments. That’s a big win.

In fact, it is simple enough that you can even make your own tray icons with a lowly shell script. Well, of course, like most interesting shell scripts, you need some helper programs and, in this case, we’ll use YAD — which is “yet another dialog,” a derivative of Zenity. It’s a GTK program that may cause minor issues if you primarily use KDE, but they are nothing insurmountable.

The program is somewhat of a Swiss army knife. You can use it to make dialogs, file pickers, color selectors, printer dialogs, and even — in some versions — simple web browsers. We’ve seen plenty of tools to make pretty scripts, of course. However, the ability to quickly make good-looking taskbar icons is a big win compared to many other tools.

Docs

Depending on what you want to do, YAD will read things from a command line, a file, or standard input. There are dozens of options, and it is, honestly, fairly confusing. Luckily, [Ingemar Karlsson] wrote the Yad Guide, which is very digestible and full of examples.

Exactly what you need will depend on what you want to do. In my case, I want a tray icon that picks up the latest posts from my favorite website. You know. Hackaday?

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Hands On WIth The Raspberry Pi Compute Module Zero

We are all familiar enough by now with the succession of boards that have come from Raspberry Pi in Cambridge over the years, and when a new one comes out we’ve got a pretty good idea what to expect. The “classic” Pi model B+ form factor has been copied widely by other manufacturers as has their current Compute Module. If you buy the real Raspberry Pi you know you’ll get a solid board with exceptionally good software support.

Every now and then though, they surprise us, with a board that follows a completely different path, which brings us to the one on our bench today. The Compute Module Zero packs the same quad-core RP3 system-on-chip (SoC) and Wi-Fi module as the Pi Zero 2 W with 512 MB of SDRAM onto a tiny 39 mm by 33 mm postage-stamp module. It’s a Pi, but not as you know it, so what is it useful for? Continue reading “Hands On WIth The Raspberry Pi Compute Module Zero”

Hackaday Podcast Ep 351: Hackaday Goes To Chaos Communication Congress

Elliot was of at Europe’s largest hacker convention: Chaos Communication Congress. He had an awesome time, saw more projects than you might think humanely possible, and got the flu. But he pulled through and put this audio tourbook for you.

So if you’ve never been to CCC, give it a listen!

In the far future, all the cool kids will be downloading MP3s of their favorite podcasts.

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Linux Fu: Compose Yourself!

Our computers can display an astonishing range of symbols. Unicode alone defines more than 150,000 characters, covering everything from mathematical operators and phonetic alphabets to emoji and obscure historical scripts. Our keyboards, on the other hand, remain stubbornly limited to a few dozen keys.

On Windows, the traditional workaround involves memorizing numeric codes or digging through character maps. Linux, being Linux, offers something far more flexible: XCompose. It’s one of those powerful, quietly brilliant features that’s been around forever, works almost everywhere, and somehow still feels like a secret.

XCompose is part of the X11 input system. It lets you define compose sequences: short key sequences that produce a Unicode character. Think of it as a programmable “dead key” system on steroids. This can be as simple as programming an ‘E’ to produce a Euro sign or as complex as converting “flower” into a little flower emoji. Even though the system originated with X11, I’ve been told that it mostly works with Wayland, too. So let’s look deeper.

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