How Do PAL And NTSC Really Work?

January 7, 2026 by Jenny List 38 Comments

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 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?” →

The Rise And Fall Of The In-Car Fax Machines

January 7, 2026 by Lewin Day 53 Comments

Once upon a time, a car phone was a great way to signal to the world that you were better than everybody else. It was a clear sign that you had money to burn, and implied that other people might actually consider it valuable to talk to you from time to time.

There was, however, a way to look even more important than the boastful car phone user. You just had to rock up to the parking lot with your very own in-car fax machine.

Continue reading “The Rise And Fall Of The In-Car Fax Machines” →

Linux Fu: Yet Another Shell Script Trick

January 6, 2026 by Al Williams 3 Comments

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?

Continue reading “Linux Fu: Yet Another Shell Script Trick” →

How Advanced Autopilots Make Airplanes Safer When Humans Go AWOL

January 6, 2026 by Maya Posch 21 Comments

It’s a cliché in movies that whenever an airplane’s pilots are incapacitated, some distraught crew member queries the self-loading freight if any of them know how to fly a plane. For small airplanes we picture a hapless passenger taking over the controls so that a heroic traffic controller can talk them through the landing procedure and save the day.

Back in reality, there have been zero cases of large airliners being controlled by passengers in this fashion, while it has happened a few times in small craft, but with variable results. And in each of these cases, another person in the two- to six-seater aircraft was present to take over from the pilot, which may not always be the case.

To provide a more reliable backup, a range of automated systems have been proposed and implemented. Recently, the Garmin Emergency Autoland system got its first real use: the Beechcraft B200 Super King Air landed safely with two conscious pilots on board, but they let the Autoland do it’s thing due to the “complexity” of the situation.

Continue reading “How Advanced Autopilots Make Airplanes Safer When Humans Go AWOL” →

Hands On WIth The Raspberry Pi Compute Module Zero

January 5, 2026 by Jenny List 37 Comments

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” →

2025: As The Hardware World Turns

January 5, 2026 by Tom Nardi 30 Comments

If you’re reading this, that means you’ve successfully made it through 2025! Allow us to be the first to congratulate you — that’s another twelve months of skills learned, projects started, and hacks….hacked. The average Hackaday reader has a thirst for knowledge and an insatiable appetite for new challenges, so we know you’re already eager to take on everything 2026 has to offer.

But before we step too far into the unknown, we’ve found that it helps to take a moment and reflect on where we’ve been. You know how the saying goes: those that don’t learn from history are doomed to repeat it. That whole impending doom bit obviously has a negative connotation, but we like to think the axiom applies for both the lows and highs in life. Sure you should avoid making the same mistake twice, but why not have another go at the stuff that worked? In fact, why not try to make it even better this time?

As such, it’s become a Hackaday tradition to rewind the clock and take a look at some of the most noteworthy stories and trends of the previous year, as seen from our rather unique viewpoint in the maker and hacker world. With a little luck, reviewing the lessons of 2025 can help us prosper in 2026 and beyond.

Continue reading “2025: As The Hardware World Turns” →

Hackaday Podcast Ep 351: Hackaday Goes To Chaos Communication Congress

January 2, 2026 by Elliot Williams 1 Comment

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.