2025 One Hertz Challenge: Blinking An LED The Very Old Fashioned Way

August 5, 2025 by 10 Comments

Making an LED blink is usually achieved by interrupting its power supply, This can be achieved through any number of oscillator circuits, or even by means of a mechanical system and a switch. For the 2025 One Hertz Challenge though, [jeremy.geppert] has eschewed such means. Instead his LED is always on, and is made to flash by interrupting its light beam with a gap once a second.

This mechanical solution is achieved via a disk with a hole in it, rotating once a second. This is driven from a gear mounted on a 4.8 RPM geared synchronous motor, and the hack lies in getting those gears right. They’re laser cut from ply, from an SVG generated using an online gear designer. The large gear sits on the motor and the small gear on the back of the disk, which is mounted on a bearing. When powered up it spins at 60 RPM, and the LED flashes thus once a second.

We like this entry for its lateral thinking simplicity. The awesome 2025 One Hertz Challenge is still ongoing, so there is still plenty of time for you to join the fun!

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Get Your Tickets For Supercon 2025 Now!

August 5, 2025 by 3 Comments

The wait is over — once this post hits the front page, ticket sales for the 2025 Hackaday Supercon will officially be live!

As is tradition, we’ve reserved 100 tickets priced at $148 (plus fees) for what we like to call the True-Believers. Those are the folks that are willing to sign up even without knowing who will be speaking or what this year’s badge looks like. Once those are sold out, the regular admission tickets will cost $296 (plus fees). We might be slightly biased, but even at full price, we like to think Supercon is a screaming deal.

Those who join us in Pasadena, California from October 31st through November 2nd can look forward to a weekend of talks, workshops, demos, and badge hacking. But what’s more, you’ll experience the unique sense of camaraderie that’s produced when you pack hundreds of hardware hackers into an alleyway and ply them with as much caffeine as they can handle. Some treat it like a normal hacker con, others as a social experiment, but nobody thinks of it as anything less than a fantastic time.

We’re still working closely with our friends at Supplyframe, DigiKey, and Framework to put together a full itinerary for Supercon 2025, so stay tuned over the coming weeks as things are finalized. But in the meantime, we’ve got a couple new additions this year that we’re pretty excited about.

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Student Drone Flies, Submerges

August 5, 2025 by 17 Comments

Admit it. You’d get through boring classes in school by daydreaming of cool things you’d like to build. If you were like us, some of them were practical, but some of them were flights of fancy. Did you ever think of an airplane that could dive under the water? We did. So did some students at Aalborg University. The difference is they built theirs. Watch it do its thing in the video below.

As far as we can tell, the drone utilizes variable-pitch props to generate lift in the air and downward thrust in water. In addition to the direction of the thrust, water operations require a lower pitch to minimize drag. We’d be interested in seeing how it is all waterproofed, and we’re unsure how deep the device can go. No word on battery life either. From the video, we aren’t sure how maneuverable it is while submerged, but it does seem to have some control. It wouldn’t be hard to add a lateral thruster to improve underwater operations.

This isn’t the first vehicle of its kind (discounting fictional versions). Researchers at Rutgers created something similar in 2015, and we’ve seen other demonstrations, but this is still very well done, especially for a student project.

We did see a submersible drone built using parts from a flying drone. Cool, but not quite the same.

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What Happens When Lightning Strikes A Plane?

August 5, 2025 by 24 Comments

Lightning is a powerful force, one seemingly capable of great destruction in the right circumstances. It announces itself with a searing flash, followed by a deep rumble heard for miles around.

Intuitively, it might seem like a lightning strike would be disastrous for something like a plane flying at altitude. And yet, while damage is possible, more often than not—a plane will get through a lightning storm unscathed. Let’s explore the physics at play.

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Real-Time Beamforming With Software-Defined Radio

August 5, 2025 by 13 Comments

It is perhaps humanity’s most defining trait that we are always striving to build things better, stronger, faster, or bigger than that which came before. Taller skyscrapers, longer bridges, and computers with more processors, all advance thanks to this relentless persistence.

In the world of radio, we might assume that a better signal simply means adding more power, but performance can also improve by adding more antennas. Not only do more antennas increase gain but they can also be electronically steered, and [MAKA] demonstrates how to do this with a software-defined radio (SDR) phased array.

The project comes to us in two parts. In the first part, two ADALM-Pluto SDR modules are used, with one set to transmit and the other to receive. The transmitting SDR has two channels, one of which has the phase angle of the transmitted radio wave fixed while the other is swept from -180° to 180°. These two waves will interfere with each other at various points along this sweep, with one providing much higher gain to the receiver. This information is all provided to the user via a GUI.

The second part works a bit like the first, but in reverse. By using the two antennas as receivers instead of transmitters, the phased array can calculate the precise angle of arrival of a particular radio wave, allowing the user to pinpoint the direction it is being transmitted from. These principles form the basis of things like phased array radar, and if you’d like more visual representations of how these systems work take a look at this post from a few years ago.

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Spatial Audio In A Hat

August 5, 2025 by 5 Comments

Students from the ECE4760 program at Cornell have been working on a spatial audio system built into a hat. The project from [Anishka Raina], [Arnav Shah], and [Yoon Kang], enables the wearer to get a sense of the direction and proximity of objects in the immediate vicinity with the aid of audio feedback.

The heart of the build is a Raspberry Pi Pico. It’s paired with a TF-Luna LiDAR sensor which is used to identify the range to objects around the wearer. The sensor is mounted on a hat, so the wearer can pan the sensor from side to side to scan the immediate area for obstacles. Head tracking wasn’t implemented in the project, so instead, the wearer uses a potentiometer to indicate to the microcontroller the direction they are facing as they scan. The Pi Pico then takes the LIDAR scan data, determines the range and location of any objects nearby, and creates a stereo audio signal which indicates to the wearer how close those objects are and their relative direction using a spatial audio technique called interaural time difference (ITD).

It’s a neat build that provides some physical sensory augmentation via the human auditory system. We’ve featured similar projects before, too.

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Some renderings of shapes made from lines including triangles and a circle.

2025 One Hertz Challenge: Analog Clock For Microsoft Windows

August 4, 2025 by No comments

Our hacker [glgorman] sent in their submission for the One Hertz Challenge: an analog software clock for Microsoft Windows.

I guess we’d have to say that this particular project is a work-in-progress. There is no final clock, yet. But a number of yak’s have been shaved. For instance, we have code for computing geometric objects without using branch instructions, including points and lines and circles and such.

The notes dive deep into various rabbit holes. At one point we find ourselves computing the angle to the sun in the sky, that we may be able to cast the shadow of the clock hands on our clock face. The notes include miscellaneous source code snippets and various screenshots of geometric renderings which have been achieved so far.

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