A sine wave and triangle wave on a black background

2025 One Hertz Challenge: Op-Amp Madness

July 31, 2025 by 7 Comments

Sometimes, there are too many choices in this world. My benchtop function generator can output a sine, square, or saw wave anywhere from 0.01 Hz up to 60 MHz? Way too many choices. At least, that’s what we suspect [Phil Weasel] was thinking when he built this Analog 1 Hz Sinewave Generator.

Rendering of a PCB
A KiCad rendering of [Phil]’s design
[Phil]’s AWG (which in this case stands for Anything as long as it’s a 1 Hz sine Wave Generator) has another unique feature — it’s built (almost) entirely with op-amps. A lot of op-amps (37, by our count of the initial schematic he posted). His design is similar to a Phased Locked Loop (PLL) and boils down to a triangle wave oscillator. While a 1 Hz triangle wave would absolutely satisfy judges of the One Hertz Challenge, [Phil] had set out to make a sine wave. Using a feedback loop and some shaping/smoothing tricks (and more op-amps), he rounded off the sharp peaks into a nice smooth sine wave.

Sometimes we make things much more complicated than we need to, just to see if we can. This is one of those times. Are there much simpler ways to generate a sine wave? Yes — but not exclusively using op-amps! This entry brings stiff competition to the “Ridiculous” category of the 2025 One Hertz Challenge.

When Online Safety Means Surrendering Your ID, What Can You Do?

July 31, 2025 by 108 Comments

A universal feature of traveling Europe as a Hackaday scribe is that when you sit in a hackerspace in another country and proclaim how nice a place it all is, the denizens will respond pessimistically with how dreadful their country really is. My stock response is to say “Hold my beer” and recount the antics of British politicians, but the truth is, the grass is always greener on the other side.

There’s one thing here in dear old Blighty that has me especially concerned at the moment though, and perhaps it’s time to talk about it here. The Online Safety Act has just come into force and is the UK government’s attempt to deal with what they perceive as the nasties on the Internet, and while some of its aspirations may be honourable, its effects are turning out to be a little chilling.

As might be expected, the Act requires providers to ensure their services are free of illegal material, and it creates some new offences surrounding sharing images without consent, and online stalking. Where the concern lies for me is in the requirement for age verification to ensure kids don’t see anything the government things they shouldn’t, which is being enforced through online ID verification. There are many reasons why this is of concern, but I’ll name the three at the top of my list.
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Hexagonal Lighting Brings A Touch Of Elegance To The Workshop

July 31, 2025 by 5 Comments

Sometimes, we’re faced with what should be simple household tasks that we choose to make more difficult. Sure, you could buy a clock, hang it on your wall, and move on with your day, or could spend a week or two building the perfect one. [Nejc Koncan] was in one such situation recently when he needed some new overhead lighting. He wanted hexagonal lights — and since none of the off-the-shelf solutions met his exacting requirements, he built his own.

Unlike most of the cycling RGB hexagonal lighting solutions available on the market, [Nejc] wanted elegant white outlines that he could control via HomeAssistant. After some careful design and quite a bit of trial-and-error, he ended up with a highly modular and very professional-looking installation. The hexagons are constructed from LED strips set into aluminum extrusions, with junction PCBs at each intersection. To complete the look, all of the strips and wiring are hidden by diffusers that slot into the extrusions — and of course, the whole thing is open source.

We see lots of lighting projects here at Hackaday, and even other hexagonal lights — but this might just be one of the most refined. Sometimes it’s worth the extra effort to build a totally over-engineered custom solution.

Hands On: The Hacker Pager

July 31, 2025 by 26 Comments

It should come as no surprise that the hacker community has embraced the Meshtastic project. It’s got a little bit of everything we hold dear: high quality open source software, fantastic documentation, a roll-your-own hardware ethos, and just a dash of counterculture. An off-grid communications network cobbled together from cheap parts, some of which being strategically hidden within the urban sprawl by rogue operators, certainly sounds like the sort of thing you’d read about it in a William Gibson novel.

But while the DIY nature of Meshtastic is one of its most endearing features for folks like us, it can also be seen as one of its weak spots. Right now, the guidance for those looking to get started is to pick a compatible microcontroller development board, 3D print a case for it, screw on an antenna from AliExpress, flash your creation with the latest firmware, and then spend some quality time with the documentation and configuration tools to actually get it on the air. No great challenge for the average Hackaday reader, but a big ask for the weekend adventurer that’s just looking for a way to keep in touch with their friends while camping.

Quality hardware that offers a turn-key experience will be critical to elevating Meshtastic from a hobbyist’s pastime to something that could actually be fielded for applications such as search and rescue. Plus, let’s be honest, even those of us who like to put together our own gadgets can appreciate a more consumer-oriented piece of hardware from time to time. Especially if that hardware happens to be open source and designed to empower the user rather than hold them back.

Enter the Hacker Pager from exploitee.rs. As the name implies, it’s still very much a device intended for hackers — a piece of hardware designed for the halls of DEF CON rather than trekking through the wilderness. But it’s also an important step towards a new generation of Meshtastic hardware that meets the high standard of quality set by the software itself.

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Farewell Shunsaku Tamiya: The Man Who Gave Us The Best Things To Build

July 31, 2025 by 36 Comments

In the formative experiences of most Hackaday readers there will almost certainly be a number of common threads, for example the ownership of a particular game console, or being inspired into engineering curiosity by the same TV shows. A home computer of a TV show may mark you as coming from a particular generation, but there are some touchstones which cross the decades.

Of those, we are guessing that few readers will not at some point have either built, owned, or lusted after a Tamiya model kit at some point over the last many decades, so it’s with some sadness that we note the passing of Mr. Tamiya himself, Shunsaku Tamiya, who has died at the age of 90.

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Robots Are Coming For Your Berry Good Job

July 31, 2025 by 29 Comments

We don’t know if picking blackberries at scale is something people enjoy doing. But if you do, we have bad news. The University of Arkansas wants to put you out of a job in favor of your new robot overlord. It turns out that blackberries in Arkansas alone are a $24 million business. The delicate berries are typically hand-picked.

The robot hand that can do the same job has three soft fingers and tendons made from guitar strings. Each finger has a force sensor at the tip so it can squeeze the berries just right. How much force does it take to grab a blackberry? To find out, researchers placed sensors on the fingers of experienced pickers and used the data to guide their design. Researchers claim they were inspired by the motion of a tulip opening and closing each day.

Your berry picking job is safe for now, though. They don’t have the vision system to actually find the berries. Not yet, anyway. Of course in the meantime, the gripper could be used for anything that needs a delicate touch.

Oddly, everyone seems to want to develop robots to pick agricultural items. We are usually more interested in a different kind of picking.

Closeup of WOPR interface on Raspberry Pi

Rebooting WarGames‘ WOPR With A Pi And Gemini

July 30, 2025 by 4 Comments

WarGames fans, rejoice: [Nick Bild] has rebooted WOPR for real. In his latest hack, the Falcon, he recreates the iconic AI from the 1983 film using a Raspberry Pi 400, a vintage SP0256-AL2 speech chip from General Instrument, and Google’s Gemini LLM. A build to bring us back to the Reagan-era.

Where most stop at visual homage, this one simulates true interaction. The Python script acts as dungeon master for Gemini 2.5 Flash, guiding it to roleplay as the WOPR computer. Keypress sounds click-clack in synchrony with every input. Gemini replies are filtered into allophones, through GI-Pi, [Nick]’s own Python library. The SP0256 then gives it an eerily authentic robotic voice, straight out of 1983.

[Nick] himself is no unfamiliar name to Hackaday. Back in 2020, he hosted a Hack Chat where he talked us through getting from ideas to prototype builds. He practices what he preaches, since he carried out projects like a breadboard 6502 computer, home-automation controlling AI sunglasses, and more silly inventions, like dazzle-proof glasses.

So… shall we play a game? If you’ve ever longed to chat with an 80s military AI about thermonuclear war or tic-tac-toe without doubting you end the world in a blink, start on this build.

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