Hackaday Links: August 24, 2025

If you’ve ever opened a “links roundup” intending to spend three minutes and then looked up to discover it’s somehow next Tuesday, you already understand the magic trick.
A good roundup isn’t just a listit’s a curated rabbit-hole sampler. And Hackaday Links: August 24, 2025 is the kind of sampler that makes you laugh, squint, and mutter,
“Okay, fine, I guess I’m learning about hologram cops and onion statistics today.”

This particular edition stitches together five wildly different storiespublic-safety theater tech, café-as-office culture, VR-controlled robot brawls, a slice of radio history,
and an oddly profound math-and-tears exploration of onionsthen tops it off with a musical instrument that appears to have been invented by a time-traveling audio engineer
who got stuck inside a bamboo grove with a reel-to-reel deck.

Why “Hackaday Links” still works in 2025

Hacker culture is sprawling. On any given day, “hardware” can mean a transparent projection screen in a city park, a humanoid robot in a boxing ring,
a shortwave contact with Greenland in 1925, or a data visualization about diced onions (yes, really). The Hackaday Links format embraces that sprawl.
It’s a weekly reminder that the boundary between “serious engineering” and “delightful nonsense” is mostly just a labeling problem.

For SEO people, these roundups are also a quiet masterclass in intent: readers show up for novelty, stay for context, and leave with a list of things to research later.
That’s the dreamhigh dwell time, high satisfaction, low regret (until you realize you now want to build a Pepper’s Ghost rig in your living room).

The August 24, 2025 lineup in one sentence

Theme: the physical world is getting weirdersometimes for safety, sometimes for productivity, sometimes for sport, and sometimes because a musician looked at magnetic tape and thought,
“What if this was a violin, but also… a time machine?”

Highlight 1: The “holographic officer” and the science of looking official

A deterrent you can’t argue with (because it isn’t real)

The first link is about a holographic police officer deployed in a park at nightessentially a projected figure that delivers warnings and announces CCTV monitoring.
The interesting part isn’t just the gadgetry; it’s the psychology. You don’t need a fully autonomous robot cop to change behavior. Sometimes you just need
the perception of enforcement, delivered with enough glow and authority to trigger that ancient human reflex: “Someone is watching; maybe don’t do the dumb thing.”

Technically, a lot of “hologram” installations aren’t true holograms at all. Many rely on variations of Pepper’s Ghostan optical illusion that uses angled transparent material
(glass, acrylic, film) and controlled lighting/projection to create a floating, ghostlike image. It’s a theater trick wearing a modern hoodie.
That’s not a dig; it’s a compliment. Some of the most durable technologies are the ones that work because humans have predictable eyeballs.

What makers can learn from it

• Illusions scale faster than robots. A projection system is easier to deploy than staffing or building a fully capable machine.
• “Good enough” presence can be effective. Deterrence is often about visibility, not physical intervention.
• Ethics still apply. If you amplify surveillance messaging, be honest about what’s actually monitored and how footage is handled.

Highlight 2: Starbucks, “cagongjok,” and the café that became an office park

When the third place turns into the “fourth monitor”

Another link points to a story that sounds like satire but isn’t: some customers in South Korea were reportedly bringing desktop computers and even printers into cafés,
effectively turning tables into mini workstations. Starbucks responded by asking patrons not to bring bulky equipment so stores remain accessible and comfortable for everyone.

This is an oddly perfect 2025 moment: remote work norms meet urban space constraints meet “third place” branding. Laptops? Sure. Tablets? Fine.
But once a printer shows up, you’ve crossed from “coffee shop vibes” into “corporate IT support nightmare.” The café becomes a coworking space without the coworking-space pricing,
and the business has to decide whether it’s a community hangout or a rentable utility.

What’s actually happening beneath the headline

The real story is scarcity: not enough affordable workspace, not enough flexible office supply, and not enough social agreement about what shared spaces are for.
A café seat is simultaneously a revenue engine, a social commons, and (increasingly) someone’s temporary desk. Policies like “no desktop computers” are an attempt to redraw boundaries
without killing the vibe that makes people show up in the first place.

Highlight 3: Robo Fight Club and the rise of VR-controlled humanoid chaos

Human reflexes, robot bodies, real collisions

The roundup also nods to a “Robo Fight Club” concept where humanoid robots fight while controlled by human pilots wearing VR headsets.
It’s part sport, part performance art, part tech demoand 100% the kind of thing that makes safety engineers wake up at 3 a.m. to whisper,
“Did we torque-limit the elbows?”

The most fascinating detail is the interface promise: the pilots aren’t just steering a machine like a forklift. They’re trying to feel like they are the robot.
That’s the same direction high-end robotics research keeps pointing: mapping human intent and motion into complex bodies is powerful, intuitive, and brutally hard.
Balance, latency, overheating, and impact forces all turn “cool idea” into “long weekend in the lab.”

Why this matters beyond entertainment

Put the boxing gloves aside and you’re looking at the same core problem behind disaster-response robots, industrial humanoids, and remote manipulation:
translating human skills into machine actions. Today it’s a punch. Tomorrow it’s turning a valve in a hazardous environment or moving parts in a factory.
The cage is just an attention magnet.

Highlight 4: Arthur Collins and the kind of engineering that built the modern world

Before “wireless” meant earbuds

This Links edition also points to a piece about Arthur Collinsthe radio pioneer associated with what became Collins Radio.
The story is a refreshing reminder that “hacking” didn’t start with microcontrollers. It started with people pushing the limits of what was possible with
components, power, antennas, and stubborn curiosity.

One standout anecdote: a 1925 shortwave contact between Iowa and Greenland (in an era when long-distance radio felt like bending the laws of nature).
From there, the Collins story threads into the growth of radio equipment and the broader communications ecosystem.
It’s the old-school version of a startup origin story: basement builds, incremental improvements, and a community of fellow enthusiasts who trade notes and iterate.

The modern takeaway

If you build anythingRF projects, embedded systems, even “simple” sensorsCollins’ era is a reminder that constraints can be a creative engine.
Limited tooling forces clarity. Limited bandwidth forces efficiency. Limited budget forces reuse. And suddenly you’ve reinvented half of engineering best practice
just trying to make the thing work.

Highlight 5: Onion math, data visualization, and the surprisingly emotional life of dicing

Quantifying a kitchen ritual

Yes, onions made it into Hackaday Links. And honestly? Respect. The featured data story explores onion dicing and proposes a tongue-in-cheek “onion constant,” using measurement
and variability to show how different cutting styles affect the final distribution of pieces.

It’s delightful because it turns a daily task into an experiment you can replicate at home with a cutting board, a ruler, and the willingness to cry for science.
The deeper lesson is that data thinking is portable: you can apply standard deviation and consistency checks to anythingfrom manufacturing tolerances
to meal prep.

And yes, the tears are chemical

Onions release irritant compounds when their cells are broken; your eyes respond by producing tears to flush them out. The practical advice remains boring-but-true:
use a sharp knife (less cell damage), improve ventilation, and chill the onion if you’re particularly sensitive. You can’t fully “outsmart” chemistry,
but you can negotiate with it.

Bonus highlight: Bowing magnetic tape like it’s a folk instrument from the future

Reel-to-reel as a playable surface

The final link is the kind of thing that makes makers grin: musicians using reel-to-reel tape recorders as instruments, including a setup where magnetic tape is stretched
to a bamboo bow and “bowed” to create synth-like sounds. Faster bowing raises pitch; slower bowing lowers it. It’s friction, speed control, and audio playback physics
turned into performance.

This is what hacking looks like outside the lab: repurposing old systems, exposing their “hidden” behaviors, and turning constraints into expression.
It’s also a gentle reminder that obsolete technology doesn’t dieit just waits for someone imaginative enough to give it a second job.

What ties all five links together

On the surface, this roundup is chaotic. Underneath, it’s coherent:

• Perception is a tool. Hologram cops and café policies both shape behavior without brute force.
• Embodiment is coming back. VR-controlled robots and industrial humanoids are about doing, not just computing.
• Old tech still teaches. Collins-era radio and reel-to-reel tape reveal fundamentals we still rely on.
• Measurement is everywhere. Even onion dicing benefits from a little math and curiosity.

Practical takeaways for makers, hackers, and curious professionals

1) Prototype the illusion before the robot

If your goal is deterrence, attention, or messaging, a projection system may outperform an autonomous machine on cost and deployment speed.
Start with optics and human factors, then escalate complexity only when needed.

2) Design for shared spaces (because users will push boundaries)

The “desktop-and-printer in a café” story is a reminder that people optimize for convenience. Your product, space, or system will be used at the edge cases.
Plan policies, constraints, and ergonomics for the weird scenarios, not just the brochure version.

3) Teleoperation is a superpowerbut latency is the villain

VR control of humanoids is thrilling, but it’s only as good as the stability and responsiveness of the system. If you’re building anything remotely operated,
obsess over feedback loops, failure modes, and graceful degradation.

4) Learn from RF history: fundamentals don’t expire

Whether you’re tuning an antenna or optimizing a sensor network, the same truth holds: signal, noise, power, and environment are the real bosses.
The vintage stories are fun, but they’re also textbooks with better anecdotes.

5) Apply “onion thinking” to your builds

Measure outcomes, track variability, and improve consistency. The funniest projects often teach the most transferable skillsbecause they make you actually
run the experiment instead of arguing on the internet about it.

Extra : maker-style experiences inspired by “Hackaday Links: August 24, 2025”

If you want to squeeze real value out of a links roundup, the best move is to treat it like a lab assignmentpick one item and recreate a tiny version of it.
Not a full build, not a months-long obsession (unless you’re into that), just a “weekend-scale” experiment that turns reading into doing.

Start with the hologram officer concept. You don’t need a park or a police uniform to learn the core trick. A basic Pepper’s Ghost demo can be built with a clear
acrylic sheet, a darkened room, and a bright screen (a tablet works). Angle the acrylic around 45 degrees and place the screen out of the audience’s direct line of sight.
Suddenly, you’re not just consuming a headlineyou’re learning about reflections, viewing angles, contrast, and why some “holograms” look incredible in promo videos
and underwhelming in a brightly lit food court.

Next, take the Starbucks “cagongjok” story as a human-systems exercise. Try working from a café for an hour with only what fits in a small baglaptop, charger, maybe a notebook.
Pay attention to what feels fair in a shared space: how long you occupy a table, how you manage noise, and how your setup affects foot traffic and seating.
It becomes obvious why businesses draw lines. The goal isn’t to shame anyone; it’s to notice how quickly personal convenience collides with communal design.

For the robot fight club angle, you can’t (and shouldn’t) recreate metal-on-metal combat in your living room, but you can explore the same control challenges safely.
Use a cheap RC car or a small wheeled robot and pilot it via a camera feed on your phone. Even with a simple platform, you’ll feel the problem immediately:
latency makes you overcorrect, narrow field-of-view makes navigation harder than expected, and “I totally meant to do that” becomes your default explanation.
That’s the lesson behind every teleoperated humanoid dreaminterfaces matter as much as actuators.

Then go retro with Arthur Collins as inspiration. Build (or at least simulate) something RF-adjacent: a simple antenna experiment, a software-defined radio listen session,
or a basic propagation log. The point is to respect the medium. When you notice how environment changes receptiontime of day, interference, placementyou start thinking
like the people who built global communication from scratch. It’s humbling in the best way.

Finally, do the onion experimentbecause it’s funny and it works. Dice one onion with your normal method, then dice another while intentionally controlling variables:
sharpen the knife, chill the onion, and aim for consistent cuts. Compare results. You’ll see variance in piece size, and you’ll probably reduce tears.
That “onion thinking” transfers directly to hardware: control inputs, measure outputs, reduce variability, repeat. And if all else fails, you still end up with dinner.

Bonus credit: if you have any old audio gear, try a harmless tape-loop experiment with a cassette or reel-to-reel (no permanent mods, no heroic disassembly).
The moment you hear how speed and friction change sound, the bowed-tape instrument stops being a weird internet clip and becomes a physics lesson you can hear.
That’s the real payoff of a roundup like thisyour curiosity becomes a tool, not just a mood.

Conclusion

Hackaday Links: August 24, 2025 is a compact snapshot of modern maker culture: public tech that blurs into theater, work culture that spills into retail spaces,
embodied robotics that’s equal parts sport and research, foundational radio history that still informs today’s systems, and playful measurement applied to everyday life.
If you read it like entertainment, it’s fun. If you read it like a prompt list for experiments, it’s fuel.