The Road To Lucid Dreaming Might Be Paved With VR

March 7, 2025 by Donald Papp 26 Comments

Lucid dreaming is the state of becoming aware one is dreaming while still being within the dream. To what end? That awareness may allow one to influence the dream itself, and the possibilities of that are obvious and compelling enough that plenty of clever and curious people have formed some sort of interest in this direction. Now there are some indications that VR might be a useful tool in helping people achieve lucid dreaming.

The research paper (Virtual reality training of lucid dreaming) is far from laying out a conclusive roadmap, but there’s enough there to make the case that VR is at least worth a look as a serious tool in the quest for lucid dreaming.

One method of using VR in this way hinges on the idea that engaging in immersive VR content can create mild dissociative experiences, and this can help guide and encourage users to perform “reality checks”. VR can help such reality checks become second nature (or at least more familiar and natural), which may help one to become aware of a dream state when it occurs.

Another method uses VR as a way to induce a mental state that is more conducive to lucid dreaming. As mentioned, engaging in immersive VR can induce mild dissociative experiences, so VR slowly guides one into a more receptive state before falling asleep. Since sleeping in VR is absolutely a thing, perhaps an enterprising hacker with a healthy curiosity in lucid dreaming might be inspired to experiment with combining them.

We’ve covered plenty of lucid dreaming hacks over the years and there’s even been serious effort at enabling communication from within a dreaming state. If you ask us, that’s something just begging to be combined with VR.

A Precisely Elegant Cyberdeck Handheld

February 27, 2025 by Donald Papp 15 Comments

[Nicholas LaBonte] shows off a Cyberdeck Handheld that demonstrates just how good something can look when care and attention goes into the design and fabrication. He wanted to make something that blended cyberpunk and nautical aesthetics with a compact and elegant design, and we think he absolutely succeeded.

On the inside is a Raspberry Pi and an RTL-SDR. The back of the unit is machined from hardwood, and sports a bronze heat sink for the Raspberry Pi. The front has a prominent red PSP joystick for mouse input and a custom keyboard. The keyboard is especially interesting. On the inside it’s a custom PCB with tactile switches and a ATmega32U4 running QMK firmware — a popular choice for DIY keyboards — and presents to the host as a regular USB HID device.

The keys are on a single plate of little tabs, one for each key, that sits between the front panel and press on the tact switches inside.

How did he make those slick-looking keys? It’s actually a single plate that sits between the front panel and the switches themselves. [Nicholas] used a sheet of polymer with a faux-aluminum look to it and machined it down, leaving metal-looking keys with engraved symbols as tabs in a single panel. It looks really good, although [Nicholas] already has some ideas about improving it.

On the right side is the power button and charging port, and astute readers may spot that the power button is where a double-stack of USB ports would normally be on a Raspberry Pi 5. [Nicholas] removed the physical connectors, saving some space and connecting the USB ports internally to the keyboard and SDR.

As mentioned, [Nicholas] is already full of ideas for improvements. The bronze heat sink isn’t as effective as he’d like, the SDR could use some extra shielding, and the sounds the keyboard ends up making could use some work. Believe it or not, there’s still room to spare inside the unit and he’d maybe like to figure out a way to add a camera, GPS receiver, or maybe a 4G modem. We can’t wait! Get a good look for yourself in the video, embedded below.

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New Camera Does Realtime Holographic Capture, No Coherent Light Required

February 26, 2025 by Donald Papp 31 Comments

Holography is about capturing 3D data from a scene, and being able to reconstruct that scene — preferably in high fidelity. Holography is not a new idea, but engaging in it is not exactly a point-and-shoot affair. One needs coherent light for a start, and it generally only gets touchier from there. But now researchers describe a new kind of holographic camera that can capture a scene better and faster than ever. How much better? The camera goes from scene capture to reconstructed output in under 30 milliseconds, and does it using plain old incoherent light.

The camera and liquid lens is tiny. Together with the computation back end, they can make a holographic capture of a scene in under 30 milliseconds.

The new camera is a two-part affair: acquisition, and calculation. Acquisition consists of a camera with a custom electrically-driven liquid lens design that captures a focal stack of a scene within 15 ms. The back end is a deep learning neural network system (FS-Net) which accepts the camera data and computes a high-fidelity RGB hologram of the scene in about 13 ms. How good are the results? They beat other methods, and reconstruction of the scene using the data looks really, really good.

One might wonder what makes this different from, say, a 3D scene captured by a stereoscopic camera, or with an RGB depth camera (like the now-discontinued Intel RealSense). Those methods capture 2D imagery from a single perspective, combined with depth data to give an understanding of a scene’s physical layout.

Holography by contrast captures a scene’s wavefront information, which is to say it captures not just where light is coming from, but how it bends and interferes. This information can be used to optically reconstruct a scene in a way data from other sources cannot; for example allowing one to shift perspective and focus.

Being able to capture holographic data in such a way significantly lowers the bar for development and experimentation in holography — something that’s traditionally been tricky to pull off for the home gamer.

DIY Open-Source Star Tracker Gets You Those Great Night Shots

February 25, 2025 by Donald Papp 15 Comments

What does one do when frustrated at the lack of affordable, open source portable trackers? If you’re [OG-star-tech], you design your own and give it modular features that rival commercial offerings while you’re at it.

What’s a star tracker? It’s a method of determining position based on visible stars, but when it comes to astrophotography the term refers to a sort of hardware-assisted camera holder that helps one capture stable long-exposure images. This is done by moving the camera in such a way as to cancel out the effects of the Earth’s rotation. The result is long-exposure photographs without the stars smearing themselves across the image.

Interested? Learn more about the design by casting an eye over the bill of materials at the GitHub repository, browsing the 3D-printable parts, and maybe check out the assembly guide. If you like what you see, [OG-star-tech] says you should be able to build your own very affordably if you don’t mind 3D printing parts in ASA or ABS. Prefer to buy a kit or an assembled unit? [OG-star-tech] offers them for sale.

Frustration with commercial offerings (or lack thereof) is a powerful motive to design something or contribute to an existing project, and if it leads to more people enjoying taking photos of the night sky and all the wonderful things in it, so much the better.

Taking Cues From A Gramophone To Make A Better Marble Music Machine

February 25, 2025 by Donald Papp 13 Comments

[Martin] of [Wintergatan] is on a quest to create the ultimate human-powered, modern marble music machine. His fearless mechanical exploration and engineering work, combined with considerable musical talent, has been an ongoing delight as he continually refines his designs. We’d like to highlight this older video in which he demonstrates how to dynamically regulate the speed of a human-cranked music machine by taking inspiration from gramophones: he uses a flyball governor (or centrifugal governor).

The faster the shaft turns, the harder the disk brake is applied.

These devices are a type of mechanical feedback system that was invented back in the 17th century but really took off once applied to steam engines. Here’s how they work: weights are connected to a shaft with a hinged assembly. The faster the shaft spins, the more the weights move outward due to centrifugal force. This movement is used to trigger some regulatory action, creating a feedback loop. In a steam engine, the regulator adjusts a valve which keeps the engine within a certain speed range. In a gramophone it works a wee bit differently, and this is the system [Wintergatan] uses.

To help keep the speed of his music machine within a certain narrow range, instead of turning a valve the flyball governor moves a large disk brake. The faster the shaft spins, the harder the brake is applied. Watch it in action in the video (embedded below) which shows [Wintergatan]’s prototype, demonstrating how effective it is.

[Wintergatan]’s marble machine started out great and has only gotten better over the years, with [Martin] tirelessly documenting his improvements on everything. After all, when every note is the product of multiple physical processes that must synchronize flawlessly, it makes sense to spend time doing things like designing the best method of dropping balls.

One final note: if you are the type of person to find yourself interested and engaged by these sorts of systems and their relation to obtaining better results and tighter tolerances, we have a great book recommendation for you.

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Infill Injection Experiment Makes Stronger Parts

February 25, 2025 by Donald Papp 28 Comments

[JanTec Engineering] was fascinated by the idea of using a 3D printer’s hot end to inject voids and channels in the infill with molten plastic, leading to stronger prints without the need to insert hardware or anything else. Inspiration came from two similar ideas: z-pinning which creates hollow vertical channels that act as reinforcements when filled with molten plastic by the hot end, and VoxelFill (patented by AIM3D) which does the same, but with cavities that are not uniform for better strength in different directions. Craving details? You can read the paper on z-pinning, and watch VoxelFill in (simulated) action or browse the VoxelFill patent.

With a prominent disclaimer that his independent experiments are not a copy of VoxelFill nor are they performing or implying patent infringement, [JanTec] goes on to use a lot of custom G-code (and suffers many messy failures) to perform some experiments and share what he learned.

Using an airbrush nozzle as a nozzle extension gains about 4 mm of extra reach.

One big finding is that one can’t simply have an empty cylinder inside the print and expect to fill it all up in one go. Molten plastic begins to cool immediately after leaving a 3D printer’s nozzle, and won’t make it very far down a deep hole before it cools and hardens. One needs to fill a cavity periodically rather than all in one go. And it’s better to fill it from the bottom-up rather than from the top-down.

He got better performance by modifying his 3D printer’s hot end with an airbrush nozzle, which gave about 4 mm of extra length to work with. This extra long nozzle could reach down further into cavities, and fill them from the bottom-up for better results. Performing the infill injection at higher temperatures helped fill the cavities more fully, as well.

Another thing learned is that dumping a lot of molten plastic into a 3D print risks deforming the print because the injected infill brings a lot of heat with it. This can be mitigated by printing the object with more perimeters and a denser infill so that there’s more mass to deal with the added heat, but it’s still a bit of a trouble point.

[JanTec] put his testing hardware to use and found that parts with infill injection were noticeably more impact resistant than without. But when it came to stiffness, an infill injected part resisted bending only a little better than a part without, probably because the test part is very short and the filled cavities can’t really shine in that configuration.

These are just preliminary results, but got him thinking there are maybe there are possibilities with injecting materials other than the one being used to print the object itself. Would a part resist bending more if it were infill injected with carbon-fibre filament? We hope he does some follow-up experiments; we’d love to see the results.

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Homebrew CPU Gets A Beautiful Rotating Cube Demo

February 19, 2025 by Donald Papp 10 Comments

[James Sharman] designed and built his own 8-bit computer from scratch using TTL logic chips, including a VGA adapter, and you can watch it run a glorious rotating cube demo in the video below.

The rotating cube is the product of roughly 3,500 lines of custom assembly code and looks fantastic, running at 30 frames per second with shading effects from multiple light sources. Great results considering the computing power of his system is roughly on par with vintage 8-bit home computers, and the graphics capabilities are limited. [James]’s computer uses a tile map instead of a frame buffer, so getting 3D content rendered was a challenge.

The video is about 20 seconds of demo followed by a detailed technical discussion on how exactly one implements everything required for a 3D cube, from basic math to optimization. If a deep dive into that sort of thing is up your alley, give it a watch!

We’ve featured [James]’ fascinating work on his homebrew computer before. Here’s more detail on his custom VGA adapter, and his best shot at making it (kinda) run DOOM.

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