Author: Zoe Skyforest

3683 Articles

Building A 2-Way Holographic Display

June 18, 2026 by 6 Comments

Holographic displays sound very fancy but you can build various simple types yourself at home. [Julius Makes] whipped up a neat design that shows a different image depending on the position from which you view it. 

Running the show is a Wemos D1 devboard equipped with the ESP8266 microcontroller. It’s hooked up to a pair of OLED displays over I2C. The displays are placed in a 3D printed assembly that aims each one at a beam-splitter cube. This bounces light projected into one face through 90 degrees, and out another face. By leveraging this, it’s possible to aim each display at one face and bounce it out another, such that looking at either side of the beamsplitter cube shows a different image. Since the beamsplitter cube also allows some light to be transmitted directly through as well, the image from each display appears to float in space.

[Julius] notes that this setup is being used in a puzzle box game, while wondering whether there’s any other fun ways to leverage this technique. We’ve seen some other neat holographic displays before, too, like this neat Holochess build.

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An In-Browser Visualizer For GPS Satellites

June 18, 2026 by 9 Comments

Billions of people use GPS on a daily basis, along with the various other satellite navigation systems available today. But few of us spend much time contemplating the fleet of satellites above us that actually makes the system work. [Robert Wolf] has, though, and he’s built a simple visualizer that displays just what those space birds are doing at any given time.

The visualizer runs right in the browser, and displays a cluster of GPS satellites in a 3D view around the Earth. The tool also offers a list of satellites and related data, including signal-to-noise ratio of the received signals from each one, and the ability to play back satellite positions from previous days. The satellite positions are captured from a GPS receiver that [Robert] operates in the UK.

The view isn’t global or complete, since the receiver can only see a certain number of satellites from its location, but it nevertheless gives an idea of where a subset of GPS satellites are flying above the globe. Depending on the selected view, it’s possible to see the satellites superimposed over the world map itself — or from a distant observer’s perspective, as if looking at the Earth from a distance, among other options.

If you’ve ever wanted an intuitive idea about where the GPS satellites live, this tool is a great way to understand it. We’ve also previously discussed the wide range of GPS alternatives that have been developed over the years. If you’ve got your own GPS hacks brewing in the home lab, don’t hesitate to let us know on the tipsline.

Building And Testing A DIY Robot Actuator

June 17, 2026 by 1 Comment

[Brandon Lai] is hoping to build a humanoid robot. To that end, he’s going to need some actuators, and decided to design his own. His second pass at this turned out pretty well, with a few snags found along the way.

Target specs were a actuator that could run at 40 to 60 RPM while delivering 20 Nm of torque for up to an hour continuously. The design was inspired by an MIT research paper, with [Brandon] making a few mods to suit his use case. Where the MIT design uses an inbuilt planetary gearbox, this build substitutes a cycloidal gearbox with a hope it will provide better torque capacity with less backlash. The design is based around a hand-wound stator made with an off-the-shelf core, while using custom CNC parts and 3D printed components for the motor housing itself.

Testing revealed some limitations. Running off a benchtop power supply with limited current, the motor was only able to achieve 7 Nm of torque, though a better PSU would probably improve this. [Brandon] also noted excessive backlash in the cycloidal gearbox, due to poor tolerances, and the $400 construction cost came in well over budget. Still, [Brandon] hopes to tackle many of these problems in a future revision. CAD files are available online if you’d like to dig deeper into the design.

We’ve featured plenty of great actuator builds over the years.

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Hunting Submarines Via Gravity Is A Tough Errand

May 27, 2026 by 58 Comments

Among so many other technological advances, the Cold War saw the advent of the ballistic missile submarine. The concept was simple—pack enough nuclear warheads to destroy a small civilization into a compact metal tube, and then hide it underwater. The oceans would act as a cloak for your fleet of world-enders, and keep your enemies forever on their toes. A terrifying machine that could both start and end a war with the push of a button.

Most nation states are populated by humans with the will to live. Thus, there has been a great incentive to find ways to keep tabs on these sunken doombringers. Great efforts have gone into improving sonar and magnetic detection methods over the decades, which are the bread and butter of sub hunting to this day. However, military researchers have also explored the prospect of whether submarines could be detected via their effect on the gravitational field alone.

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Remember When Flash Drives Were Going To Make Your PC Faster?

May 26, 2026 by 47 Comments

The 2000s was a decade of great change in the computer industry. The world had grown accustomed to corruptible floppy disks, blue screens of death, and achingly slow load times. In a few short years, all of that would change, as USB drives, better operating systems, and faster processors brought forth a new age of stability and speed.

Amidst this era of upheaval, Microsoft introduced a new technology. It was intended to increase performance on the cheap to a new generation of machines, but it would turn out to be little more than a gimmick that never really caught on. Let’s explore the easily-forgotten legacy of ReadyBoost.

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NoiseCloud: Storing Data On YouTube

May 24, 2026 by 49 Comments

Storage is expensive these days, whether you’re looking at the prices of spinning rust or magic little sticks of silicon. But what if there was some benevolent overlord that you could trick into giving you unlimited storage? That’s where Noisecloud comes in.

Created by [Lucas], Noisecloud is a tool that lets you use YouTube as a form of effectively-unlimited file storage. It works by taking whatever file data you have on hand, and turns it into frames of digital noise that can be stored and transported as an MP4 file and uploaded to YouTube. The encoding process involves first compressing the data with gzip, then packaging it into a high-constrast series of video frames that are then encoded with FFmpeg. Video containers can be produced in various resolutions, all the way down to 640×360 @ 30 fps. There’s also a special “TikTok mode” which is optimised to best preserve data on short form sites that use vertical orientation as default. More commentary from the creator is available via the supporting article on Github.

It’s probably not a practical way to store your files, given the fussy encoding and decoding required to actually use the data. However, it’s an interesting proof of concept that explores how data can be stashed in unexpected places via publicly-accessible services. We’ve explored similar work before, too.

PCB Map Display Keeps An Eye On Family

May 23, 2026 by 21 Comments

PCBs are traditionally designed with traces laid out to support a circuit full of electronic components. However, they’ve become increasingly popular as a way to produce functional visual artworks. This PCB map from [Jonathan] is a great example.

The PCB was designed as a map of the California East Bay area. The roads are laid out as the top-side copper layer, while the land and roads are used for the top solder mask layer, with the flipped land and roads area making up the solder mask on the bottom side. The map data itself was cribbed from Snazzy Maps. Behind the PCB, [Jonathan] mounted a 64 x 32 RGB LED array, which can be seen glowing through from behind the material. The LEDs are controlled by an ESP32, which grabs location data from [Jonathan’s] family member’s mobile devices over MQTT, and uses it to light their positions on the map. Files are on Github for the curious.

If you’ve got a family that is open to location tracking, and the money to pay for a custom PCB, you could probably recreate this project yourself. We’ve seen some other great PCB maps before, too, like this amazing metro tracker. Video after the break.
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