Building A Desk Display For Time And Weather Data

October 2, 2025 by 12 Comments

Just about every laptop, desktop, and smartphone in your life can tell you the date, time, and current weather predictions. However, sometimes it’s nice to have simple data displayed on a bespoke device. That’s what inspired [Mario] to create ESPTimeCast. 

As you might have guessed by the name, the project is designed around the ESP32 and ESP8266 microcontrollers; either one is up to the task of running the show here. Both come with Wi-Fi connectivity out of the box, which makes it easy for them to hook up to the Internet to query NTP servers for the time and weather data from OpenWeatherMap. The data is then displayed on an LED matrix display, made up of four 8×8 LED modules and driven with the aid of the MAX7219 IC. Configuration is handled over a simple web interface hosted on the device itself. All the parts are wrapped up in a 3D-printed housing that would be very fitting in any home that appreciates the magic of late 60s/early 70s decor.

Hackers love building clocks, weather stations, and other useful information displays. We’ve seen a great many examples over the years. If you’re cooking up your own neat project in this area, don’t hesitate to let us know!

Building A Functional Aliens Motion Tracker

October 2, 2025 by 5 Comments

Aliens is the second film from the legendary science-fiction series about, well… aliens. Naturally, it featured some compelling future-tech — such as the M314 Motion Tracker. [RobSmithDev] wanted to recreate the device himself, using modern technology to replicate the functionality as closely as possible.

While a lot of cosmetic replicas exist in the world, [Rob] wanted to make the thing work for real. To that end, he grabbed the DreamHAT+ Radar HAT for the Raspberry Pi. It’s a short-range radar module, and thus is useless for equipping your own air force or building surface-to-air weaponry. However, it can detect motion in a range of a few meters or so, using its 60 GHz transmitter and three receivers all baked into the one chip.

[Rob] does a great job of explaining how the radar works, and how he integrated it into a viable handheld motion tracker that works very similarly to the one in the movie. It may not exactly keep you safe from alien predators, but it’s always fun to see a functional prop rather than one that just looks good.

This isn’t the first time we’ve seen somebody try to replicate this particular prop, but the modern electronics used in this build definitely bring it to the next level.

Continue reading “Building A Functional Aliens Motion Tracker” →

How Hydraulic Ram Pumps Push Water Uphill With No External Power Input

October 2, 2025 by 26 Comments

Imagine you have a natural stream running through a low-lying area on your farm. It’s a great source of fresh water, only you really need it to irrigate some crops sitting at a higher elevation. The area is quite remote from fixed utilities, complicating the problem.

Your first thought might be to grab a commercial off-the-shelf pump of some sort, along with a fancy solar power system to provide the necessary power to run it. But what if there were a type of pump that could do the job with no external power input at all? Enter the hydraulic ram pump.

Continue reading “How Hydraulic Ram Pumps Push Water Uphill With No External Power Input” →

Sending TOSLINK Wirelessly With Lasers

October 2, 2025 by 29 Comments

TOSLINK was developed in the early 1980s as a simple interface for sending digital audio over fiber optic cables, and  despite its age, is still featured on plenty of modern home entertainment devices. As demonstrated by [DIY Perks], this old tech can even be taught some new tricks — namely, transmitting surround sound wirelessly.

Often, a TOSLINK stream is transmitted with a simple LED. [DIY Perks] realized that the TOSLINK signal could instead be used to modulate a cheap red laser diode. This would allow the audio signal to be sent wirelessly through the open air for quite some distance, assuming you could accurately aim it at a TOSLINK receiver. The first test was successful, with the aid of a nifty trick, [DIY Perks] filled the open TOSLINK port with a translucent plastic diffuser to make a larger target to aim at.

The rest of the video demonstrates how this technique can be used for surround sound transmission without cables. [DIY Perks] whipped up a series of 3D printed ceiling mirror mounts that could tidily bounce laser light for each surround channel to each individual satellite speaker.

It’s a very innovative way to do surround sound. It’s not a complete solution to wiring issues—you still need a way to power each speaker. Ultimately, though, it’s a super cool way to run your home theater setup that will surely be a talking point when your guests notice the laser mirrors on the ceiling.

We’ve seen some other stealthy surround sound setups before, too.

Continue reading “Sending TOSLINK Wirelessly With Lasers” →

On 3D Scanners And Giving Kinects A New Purpose In Life

October 2, 2025 by 26 Comments

The concept of a 3D scanner can seem rather simple in theory: simply point a camera at the physical object you wish to scan in, rotate around the object to capture all angles and stitch it together into a 3D model along with textures created from the same photos. This photogrammetry application is definitely viable, but also limited in the sense that you’re relying on inferring three-dimensional parameters from a set of 2D images and rely on suitable lighting.

To get more detailed depth information from a scene you’d need to perform direct measurements, which can be done physically or through e.g. time-of-flight (ToF) measurements. Since contact-free ways of measurements tend to be often preferred, ToF makes a lot of sense, but comes with the disadvantage of measuring of only a single spot at a time. When the target is actively moving, you can fall back on photogrammetry or use an approach called structured-light (SL) scanning.

SL is what consumer electronics like the Microsoft Kinect popularized, using the combination of a visible and near-infrared (NIR) camera to record a pattern projected onto the subject, which is similar to how e.g. face-based login systems like Apple’s Face ID work. Considering how often Kinects have been used for generic purpose 3D scanners, this raises many questions regarding today’s crop of consumer 3D scanners, such as whether they’re all just basically Kinect-clones.

Continue reading “On 3D Scanners And Giving Kinects A New Purpose In Life” →

The Internet We Didn’t Get

October 2, 2025 by 13 Comments

Collective human consciousness is full of imagined or mythical dream-like utopias, hidden away behind mountains, across or under oceans, hidden in mist, or deep in the jungle. From Atlantis, Avalon, El Dorado, and Shangri-La, we have not stopped imagining these secret, fantastical places. One of these, Xanadu, is actually a real place but has been embellished over the years into a place of legend and myth, and thus became the namesake of an Internet we never got to see like all of those other mystical, hidden places.

The Xanadu project got its start in the 1960s at around the same time the mouse and what we might recognize as a modern computer user interface were created. At its core was hypertext with the ability to link not just other pages but references and files together into one network. It also had version control, rights management, bi-directional links, and a number of additional features that would be revolutionary even today. Another core feature was transclusion, a method for making sure that original authors were compensated when their work was linked. However, Xanadu was hampered by a number of issues including lack of funding, infighting among the project’s contributors, and the development of an almost cult-like devotion to the vision, not unlike some of today’s hype around generative AI. Surprisingly, despite these faults, the project received significant funding from Autodesk, but even with this support the project ultimately failed.

Instead of this robust, bi-directional web imagined as early as the 1960s, the Internet we know of today is the much simpler World Wide Web which has many features of Xanadu we recognize. Not only is it less complex to implement, it famously received institutional backing from CERN immediately rather than stagnating for decades. The article linked above contains a tremendous amount of detail around this story that’s worth checking out. For all its faults and lack of success, though, Xanadu is a interesting image of what the future of the past could have been like if just a few things had shaken out differently, and it will instead remain a mythical place like so many others.

3D Print Smoothing, With Lasers

October 2, 2025 by 7 Comments

As anyone who has used an FDM printer can tell you, it’s certainly not the magical replicator it’s often made out to be. The limitations of the platform are numerous — ranging from anisotropic material characteristics to visual imperfections in the parts. In an attempt to reduce the visual artifacts in 3D prints, [TenTech] affixed a small diode laser on a 3D printer.

Getting the 1.5 watt diode laser onto the printer was a simple matter of a bracket and attaching it to the control board as a fan. Tuning the actual application of the laser proved a little more challenging. While the layer lines did get smoothed, it also discolored the pink filament making the results somewhat unusable. Darker colored filaments seem to not have this issue and a dark blue is used for the rest of the video.

A half smoothed half unprocessed test printThe smoothing process begins at the end of a 3D print and uses non-planar printer movements to keep the laser at an ideal focusing distance. The results proved rather effective, giving a noticeably smoother and shiner quality than an unprocessed print. The smoothing works incredibly well on fine geometry which would be difficult or impossible to smooth out via traditional mechanical means. Some detail was lost with sharp corners getting rounded, but not nearly as much as [TenTech] feared.

For a final test, [TenTech] made two candle molds, one smoothed and one processed. The quality difference between the two resulting candles was minimal, with the smoothed one being perhaps even a little worse. However, a large amount of wax leaked into the 3D print infill in the unprocessed mold, with the processed mold showing no signs of leaking.

If you are looking for a bit safer of a 3D print post-processing technique, make sure to check out [Donal Papp]’s UV resin smoothing experiments!

Continue reading “3D Print Smoothing, With Lasers” →