Building A Functional Aliens Motion Tracker

October 2, 2025 by Lewin Day 6 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 Lewin Day 33 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 Lewin Day 30 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” →

Electric Surfboard Gets Thrust Vectoring Upgrade

October 1, 2025 by Lewin Day 1 Comment

The internet has already taught us that an electric surfboard is a great way to get around on the water while looking like an absolute badass. [RCLifeOn] is continuing to push the boat forward in this regard, however, adding thrust vectoring technology to his already-impressive build.

If you’re unfamiliar with the world of electric surfboards, the concept is relatively simple. Stick one or more electric ducted fan thrusters on the back, add some speed controllers, and power everything from a chunky bank of lithium-ion batteries. Throw in a wireless hand controller, and you’ve got one heck of a personal watercraft.

Traditionally, these craft are steered simply by leaning and twisting as a surfer would with a traditional board. However, more dynamic control is possible if you add a way to aim the thrust coming from the propulsion system. [RCLifeOn] achieved this by adding steerable nozzles behind the ducted fan thrusters, controlled with big hobby servos to handle the forces involved. The result is a more controllable electric surfboard that can seriously carve through the turns. Plus, it’s now effectively an RC boat all on its own, as it no longer needs a rider on board to steer.

We’ve covered various developments in this surfboard’s history before, too. Video after the break. Continue reading “Electric Surfboard Gets Thrust Vectoring Upgrade” →

Building An Open Source Point Of Sale System

October 1, 2025 by Lewin Day 21 Comments

[Mukesh Sankhla] has been tinkering in the world of Point of Sale systems of late. His latest creation is a simple, straightforward kiosk system, and he’s open sourced the design.

The Latte Panda MU single-board computer is at the heart of the build, handling primary duties and communicating with the outside world. It’s hooked up to a touchscreen display which shows the various items available for purchase. As an x86 system, the Latte Panda runs Windows 11, along with a simple kiosk software package written in Python. The software uses Google Firebase as a database backend. There’s also an Xiao ESP32 S3 microcontroller in the mix, serving as an interface between the Latte Panda and the thermal printer which is charged with printing receipts.

It’s worth noting that this is just a point-of-sale system; it executes orders, but doesn’t directly deliver or vend anything. With that said, since it’s all open-source, there’s nothing stopping you from upgrading this project further.

We’ve featured other interesting point-of-sale systems before; particularly interesting was the San Francisco restaurant that was completely automated with no human interaction involved Continue reading “Building An Open Source Point Of Sale System” →

The Hottest Spark Plugs Were Actually Radioactive

October 1, 2025 by Lewin Day 57 Comments

In the middle of the 20th century, the atom was all the rage. Radiation was the shiny new solution to everything while being similarly poorly understood by the general public and a great deal of those working with it.

Against this backdrop, Firestone Tire and Rubber Company decided to sprinkle some radioactive magic into spark plugs. There was some science behind the silliness, but it turns out there are a number of good reasons we’re not using nuke plugs under the hood of cars to this day.

Continue reading “The Hottest Spark Plugs Were Actually Radioactive” →

An FPGA-Based Mechanical Keyboard

October 1, 2025 by Lewin Day 16 Comments

You can buy all kinds of keyboards these days, from basic big-brand stuff to obscure mechanical delicacies from small-time builders. Or, you can go the maker route, and build your own. That’s precisely what [Lambert Sartory] did with their Clavier build.

This build goes a bit of a different route to many other DIY keyboards out there, in that [Lambert] was keen to build it around an FPGA instead of an off-the-shelf microcontroller. To that end, the entire USB HID stack was implemented in VHDL on a Lattice ECP5 chip. It was a heavy-duty way to go, but it makes the keyboard quite unique compared to those that just rely on existing HID libraries to do the job. This onboard hardware also allowed [Lambert] to include JTAG, SPI, I2C, and UART interfaces right on the keyboard, as well as a USB hub for good measure.

As for the mechanical design, it’s a full-size 105-key ISO keyboard with one bonus key for good measure. That’s the coffee key, which either locks the attached computer when you’re going for a break, or resets the FPGA with a long press just in case it’s necessary. It’s built with Cherry MX compatible switches, has N-key rollover capability, and a mighty 1000 Hz polling rate. If you can exceed that by hand, you’re some sort of superhuman.

The great thing about building your own keyboard is you can put in whatever features you desire. If you’re whipping up your own neat interface devices, don’t hesitate to let us know!