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!

Toy Train Joins The Internet Of Things

September 30, 2025 by Lewin Day 1 Comment

[Zoltan] was developing a workshop on Matter for DEF CON, and wanted to whip up a fun IoT project to go with it. His idea was simple—take a simple toy train, and put it on the Internet of Things.

Speed and low cost were the goals here, with a budget of around $40 and a timeline of one week. The train set sourced for the build was a 43 piece set with a locomotive, one carriage, and a simple oval track, retailing for $25. The toy train got a new brain in the form of an ESP32-C3 DevKitM-1, with the goal of commanding the device over Wi-Fi for ease of use. The microcontroller was set up to control the train’s brushed DC motor with an IRL540 MOSFET. A USB battery bank was initially employed to power the rig, which sat neatly on the train’s solitary carriage. This was later swapped out for a CR123A battery, which did the job for the train’s short duration in service.

Code for the project was simple enough. The ESP32 simply listens for commands via Matter protocol, and turns the train on and off as instructed. [Zoltan] demos the simple interoperability of the Matter protocol by switching the train on and off with Google Home voice commands, and it works perfectly well.

Toy trains aren’t something we typically see included in smart homes, but maybe they should be. If you’re cooking up your own oddball IoT hacks, be sure to let us know on the tipsline!

Hard Hat Becomes Bluetooth Direction Finder

September 30, 2025 by Lewin Day 10 Comments

Have you ever wanted to find a Bluetooth device out in the wild while looking like the comic relief character from a science-fiction series? You might like Dendrite, the direction-finding hat from [SolidStat3].

Dendrite is intended for hunting down Bluetooth devices. It’s capable of direction estimation based on signal strength readings from four ESP32 microcontrollers mounted on an off-the-shelf hard hat. Each ESP32 searches for BLE devices in the immediate area and reports the apparent signal strength to a fifth ESP32, which collates readings from all units. It then runs a simple multilateration algorithm to estimate the direction of the device. This information is then displayed via a ring of addressable LEDs around the perimeter of the hat. White LEDs marking the direction of the detected device. The only problem? You can’t see the LEDs while you’re wearing the hat. You might need a friend to help you… or you can simply take it off to see what it’s doing.

Ultimately, this project is a useful direction-finding hard hat that would also make a perfect prop from an episode of Inspector Spacetime. We’ve covered direction finding in other contexts before, too. Meanwhile, if you’re cooking up your own innovative hard hat (or radio) hacks, don’t hesitate to let us know!