Forget Radio! Transmitting With Neutrons

November 14, 2021 by 50 Comments

Throughout history, people have devised ways to send information across long distances. For centuries we relied on smoke signals, semaphores, and similar physical devices. Electricity changed everything. First the telegraph and then radio transformed communications. Now researchers at the University of Lancaster have demonstrated another way to send wireless data without using electromagnetic radiation. They’ve harnessed fast neutrons from californium-252 and modulated them with information with 100% success.

The setup was interesting. The radioactive material was encased in a cubic meter steel tank filled with water. A pneumatic system can move the material to one edge of the tank which allows fast neutrons to escape. A scintillating detector can pick up the increased neutron activity. It seems like it is akin to using what hams call CW and college professors call OOK (on off keying). You can do that with just about anything you can detect. A flashlight, knocking on wood, or — we suppose — neutrons.

We wondered what the practical application of this might be. The paper suggests that the technique could send data through metal containment structures like those of a nuclear reactor or, perhaps, a spacecraft where you don’t want anything unnecessarily breaching the containment. After all, neutrons cut through things that would stop a conventional radio wave cold.

It seems like you only have to prove you can detect something to make this work — it really doesn’t matter what it is you are detecting. It seems like it would be much harder to do more advanced types of modulation using neutrons. Maybe this is why we don’t hear aliens. They are all Morse code operators with neutron-based telegraphs.

UV sensing amulet

Tiny Talisman Warns Wearer About UV Exposure

November 14, 2021 by 14 Comments

Given how important our Sun is, our ancestors can be forgiven for seeing it as a god. And even now that we know what it actually is and how it works, it’s not much of a reach to think that the Sun pours forth evil spirits that can visit disease and death on those who bask too long in its rays. So an amulet of protection against the evil UV rays is a totally reasonable project, right?

As is often the case with [mitxela]’s projects, especially the more bedazzled ones, this one is approximately equal parts electronics and fine metalworking. The bulk of the video below focuses on the metalwork, which is pretty fascinating stuff. The case for the amulet was made from brass and sized to fit a CR2032 coin cell. The back of the amulet is threaded to act as a battery cover, and some fancy lathe work was needed there. The case was also electroplated in gold to prevent tarnishing, and lends a nice look when paired up with the black solder mask of the PCB.

On the electronics side, [mitxela] took pains to keep battery drain as low as possible and to make the best use of the available space, choosing an ATtiny84 to support a TTP223 capacitive sensing chip and a VEML6075 UV sensor. The touch sensor allows the wearer to wake the amulet and cycles through UV modes, which [mitxela] learned were not exactly what the sensor datasheet said they were. This required a few software hacks, but in the end, the amulet does a decent job of reporting the UV index and looks fantastic while doing it.

Continue reading “Tiny Talisman Warns Wearer About UV Exposure” →

Those Bullet Effects In Terminator 2 Weren’t CGI

November 14, 2021 by 25 Comments

Remember Terminator 2? Guns were nearly useless against the murderous T-1000, played by Robert Patrick. Bullets fired at the “liquid metal” robot resulted only in a chrome-looking bullet splash that momentarily staggered the killing machine. The effects were done by Stan Winston, who died in 2008, but a video and short blurb shared by the Stan Winston School of Character Arts revealed, to our surprise and delight, that the bullet impact effects were not CGI.

How was this accomplished? First of all, Winston and his team researched the correct “look” for the splash impacts by firing projectiles into mud and painstakingly working to duplicate the resulting shapes. These realistic-looking crater sculpts were then cast in some mixture of foam rubber, and given a chromed look by way of vacuum metallizing (also known as vacuum deposition) which is a way of depositing a thin layer of metal onto a surface. Vacuum deposition is similar to electroplating, but the process does not require the object being coated to have a conductive surface.

These foam rubber splash patterns — which look like metal but aren’t — were deployed using a simple mechanical system. A variety of splashes in different sizes get individually compressed into receptacles in a fiberglass chest plate. Covering each is a kind of trapdoor, each held closed by a single pin on a cable.

To trigger a bullet impact effect, a wireless remote control pulls a cable, which pulls its attached pin, and the compressed splash pattern blossoms forth in an instant, bursting through pre-scored fabric in the process. Sadly there are no photos of the device itself, but you can see it in action in the testing video shared by the Stan Winston School, embedded below.

Continue reading “Those Bullet Effects In Terminator 2 Weren’t CGI” →

A robot that uses CV to detect villagers in Stardew Valley and display their gift preferences on a screen.

Stardew Valley Preferences Bot Is A Gift To The Player

November 14, 2021 by 1 Comment

It seems like most narrative games have some kind of drudgery built in. You know, some tedious and repetitious task that you absolutely must do if you want to succeed. In Stardew Valley, that thing is gift giving, which earns you friendship points just like in real life. More important than the giving itself is that each villager has preferences — things they love, like, and hate to receive as gifts. It’s a lot to remember, and most people don’t bother trying and just look it up in the wiki. Well, except for Abigail, who seems to like certain gemstones so much that she must be eating them. She’s hard to forget.

[kutluhan_aktar]’s villager gift preferences bot is a fun and fantastic use of OpenCV. This bot uses a LattePanda Alpha 864s, which is a single-board computer with an Arduino Leonardo built in. It works using template matching, which is basically a game of Where’s Waldo? for computers.

Given a screenshot of each villager in various positions, the LattePanda recognizes them among a given game scene, then does a lookup of their birthday and preferences which the Leonardo prints on a 3.5″ LCD screen. At the same time, it alerts the player with a buzz and big green LED. Be sure to check it out in action after the break.

In Animal Crossing, the drudgery amounts to pressing the A button while catching shooting stars. That’s not a huge problem for a Teensy.

Continue reading “Stardew Valley Preferences Bot Is A Gift To The Player” →

a money shot of the hidden arcade

Arcade Machine Pack And Play

November 14, 2021 by 3 Comments

There’s something about the large imposing wooden box of an arcade machine that lends a confident presence to a room. The problem with a tall and heavy box is that it takes up quite a bit of space and readily draws the eye. So [Alexandre Chappel] set out to avoid that and build an arcade machine that could hide in plain sight.

Extra points awarded for neat wiring on the inside.

The idea is a wooden box hung on the wall that folds up when not in use. [Alex] starts with Baltic birch plywood cut into the panels. Next, he applies edge banding (a thin veneer with some glue on the backside) so that all the exposed edges look like natural wood. Next, a screen hole is routed into the face frame, allowing an LCD monitor to sit snuggly in. A combination of pocket holes and biscuits allows [Alex] to assemble everything with no visible screws or fasteners.

With the help of a 3D printer, he quickly fabricated a locking mechanism to keep the front panel attached when it folds up. The hinge is also 3D printed. The typical Raspberry Pi 4 powers this particular machine. Two french cleats hold the box onto the wall, and once the system is on the wall, we have to say it looks incredible.

If you’re looking for a smaller but more traditional arcade cabinet, why not take a look at this arcade cabinet for toddlers? Or, if you loved the solid wood look of the hidden arcade, this full-sized solid oak cabinet would be something you would enjoy. Video after the break.

Continue reading “Arcade Machine Pack And Play” →

Chipboard prototype of a wireless phone charger with style.

Prototyping Your Way To Better Prototypes

November 13, 2021 by 13 Comments

If you’ve ever made a prototype of something before making the “real” one or even the final prototype, you probably already know that hands-on design time can’t be beat. There’s really no substitute for the insight you will glean from having a three-dimensional thing to hold and turn over in your hands for a full assessment. Sometimes you need to prototype an object more than once before investing time, money, and materials into making the final prototype for presentation.

This is [Eric Strebel]’s second video in series about making an eco-friendly wireless phone charger. He made a paper prototype in the first video, and in this follow-up, he refines the idea further and makes a chipboard version of the charger before the final molded paper pulp prototype. The main advantage of the chipboard version is to design the parts so that each one will be easier to pull from its mold in a single piece without any undercuts.

By building the chipboard version first, [Eric] is able to better understand the manufacturing and assembly needs of this particular widget. This way, he can work out the kinks before spending a bunch of time in CAD to create a 3D-printed mold and making the paper pulp prototype itself. He emphasizes that this process is quite different from the 2.5D method of laser-cutting a single piece of chipboard and folding it up into a 3D object like it was a cereal box, which is likely to hide design issues. Be sure to check out the video after the break.

We think this prototype is quite nice-looking, and believe that everything deserves good design. Why should a wireless charger be any different? [Eric] has prototyped in a lot of media, but he seems especially skilled in the art of foam core board. Start with the masterclass and you’ll have a better appreciation for his foam armored vehicle and one of the many ways he smooths out foam parts.

Continue reading “Prototyping Your Way To Better Prototypes” →

Bluetooth RC Car Packs In A Few Sensors

November 13, 2021 by 4 Comments

Have you ever been walking around the house, desperate to know the ambient temperature, humidity, and barometric pressure? Have you ever wanted to capture that data with a small remote-controlled platform? If so, this project from [TUENHIDIY] will be exactly what you’ve been looking for. 

The little remote-control car is built around a Seeed Wio Terminal. This is a microcontroller platform that comes with a screen already attached, along with wireless hardware baked in and Grove connectors for hooking up external modules. Thus, the car adds a DHT11 temperature and humidity sensor, along with a BMP280 air pressure sensor using the Grove connectors.

Driving the car is done via a Blynk smartphone app that communicates with the Wio Terminal. Small DC motors at each wheel are driven via a DFRobot quad-motor shield. With the built-in screen, the RC car displays commands received from the smartphone app, as well as the temperature, humidity and pressure in the immediate environment.

We really like the simple PVC-based chassis design, and it’s a straightforward project that demonstrates how to build a Bluetooth-controlled car. Data collected by the sensors is also visible on the smartphone app, so if you need to sample conditions in the next room without getting off the couch, you could do that pretty easily.

Projects like these are a good way to get familiar with working with motors and sensors. It’d be a great base for simple robotics development, too. We’ve featured builds from [TUENHIDIY] before, too, like this great rotary plotter that can draw on bottles. Video after the break.

Continue reading “Bluetooth RC Car Packs In A Few Sensors” →