Sunday, October 30

A Virtual Glimpse Into The Forest

Taking a stroll through the woods in the midst of autumn is a stunning visual experience. It does, however, require one to live nearby a forest. If you are one of those who does not, [Koen Hufkens] has recently launched the Virtual Forest project — a VR experience  that takes you though a day in a deciduous forest.

First off, you don’t need a VR apparatus to view the scenery. Web-browsers and most smart phones are capable of displaying the 360 degree images. The Raspberry Pi 2-controlled Ricoh Theta S camera is enclosed in a glass lamp cover and — with the help of some PVC pipe — mounted on a standard fence post. Power is delivered ingeniously via a Cat5e cable, and a surge protector has also been included in case of lightning strikes.  Depending on when you view the website, you could be confronted with a black screen, or a kaleidoscope of color.

The project’s goal is to track the timing of seasonal changes in North-Eastern forests. If you’re interested in setting up a similar system, the build and a parts breakdown can be found here while the code is available on Github. If the cost of the Theta S camera is prohibitive, then you can make your own panoramic camera to keep your build on track.

[Thanks for the submission, Koen Hufkens!]


Filed under: digital cameras hacks, Raspberry Pi, Virtual Reality

Vintage Radio Transformed into Custom PC Case

We see a lot of old radio restoration projects around here, and we have to admit to having mixed emotions about some of them. It seems a shame to go through the effort to lovingly restore a vintage Art Deco case only to stuff it with a Raspberry Pi and Bluetooth. Seems like if you’re going to restore a radio, go all the way and bring the original electronics back to life. But this radio “restoration” avoids that issue altogether by cleverly concealing a full PC build in a vintage radio case.

u3nwbpdClearly a labor of love, [SolomonZaraa]’s two-year effort guts the radio but still manages to pay homage to the original beauty of the 1939 vintage Philco 39-80 “tombstone” portable AM radio. The first design decision was to retask the original tuning dial as an analog thermometer using an Arduino and a servo. Then a new back was added with an extension for the motherboard and PSU, a drive cage was added, and a surprise slot for the DVD drive was built into the speaker grille. Nice brass trim and a good refinishing of the case resulted in an impressive and unexpected presentation.

You don’t have to go far in the Hackaday Wayback machine to find an antique radio with updated audio, but we’re pretty sure this is the first antique radio PC case mod we’ve seen. Nicely done, [Solomon]!

[via r/DIY]


Filed under: classic hacks, misc hacks

Easy UFO Lights on your Drone for Halloween

Sometimes it’s not so much what you put together, it’s how you use it. The folks at Adafruit have put up a project on how to dress up your drone with ‘UFO lights’ just in time for Halloween. The project is a ring of RGB LEDs and a small microcontroller to give any quadcopter a spinning ‘tractor beam light’ effect. A 3D printed fixture handles attachment. If you’re using a DJI Phantom 4 like they are, you can power everything directly from the drone using a short USB cable, which means hardly any wiring work at all, and no permanent changes of any kind to the aircraft. Otherwise, you’re on your own for providing power but that’s probably well within the capabilities of anyone who messes with add-ons to hobby aircraft.

One thing this project demonstrates is how far things have come with regards to accessibility of parts and tools. A 3D printed fixture, an off-the-shelf RGB LED ring, and a drop-in software library for a small microcontroller makes this an afternoon project. The video (embedded below) also demonstrates how some unfamiliar lights and some darkness goes a long way toward turning the otherwise familiar Phantom quadcopter into a literal Unidentified Flying Object.

While it might be tempting to buzz people to show off the effect on Halloween, flying over or around people with what is essentially an airborne surprise blender is a needless risk. But you don’t need people around; drones (and some cleverness) have opened many doors for the amateur film crowd.


Filed under: led hacks

Saturday, October 29

Build the Simplest Bipolar Power Supply

How many integrated circuits do you need to build up a power supply that’ll convert mains AC into a stable DC voltage? Would you believe, none? We just watched this video by [The Current Source] (embedded below), where he builds exactly that. If you’re in the mood for a very well done review of diode bridges as well as half- and full-wave rectifiers, you should check it out.

First off, [TCS] goes through the basics of rectification, and demonstrates very nicely on the oscilloscope how increasing capacitance on the output smooths out the ripple. (Hint: more is better.) And then it’s off to build. The end result is a very simple unregulated power supply — just a diode bridge with some capacitors on the output — but by using really big capacitors he gets down into the few-millivolt range for ripple into a constant load.

The output voltage of this circuit will depend on the average current drawn, but for basically static loads this circuit should work well enough, and the simplicity of just tossing gigantic capacitors at the problem is alluring. (We would toss in a linear regulator somewhere.)

Quibbling over circuit designs isn’t why you’re watching this video, though. It’s because you want to learn something. Check out the rest of his videos as well. [TCS] has only been at it a little while, but it looks like this is going to be a channel to watch.


Filed under: misc hacks

Living off the Grid, on Water Power

When you think of living off the grid, you often think of solar power. But if you’ve got a good head, and enough flow, water power can provide a much more consistent flow of electrons. All it requires is a little bit of engineering, epic amounts of manual labor, and some tricks of the trade, and you’ll have your own miniature hydroelectric power plant.

[Homo Ludens], the playful ape, has what looks like a fantastic self-sufficient home/cabin in a beautiful part of Chile. His webpages are a tremendous diary of DIY, but the microhydro plant stands out.

You might expect that building a hydro plant involves a lot of piping, and trenching to lie that pipe in, but the exact extent, documented in many photos, is sobering. At places, the pipe needed to be bent, and [Homo Ludens] built a wire-mesh pipe heater to facilitate the work — with the help of a few friends to weigh the pipe down at either end and create the bend. The self-wound power transformer is also a beauty.

There’s a lot more detail here than we can possibly get into, so go check it out. And if you’re in the mood for more hydro, we’ve recently run a writeup of a less ambitious, but still tidy, project that you should see. Or you could just rip apart an old washing machine.

Thanks [Patrick] for the great tip!


Filed under: green hacks

Diamonds are for Data Storage

Most data storage devices we currently use are, at their core, two-dimensional. Sure, a hard drive might have multiple platters, but the data storage takes place on a flat surface. Even an optical drive is effectively a single surface that holds data. At the  City College of New York, they are experimenting with storing data in three dimensions using lab-grown diamonds and LASERs.

Usually, diamonds that have few flaws are more valuable. But in this application, the researchers exploit the flaws to store information. Optical memory that uses a volume instead of a surface isn’t exactly new. However, it is difficult to use these techniques in a way that is rewritable.

Diamonds are a crystalline structure of carbon atoms. Sometimes, though, a carbon atom is missing from the structure. That’s a vacancy. Another defect is when a nitrogen atom replaces a carbon atom. Sometimes a vacancy occurs next to a rogue nitrogen atom and that causes an NV (nitrogen vacancy) center.

It turns out these NV centers are exploitable in several ways ranging from magnetic resonance detection to quantum mechanics experiments. The NV centers can trap an electron, but can also be forced to release a trapped electron. This allows you to treat an NV center with or without an electron as a binary one or zero.

A green LASER can inject an electron into an NV center. A red LASER at low power can determine if an electron is present. At higher powers, the red LASER will eject an electron from an NV center if it is present. If the diamond is in total darkness, the memory state will persevere “virtually forever” according to the researchers (we guess diamonds really are forever).

Of course, the LASER beams are larger than the single-atom defects, but the researchers actually use that to their advantage. By controlling the duration of the LASER pulse, a particular number of NV centers can be charged. That allows a single pulse to store or read multiple bits of data. For example, if the volume contained four NV centers, the volume could represent two bits of information. Since the diamonds are created in a lab, the concentration of NV centers is deterministic.

Currently, the device can store data at a density that exceeds a DVD by about 100 times. However, they are working on ways to get even more dense storage.

We’ve seen glass storage before. You have to wonder if this has applications with 3D ICs, as well.

Photo Credit: [Siddharth Dhomkar] and [Jacob Henshaw] CC BY-ND


Filed under: news

From Poop to cat meeples, the most unusual new board games

Welcome to Ars Cardboard, our weekend look at tabletop games. Check out our complete board gaming coverage at cardboard.arstechnica.com.

At the recent Essen board game fair—the hobby's biggest event—we saw 1,000+ new titles. That meant we also saw our fair share of amazing new games. We also saw plenty of titles that were strange, unusual, and/or poop-focused. These are those games.

Don't let anyone tell you that this isn't board gaming's "Golden Age."

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