Year: 2018

Morse Code Blinking Jewelry

May 6, 2018 by 13 Comments

With the size of electronic parts and batteries these days, very small items are obviously becoming more and more viable. [Yann Guidon] has made some awesome pieces of LED jewelry using a minimal number of surface mount parts and a small lithium-ion battery. To make the jewelry stand out a bit, other than just blinking on and off, these LEDs blink a short message in Morse code.

This is an update and open sourcing of some work that [Yann] did a few years ago, and the iterations have resulted in a smaller design. But the main part of the latest version is the addition of the Morse code blinking using a small microcontroller. The microcontroller [Yann] used is the SMD version of the PIC10F200, a small, 8 pin PIC microcontroller. This, a resistor and a metal clip are soldered to pads on a Luxeon Star LED.  The LEDs are undervolted so they’re not too bright, so the heat sink isn’t really needed, but it’s a good size for the components. Because the LEDs don’t generation much heat, the back of the aluminum frame that the LED is on is carved out a bit so that the small lithium-ion battery can go there.

The final component is the code itself, and [Yann] has released it as an assembly file. An associated text file contains the text of the message that you want the earrings to blink. The text file can contain up to 190 bytes. A shell script converts the text to a file that can be included in the asm file. After that script is run, assemble the code and flash it to the PIC and you’re done!

We’ve seen a couple of other LED jewelry projects done, including this LED engagement ring, and these tiny light-up earrings. You can see video of [Yann]’s project in the video below:
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Hurricane Simulator Buoys Research

May 6, 2018 by 1 Comment

They say an ounce of prevention is worth a pound of cure. In this case, 38,000 gallons of seawater is worth an un-quantifiable amount of knowledge about hurricanes. At the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, [Brian Haus] and his colleagues study hurricanes using a simulator–an enclosed glass tank about the size of a lap-swimming pool. With the flip of a switch, a 1700 hp fan can create winds up to 200 miles per hour—stronger than a baseline category 5 hurricane.

Although there’s currently no cure for hurricanes, understanding how they work goes a long way in forecasting their intensity. Scientists know that hurricanes are fueled by the ocean’s warmth, but there’s still plenty of mystery to them. By studying what happens where the wind meets the water, they think they’ll figure out how surface factors like sea spray and bubbles affect a storm’s intensity and drag coefficient. Surf the break to catch the wave tank in action.

Until there’s a cure for hurricanes, we’ll just have to live with them and engineer our structures to withstand them.

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A Home Network, Security System, And A Hidden Room Behind A Bookcase

May 6, 2018 by 33 Comments

Ok, now this is something special. This is a home network and security system that would make just about anyone stop, and with jaw hanging agape, stare, impressed at the “several months of effort” it took [timekillerjay] to install their dream setup. Just. Wow.

Want a brief rundown of the diverse skill set needed to pull this off? Networking, home security, home automation, woodworking, running two thousand feet(!) of cat 6a cable, a fair hand at drywall work for the dozens upon dozens of patches, painting, staining, and — while not a skill, but is definitely necessary — an amazingly patient family.

Ten POE security cameras monitor the premises with audio recording, infrared, and motion detection capabilities. This is on top of magnetic sensors for five doors, and eleven windows that feed back to an ELK M1-Gold security system which effortlessly  coordinates with an Insteon ISY994i smart home hub; this allows for automatic events — such as turning on lights after dark when a door is opened — to occur as [timekillerjay]’s family moves about their home. The ELK also allows [timekillerjay] to control other things around the house — namely the sprinkler system — via relays. [timekillerjay] says he lost track of how many smart switches are scattered throughout his home, but there are definitely 39 network drops that service the premises.

All of the crucial components are hidden in his office, behind a custom bookshelf. Building it required a few clever tricks to disguise the bookshelf for the secret door that it is, as well as selecting components with attention to how much noise they generate — what’s the point of a hidden security system if it sounds like a bunch of industrial fans?

An uninterruptible power supply will keep the entire system running for about 45 minutes if there is a power outage, with the cameras recording and system logging everything all the while. Not trusting the entrance to his vault to something from Batman, he’s also fitted the bookshelf with a 600lb magnetic lock that engages when the system is armed and the door already closed. A second UPS will keep the door secured for 6+ hours if the house loses power. Needless to say, we think this house is well secured.

[Via /r/DIY]

Ham Reviews MiniVNA

May 6, 2018 by 19 Comments

[KB9RLW] wanted to build a vector network analyzer (VNA), but then realized he could buy a ready-made one without nearly the cost it would have been only a few years ago. The network in this case, by the way, is an electrical network, not a computer network. You can use a VNA to characterize components, circuits, antennas, and even feed lines at different frequencies. The miniVNA Pro is economical and can exercise circuits from 1 MHz to 3 GHz. You can see the review in the video below.

There are a few ways to actually create a VNA, but in concept, it is a sweep generator, a detector, and a means to plot the response at each frequency in the sweep. So you’d expect, for example, a resonant frequency to show a peak at resonance and a band reject filter to show a low point.

One of the things interesting about the device is that it uses Java software. That means it doesn’t care much what platform you want to use. The software can show two different plots at once, so [Kevin] hooks it to his 20 meter antenna and shows how it can plot the SWR and impedance around the frequency of interest.

The instrument can be USB powered with the same cable you use to connect the PC. However, it also has an internal rechargeable battery. That battery charges on USB and can operate the device with Bluetooth. We can imagine that being handy when you want to climb up a tower and connect it directly to an antenna as long as you stay in Bluetooth range of the PC. There’s also a phone app, so you can go that route, if you prefer and [Kevin] shows the device working with Android. Of course, you could probably rig a Raspberry Pi on your belt and then use WiFi to let someone on the ground remote desktop in to run measurements. A lot of possibilities.

If you want to roll your own, that’s possible, of course. If you want to get by a bit cheaper, there are less expensive options.

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Glow In The Dark Globe On A Spherical Screen

May 6, 2018 by 18 Comments

Terrestrial globes are almost a thing of the past in an era of Google Earth, but they can still be an exciting object worth hacking together, as [Ivan Miranda] shows with his glow-in-the-dark globe. It’s a globe, it’s a display, and it’s a great use of glow in the dark filament.

For the mechanical part of this build, [Miranda] used glow in the dark filament to 3D print a sphere and a reinforcing ring that hides inside. A threaded rod through the middle secured with screws and bearings make an appropriate spindle, and is attached to a stepper motor in the 3D printed stand. So far, it’s a sphere made of glowey plastic. Where’s the ‘globe’ part coming from?

To project a globe onto this sphere, [Miranda] used a strip of WS2812B LEDs stuck to the inside of the stand’s arc are programmed to selectively illuminate the globe as it rotates on its axis. After a brief hiccup with getting the proper power supply, he was ready to test out his new….. giant light ball.

It turns out, the filament was a bit more transparent than he was expecting so he had to pull it all apart and cover the interior with aluminium tape. [Miranda] also took the chance to clean up the wiring, code, and upgrade to a Teensy 3.1 before another test.

Despite the resulting continental projection being upside-down, it worked! [Miranda] added a USB cable before he closed it up again in case he wanted to reprogram it and display any number of images down the line.

[Thanks for the tip, olivekrystal!]

Crawling A Dungeon, 64 Pixels At A Time

May 5, 2018 by 7 Comments

The trend in video games is toward not being able to differentiate them from live-action theatrical releases, and games studios are getting hard to tell from movie studios. But quality graphics don’t always translate into quality gameplay, and a lot can be accomplished with minimalist graphics. Turn the clock back a few decades and think about the quarters sucked up by classics like Pac-Man, Space Invaders, and even Pong if you have any doubts about that.

But even Pong had more than 64 pixels to work with, which is why this dungeon-crawler game on an 8×8 RGB matrix is so intriguing. You might think [Stolistic]’s game would be as simple as possible but think again. The video below shows it in action, and while new users will need a little help figuring out what the various colors mean, the game is remarkably engaging. The structure of the dungeon is random with multiple levels to unlock via the contents of power-up chests, and there are mobs to battle in a zoomed-in display. The game runs on an Arduino Uno and the matrix is driven by a bunch of 74HC595 shift registers.

It’s fun to see what can be accomplished with as little as possible. Looking for more low-res goodness? Check out this minimalist animated display, or a Geiger counter with a matrix display.

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Printed Circuits In The Palm Of Your Hand

May 5, 2018 by 11 Comments

If you’ve ever wanted to more fully integrate yourself with technology, you might have to thank a team of researchers — led by [Michael McAlpine] — at the University of Minnesota in the near future. They’ve developed a technique that allows circuits to be printed directly onto your skin, with the team arguing — once the low-cost printer is modified for compact portability — it would be ideal for ‘on-the-fly’ circuit needs.

“But the hand isn’t exactly a stable print bed,” you say. We hear you, and the team is actually one step ahead — the printer can compensate for subtle movements during the printing process by tracking markers placed on the hand. The ‘filament’ is made from silver flakes — akin to conductive ink — which prints and cures at room temperatures, and can be either peeled or washed off. We should hope so, as it’s meant to be layered on human skin.

Speaking of which, it can also print cells!

It’s only been tested on a mouse so far, but the same technology that allows the printer to accurately track the hand means that it could use bio-ink to directly add cells to a wound or some other epidermal affliction to help speed the healing process.

For the circuits, though, you’ll still need the other circuit components and a compact means to power them — to say nothing about the fact that if the circuit is water-soluble, then a little perspiration would cause the ink to run. We’re excited to see where this tech goes!

[Thanks for the tip, Qes!]

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