Musical string shooter

Musical String Shooter Makes Sound Visible

April 2, 2017 by 10 Comments

One reason we really like [Rulof]’s hacks is that he combines the most unlikely things to create something unexpected. This time he makes a fast-moving loop of cotton string undulate in time to music.

To do this he uses cotton string, hard drive parts, two wheels from a toy Ferrari, two DC motors, a plastic straw,  a speaker, and an amplifier.  The loop of string sits in the air by being rapidly rotated in between the two wheels. The hard drive parts, driven by the amplifier, give the string a tap with an amplitude, and at a time determined by the music. The result is music made visible in the air in front of you, or in his living room in this case. Check out how he made it, and see it in action in the video below the break.

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VCF: 3D Printing In The 80s

April 2, 2017 by 28 Comments

The Vintage Computer Festival East is going down right now, and I’m surrounded by the height of technology from the 1970s and 80s. Oddly enough, Hackaday frequently covers another technology from the 80s, although you wouldn’t think of it as such. 3D printing was invented in the late 1980s, and since patents are only around for 20 years, this means 3D printing first became popular back in the 2000’s.

In the 1970s, the first personal computers came out of garages. In the early 2000s, the first 3D printers came out of workshops and hackerspaces. These parallels pose an interesting question – is it possible to build a 1980s-era 3D printer controlled by a contemporary computer? That was the focus of a talk from [Ethan Dicks] of the Columbus Idea Foundry this weekend at the Vintage Computer Festival.

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Cordless Water Pump!

April 2, 2017 by 28 Comments

A water pump is one of those items that are uncommonly used, but invaluable when needed. Rarer still are cordless versions that can be deployed at speed. Enter [DIY King 00], who has shared his build of a cordless water pump!

The pump uses an 18 volt brushed motor and is powered by an AEG 18V LiPo battery. That’s the same battery as the rest of [DIY King]’s power tools, making it convenient to use. UPVC pipe was used for the impeller — with a pipe end cap for a housing. A window of plexiglass to view the pump in motion adds a nice touch.

A bit of woodworking resulted in the mount for the pump and battery pack, while a notch on the underside allows the battery to lock into place. Some simple alligator clips on the battery contacts and the motor connected through a switch are all one needs to get this thing running.

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Solar-Powered Prosthetic Skin

April 1, 2017 by 3 Comments

One of the biggest problems for prosthetic users is feel. If you’ve ever tried to hold a pen and write with a numb hand, you’ve realised how important feedback is to the motor control equation. Research is ongoing to find ways to provide feedback from prosthetic limbs, in even a basic format.  The human nervous system is a little more complex than just interfacing with the average serial UART. One of the requirements of many feedback systems is power, which usually would involve bulky batteries or some form of supercapacitors, but a British team has developed a way to embed solar cells in a touch-sensitive prosthetic skin.

The skin relies on everyone’s favourite material of the minute, graphene. A thin layer of graphene allows the prosthetic to feed signals back to the user of both temperature and contact pressure. The trick is that the graphene skin is incredibly transparent, reportedly allowing 98% of light on its surface to pass through. It’s then a simple matter of fitting solar panels beneath this skin, and the energy harvested can then be used to power the sensor system.

The team does admit that some power storage will later be required, as it would be difficult for any prosthetic user if their limbs lost all feedback when they walked into a dark room. The idea of one’s arm losing all feeling upon going to bed isn’t particularly appealing. Check out the paper here (paywalled). Video below the break.
We see a lot of great prosthetic projects cross our desk here at Hackaday – like this 3D printed prosthetic hand. Prosthetics definitely matter, so why not build your own and enter it in the 2017 Hackaday Prize?

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Linear Clock Slows The Fugit Of The Tempus

April 1, 2017 by 11 Comments

We feature a lot of clocks here on Hackaday, and lately most of them seem to be Nixie clocks. Not that there’s anything wrong with that, but every once in a while it’s nice to see something different. And this electromechanical rack and pinion clock is certainly different.

[JON-A-TRON] calls his clock a “perpetual clock,” perhaps in a nod to perpetual calendars. But in our opinion, all clocks are perpetual, so we’ll stick with “linear clock.” Whatever you call it, it’s pretty neat. The hour and minute indicators are laser cut and engraved plywood, each riding on a rack and pinion. Two steppers advance each rack incrementally, so the resolution of the clock is five minutes. [JON-A-TRON] hints that this was a design decision, in part to slow the perceived pace of time, an idea we can get behind. But as a practical matter, it greatly simplified the gear train; it would have taken a horologist like [Chris] at ClickSpring to figure out how to gear this with only one prime mover.

In the end, we really like the look of this clock, and the selection of materials adds to the aesthetic. And if you’re going to do a Nixie clock build, do us a favor and at least make it levitate.

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Cerebrum: Mobile Passwords Lifted Acoustically With NASB

April 1, 2017 by 35 Comments

 

There are innumerable password hacking methods but recent advances in acoustic and accelerometer sensing have opened up the door to side-channel attacks, where passwords or other sensitive data can be extracted from the acoustic properties of the electronics and human interface to the device. A recent and dramatic example includes the hacking of RSA encryption  simply by listening to the frequencies of sound a processor puts out when crunching the numbers.

Now there is a new long-distance hack on the scene. The Cerebrum system represents a recent innovation in side-channel password attacks leveraging acoustic signatures of mobile and other electronic devices to extract password data at stand-off distances.

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Scratchy Brings Digital Clarity To The Vinyl World

April 1, 2017 by 18 Comments

If you walk the halls of audiophilia, you may be aware that there has been a huge amount of work put in to software designed to clean up older audio recordings without compromising the quality of the recording itself. Sometimes the results can be amazing, such as when a stereo image is created from parallel mono recordings made before stereo was even a glint in the eye of a 1930s EMI engineer.

Bob Widlar on analogue versus digital. Original: EDN
[Bob Widlar] on analogue versus digital. Original: EDN.
But what if you are at home, without the benefit of a state-of-the-art studio or high-end digital signal processing? How can you then have pop and crackle free sound from your hi-fi when you put on a piece of vinyl? [Paul Wallace] may just have the answer, he’s made a smartphone app called Scratchy which listens to the output of a turntable, identifies the track being played, and plays the appropriate MP3 file for a digital experience from vinyl. It uses the algorithm published by Shazam to recognize tunes. The software also has a learn mode during which it can be taught about new records in the collection. The app itself is written using the Xamarin framework and has its source code in his GitHup repository, so it’s possible it could be produced for other platforms as well as Android.

Now vinyl purists will be speechless with horror at this wanton desecration of their format while audiophiles will be fuming at the smeary-in-the-midrange MP3s, but we can see its appeal if your vinyl is on the grubby side. It’s fair to say though that the stereo here won’t be sporting it, you’ll tear our analogue signal path from our cold dead hands. Take a look for yourselves, he’s put up a video showing it in operation.

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