Making Graphene With A DVD Burner

December 21, 2012 by 64 Comments

A group of researchers have figured out how to produce graphene using a DVD drive. This discovery helps clear the path for mass production of the substance, which was discovered in the late 1980’s. More recently, the 2010 Nobel Prize for Physics was awarded to a team that produced two-dimensional graphene; a substance one just atom thick. One method of doing so used Scotch tape and is mentioned in the video after the break as a technique that works but is not feasible for large-scale production.

The process seen here starts with graphite oxide because it can be suspended in water. This allows a lab technician to evenly distribute the substance on a plastic surface. Note the use of optical discs. The second part of the process involves hitting the dried layer of graphite oxide with a laser. It just so happens that this can be done with a consumer DVD drive. The result is graphene that can be used in circuits and may have potential as a fantastic super-capacitor.

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Wooden Box Repeats Rhythm Used When Knocking On The Lid

December 21, 2012 by 10 Comments

knock-box-build

[Paul Mandel] just finished building this knock box project. It’s a familiar concept that uses a solenoid to tap on the side of the box. The Arduino driven setup monitors vibrations on the lid. When you knock on the box, it records the pattern and plays it back using the solenoid.

He was inspired by a knock-detecting door lock. Using that code as the starting point he implemented a system that takes input from a simple push button and echos back the rhythm using the Pin 13 LED on the Arduino board. This is a great way to start as it removes the complexity of driving a solenoid and monitoring a piezo element. After a bit of success he implemented each of those hardware modules one at a time. You can get a look at the final product in the clip after the break.

One of our favorite version of this project is still the knock block from several years back.

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Raspberry Pi Laptop Is Just A Little Too Big For A Pocket

December 21, 2012 by 30 Comments

Over on the Parts People blog, [Nathan] created his own Raspberry Pi laptop. It’s got all the bells and whistles, including a keyboard, trackpad, battery, and even a 3D printed case.

Of course [Nathan]’s laptop contains a Raspi, but the other included parts are where this palmtop computer is turned into something useful. For powering the Pi and 3.5″ composite LCD, [Nathan] took apart the battery pack from an old Dell laptop. By throwing out the bits of plastic surrounding these rechargeable cells and reusing the battery connector, [Nathan] was able to power the Pi, and all the peripherals for 10 hours.

Also included in [Nathan]’s Raspi palmtop is a 64 GB SSD connected to the powered USB hub. This, along with the 4 GB boot SD card, provides more than enough storage for listening to a music library, or even watching a few TV shows on the 3.5″ screen,

 

Open Source Software Defined Radio Transceiver

December 21, 2012 by 30 Comments

SDR

As the year draws to a close, we must look back and look at the advances in amateur radio this year. The RTL-SDR tuner hack, a USB TV Tuner to create a software defined radio receiver, is one of the greatest hacks of the last 12 months and a great justification for 2012 being the year of software defined radio receivers. 2013 is shaping up to have even more advances in the state of software defined radio. This time we’ll be transmitting as well, possibly with [AE9RB]’s Peaberry SDR transceiver.

The Peaberry SDR transceiver is a kit to both transmit and receive on every HAM band between 160 meters (1.8 MHz) to 17 meters (18 MHz). It does this through a USB interface and a 48kHz, 24-bit interface that is (or will shortly be) compatible with all the major SDR interfaces.

While the Peaberry SDR requires an amateur radio license to operate, we can’t wait to see what else will be coming to the software defined radio scene in the next year.

Thanks [Zach] for sending this one in.

Arduino Compatible Christmas Tree

December 21, 2012 by 9 Comments

tree

It wouldn’t be the holidays without an LED Christmas tree, and luckily [Danilo] brings the goods with an Arduiinofied LED Christmas tree (Italian, translation).

In the past week, we’ve seen LED Christmas trees of digital logic and a great freeform circuit version. Unlike these other builds [Danilo]’s LED tree uses a piece of protoboard masterfully cut into the shape of a Christmas tree. There’s no PCB for this build; just a lot of bare wires and a lot of patience.

Because [Danilo]’s tree makes use of the PWM pins on his Arduino, it was possible to connect his tree to the Arduino with a few 90 degree headers. This provides a great base for his tree and makes it possible to build a professional-looking enclosure for his project.

You can check out [Danilo]’s tree in action after the break.

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3D Printing Records

December 21, 2012 by 58 Comments

3D Printed Record

This is a working record created with a 3D printer. [Amanda] came up with a process that converts audio files into 3D models. These models can be printed and played on a standard record player.

The real work is done by a Processing sketch that creates a STL file. [Amanda] started off by trying to create a sine wave. She used this test to optimize the printing process. Then she used Python to extract audio data from WAV files and modified the processing script to process the data. After more tweaking, she was able to get a reasonable signal to noise ratio and minimize distortion.

The resulting records have a sample rate of 11 kHz and 5-6 bit resolution. The sound quality isn’t going to be the same as commercially pressed vinyl, but you can still make out the song.

A Objet Connex 500 was used to print the records. This UV printer has a 600 dpi resolution, which is means it’s more accurate than extrusion printers. Your mileage may vary using different printers, but all of the Processing and Python code is available with the project write up.

After the break, watch [Amanda] spin some 3D printed records.

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We Are The Borg. We Will Add Heat And Distance Sensing To Your Vision.

December 20, 2012 by 38 Comments

we-are-borg

[Gregory McRoberts] was born with reduced vision in one eye and has never experienced the three dimensional sight which most of us take for granted. Recently he was inspired by the concept of a hearing aid to build a device which can augment his vision. Behold, the very Borg-like eye-patch that he wears to add distance and heat to his palette of senses.

The hardware he chose is an Arduino-compatible Lilypad board. It is wired to an ultrasonic rangefinder and an infrared sensor which monitor the area in front of him. The function of his right eye is still capable of seeing light and color, so a pair of LED boards are mounted on the inside. One is connected to the thermal sensor, displaying blue when below eighty degrees Fahrenheit and red when above. The other LED is green and flashes at a different speed based on the range sensor’s reading.

This is distracting when a person with normal sight wears it because of the intensity of the LEDs. We found [Gregory’s] explanation of this (called Helmet Fire) quite interesting.

[via Adafruit]