We saw this one a few days ago when it was first bouncing around the interwebs but never took a close look at it. Today, when we ran across a direct link in the tips box it was the promo video (embedded after the break) that won us over. Once you dig into the particulars of The Verbalizer we think you’ll agree that this is a hackable conference badge without the pesky need to attend a conference.
As you probably guessed from the design of the PCB, this is a microphone. It’s intended for use with Google’s new voice search feature, and connects to a computer via a Bluetooth module. But really it’s just another roll-your-own Arduino with a few extra bits. You’ll find an ATmega328 and an FTDI chip which provides a USB connection for programming. The real fun starts with the microphone and speaker circuitry which is just waiting to be breadboarded at home. We found a few other things while poking around in the schematic (available by downloading their Product Docs and Schematics package). It looks like there’s some capacitive touch… you what? Isn’t it more fun if you find this stuff yourself, kind of like the hidden gems of the DEFCON badges?
Continue reading “A badge without a conference”
Like most other DSLR cameras that feature video recording, the Canon T1i has a small built-in microphone with limited sound reproduction capabilities. [Robb] wanted better audio performance while taking video, but found the camera’s inability to use an external microphone to be a frustrating limitation. He decided to take matters into his own hands, and disassembled his camera in order to add an external microphone jack. The process is not overly complicated, as it requires little more than the installation of a switching microphone jack. You will however need to get your hands a bit dirty since it involves opening the camera, a bit of drilling, and some epoxy. Doing such things to your camera clearly voids the warranty, and with a $600 camera at stake, this hack is definitely not for the faint of heart. That said, if you desperately want to get better quality audio from your Canon T1i or 500d DSLR, be sure to check out his tutorial.
Here is a low component count FM transmitter. It sacrifices some features, like the ability to adjust the frequency, for simplicity’s sake. The build method is fairly common with amateur radio but we don’t see it around here too much. Each component gets a 5mm-by-5mm copper clad pad which is super glued to the ground plate as an insulator. There’s even a pictorial example of this method if you need some help with visualization.
One of the schematics included in the article shows how to incorporate a condenser microphone into the unit. We guess that makes it pretty easy to add an FM ‘bug’ to your arsenal of covert listening devices. Just make sure to check your local laws before building and using this. We’re not sure what the FCC would think of it here in America so we’re hoping some well-informed readers will educate us with a comment.
Here’s a surprisly simple way to build yourself a laser-based listening device. It consists of two modules, a transmitter and a receiver. The transmitter is a set of lasers, one is visible red for aiming, and the other is infrared for measuring the vibration of a surface. Point the transmitter at the window of the room you want to listen in on and the laser can be reflected back to the receiver. The receiver module has a phototransistor to pick up the infrared laser light, and an LM386 audio amplifier to generate the audio signal sent to a pair of headphone. The need to be well-aligned which is easy enough using a pair of tripods. Check out the demo after the break.
Looking for something to do with the leftover laser diodes from this project? Try making yourself a laser microscope.
Continue reading “Laser mic makes eavesdropping remarkably simple”
[Dan Hemingson’s] been refining a design for building a tetrahedral ambisonic recording system. This is a set of four microphones used to record audio that can later be mixed down for a three-dimensional listening experience. His goal is an easy and inexpensive build while maintaining the highest fidelity standards possible. Lucky for us he’s made a set of extremely detailed build instructions you can use to make your own. In addition to the mounting bracket seen above he has also developed a pre-amp module that connects to the four mics; it’s part of the build instructions with schematic and board layout files available as well.
This art piece makes drawings based on sound. [Mario Marchese], who is responsible for those illusion props back in february, built this little guy out of a bunch of junk he had lying around. It features four microphones that listen to ambient sound and feed the signal through some LM386 audio power amplifiers. The output is translated into forward, backward, left, and right movements of the writing platform while the pen is fixed in the same position. Despite what we said in the title of the post this isn’t strictly a CNC machine, but more the primordial cousin of one.
Although we’ve covered DIY ECGs before, [Scott Harden] sent in his version that gives an in-depth explanation of what to do with the collected data. He built a basic battery-powered op-amp-based ECG for under $1. The circuit just amplifies the signal from the chest leads and feeds it into a computer via the microphone port. He then used GoldWave to record, filter, and save the signal. From there, he used python to analyze the heartbeat and calculate his heart rate and further manipulate the data. His previous blog posts go into more detail on how the python code works and why he chose software over hardware filters.