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Published on: September 26, 2013 / Comments: None

Building a noise generator with transistors

Believe it or not, it’s actually quite difficult to generate random numbers on computers and microcontrollers.  I’m talking about true random.  A lot of the randomness computers use isn’t random at all, it’s predictive (or pseudo random).  Difficult, but still predictive.   It’s important when doing cryptographic functions to use a good random source.

So f4grx decided to build a random circuit and do some analysis on it.  The circuit design is built around the idea of using an open collector on a transistor.  What’s essentially going to happen is tiny electrical noise in the air is going to cause the circuit to produce 1′s and 0′s which then can be used to plot random.

Interesting read.  Check out f4grx’s experience.

Published on: September 26, 2013 / Comments: None

Trim the fat out of your Pi

Need to stick that Raspberry Pi in a tight spot ?  Or is it just a little to big for your enclosure ?  Finn has some ideas how to shed some size off of the Pi for a slimmer fit.

The first mod is the obvious one, de-solder the RCA video connector (if you aren’t using it).  Next remove the audio jack.  Those will slim it down a little bit in the width.  Now for trimming the length, the biggest problem is the pertruding full sized SD card.

There is a fix for that, you can get a micro-sd adapter that will fit nicer.  Or you can do it the hackalizer way and take some scissors to that SD card.  As it turns out most modern SD cards only use the very tip, the rest is just empty plastic.  Who knew ?

Check out the post on finn’s site.

 

Published on: September 24, 2013 / Comments: None

Do-It-Yourself Raspberry Pi Tablet

Raspberry Pi CameraIntroducing DukePad. A Do-It-Yourself Raspberry Pi tablet running JavaSE Embedded 8. The DukePad design includes a 10″ LCD Display (1280 x 800), a Raspberry Pi, a Raspberry Pi Camera, WiFi, a motion sensor and more which are all encased in an acrylic enclosure (PDF). The parts to build your own open source Tablet will cost you about $370.

The creators are quick to point out that DukePad is demo quality. So don’t expect any ground breaking features out of the box. However, the beauty of open-source is you can make it your own. If you don’t want to buy everything individually be patient because a kit is in the works.

Who knows… maybe you can add your own fingerprint reader for security!

 

Published on: September 23, 2013 / Comments: 2

Hacking iPhone 5S TouchID

Think your iPhone 5S TouchID is secure? Think again. The biometrics hacking team of the Chaos Computer Club (CCC) has successfully bypassed the biometric security of Apple’s TouchID using the How to fake a fingerprints? process they wrote about back in 2004.

“First, the fingerprint of the enroled user is photographed with 2400 dpi resolution. The resulting image is then cleaned up, inverted and laser printed with 1200 dpi onto transparent sheet with a thick toner setting. Finally, pink latex milk or white woodglue is smeared into the pattern created by the toner onto the transparent sheet. After it cures, the thin latex sheet is lifted from the sheet, breathed on to make it a tiny bit moist and then placed onto the sensor to unlock the phone. This process has been used with minor refinements and variations against the vast majority of fingerprint sensors on the market.”

Nothing good could ever come from storing your fingerprints on your smartphone.  Just don’t do it people! You can read more about the iPhone 5s TouchID Hack here.

Published on: September 22, 2013 / Comments: 2

Lazy Sunday Links – 9/22/2013

It’s Sunday again, time to take a break from watching your favorite NFL team lose and learn something somewhat productive.

First up, you should fire up your 3D Printer and make yourself a set of these cool 8bit video game coasters.

Not in the mood for some video game coasters? Well did you know there are more places to get 3D models to print for your 3D Printer other than Thingiverse ?  There’s Defcad which commonly has all those items that people are forced to take down other places, and Yeggi which seems to just scour the web hunting models.  If you are making industrial designs like PCB layout, there’s 3dcontentcentral.  That should get you going.

You’ve obviously heard of FFT or Fast Fourier Transform, you have it on your trusty O’Scope and when you look at it, you think you see valuable information.  But what exactly is a Fourier Transform?  Check out the interactive guide to Fourier Transform so you can learn something.

Looking for somewhere to host your software project, not a fan of GitHub?  Srchub is just starting out, but offers subversion, git, mercurial, wiki, issue tracker.  Lets you assign multiple collaborators and also make private repositories.  Not a bad gig for free.

You JavaScript/Node.js guys have probably seen the Espruino microcontroller.  A micro that can be developed using JavaScript.  But did you know there is another one ?  The Tessel.  This one’s got on-board wi-fi.

Published on: September 22, 2013 / Comments: None

Attiny 2313 V-USB Media Volume Control

I know this awesome project is a few weeks old but I’m going to use the fact that Rupert recently posted an update as my excuse to share it on hackalizer. As the title implies the V-USB Media Volume Control project is using V-USB. V-USB is software which makes it possible to add low-speed USB to almost any AVR microcontroller without any additional hardware.

Inside Volume Control EnclosureFrom selecting the perfect rotary encoder to designing and etching his own PCB and eventually making a custom enclosure, this project shows is all. Rupert explains some of the minor but important differences of the rotary encoder such as the number of detents and amount of force required to turn the knob and press the button.  He also shares an important lesson on load capacitance with regards to the crystal on his home-brew board. Check out the build video after the break.

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Published on: September 20, 2013 / Comments: 1

Remote control aquarium lighting with Raspberry Pi and Node.js

Bryan bought a new aquarium awhile back and some pretty little fish to go with it.  The tank’s lighting system has a day and night mode in order to be a little more realistic for the fish’s natural environment, but you have to physically switch it between day and night.  So as any hacker would do, he hooked a Raspberry Pi up to it and made it remote control!

The hardware control interface is a transistor and a relay connected to the gpio of the Raspberry Pi.  The software interface has a manual mode and automatic mode.  In automatic mode it pulls the sunrise and sunset data from the interwebs and alters the day/night modes accordingly.

Aside from the original article, Bryan decided to go a little deeper on the build with an overview in part 1 and hardware rundown in part 2 where he has the schematic and his pcb layout.

Source code is available on github.  Info on getting node.js up is on the original article. Video demo after the break;

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