RaspiReader, An Open Source Fingerprint Reader

September 4, 2017 by Jenny List 14 Comments

In 2008, the then German interior minister, [Wolfgang Schäuble] had his fingerprint reproduced by members of the German Chaos Computer Club, or CCC, and published on a piece of plastic film distributed with their magazine. [Schäuble] was a keen proponent of mass gathering of biometric information by the state, and his widely circulated fingerprint lifted from a water glass served as an effective demonstration against the supposed infallibility of biometric information.

Diagram showing the fingerprint reader's operation. — Diagram showing the fingerprint reader’s operation.

It was reported at the time that the plastic [Schäuble] fingerprint could fool the commercial scanners of the day, including those used by the German passport agency, and the episode caused significant embarrassment to the politician. The idea of “spoofing” a fingerprint would completely undermine the plans for biometric data collection that were a significant policy feature for several European governments of the day.

It is interesting then to read a paper from Michigan State University, “RaspiReader: An Open Source Fingerprint Reader Facilitating Spoof Detection” (PDF downloadable from the linked page) by [Joshua J. Engelsma], [Kai Cao], and [Anil K. Jain] investigates the mechanism of an optical fingerprint reader and presents a design using the ever-popular Raspberry Pi that attempts to detect and defeat attempts at spoofing. For the uninitiated is serves as a fascinating primer on FTIR (Frustrated Total Internal Reflection) photography of fingerprints, and describes their technique combining it with a conventional image to detect spoofing. Best of all, the whole thing is open-source, meaning that you too can try building one yourself.

If [Cao] and [Jain] sound familiar, maybe it’s from their Samsung Galaxy fingerprint hack last year, so it’s neat to see them at work on the defense side. If you think that fingerprints make good passwords, you’ve got some background reading to do. If you just can’t get enough fingerprints, read [Al Williams]’ fundamentals of fingerprint scanning piece from earlier this year.

Via Hacker News.

Stunning Fake Polaroid Camera Performs Magic

August 31, 2017 by Anool Mahidharia 39 Comments

It’s high time us Muggles got our hands on the hardware used to take Magical Photographs as seen in The Daily Prophet. The first pioneering step in that direction has been taken by [Abhishek] who built this moving picture taking polaroid-ish camera, which he’s calling the “Instagif NextStep”. It’s a camera that records a short, three second video, converts it to GIF and ejects a little cartridge which displays the animated photo.

This amazing piece of hardware has been painstakingly built, and the finished product looks great. The nice thing about building such projects, in [Abhishek]’s own words, is that “it involves a bunch of different skill sets and disciplines – hardware, software, 3D modeling, 3D printing, circuit design, mechanical/electrical engineering, design, fabrication etc that need to be integrated for it to work seamlessly.”
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Repurposing Moving Coil Meters To Monitor Server Performance

August 31, 2017 by Dan Maloney 11 Comments

Snazzy analog meters can lend a retro flair to almost any project, but these days they often seem to be retasked as indicators for completely different purposes than originally intended. That’s true for these Vu meters repurposed as gauges for a Raspberry Pi server, and we think the build log is as informative as the finished product is good-looking.

As [MrWunderbar] admits, the dancing needles of moving-coil meters lend hipster cred to a project, but getting his Vu meters to cooperate and display network utilization and disk I/O on his Raspberry Pi NAS server was no mean feat. His build log is full of nice details on how to measure the internal resistance of the meter and determine a proper series resistor. He also has a lengthy discussion of the relative merits of driving the meters using a PWM signal or using a DAC; in the end, [MrWunderbar] chose to go the DAC route, and the video below shows the desired rapid but smooth swings as disk and network usage change. He also goes into great depth on pulling usage parameters from psutil and parsing the results for display on the meters.

Looking for more analog meter goodness? We saw a similar CPU load meter a few months back, and there was this mash-up of Nixies and old meters for a solar energy CEO’s desk.

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Toy Dash Turned Gaming Interface

August 30, 2017 by John Baichtal 15 Comments

We see a lot of MAME cabinets and other gaming emulator projects here on Hackaday, but it’s not often that we see one the form factor of which so elegantly matches the ROM. [circuitbeard] converted a Tomy Turnin Turbo toy dashboard into a mini arcade machine playing Outrun.

There are many fascinating details in [circuitbeard]’s writeup. His philsophy is to “keep it looking stock” so he went to great lengths to add functionality to various elements of the toy without changing its appearance. The gear shifter was turned into a 3-way momentary switch with high and low speeds at top and bottom, with rubber bands pulling the switch back the center (neutral) when he lets go of it. The original toy’s steering wheel mounts to a slide potentiometer. The dash has a working ignition switch that uses a PowerBlock to manage the safe startup and shutdown of the Pi. The dash also lights up the way you’d expect, and even displays accurate MPG and rev info.

For more MAME goodness here on Hackaday, see this broken tablet turned into a mini MAME cabinet or the portable MAME system of the future

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Turning On Your Amplifier With A Raspberry Pi

August 27, 2017 by Jenny List 17 Comments

Life is good if you are a couch potato music enthusiast. Bluetooth audio allows the playing of all your music from your smartphone, and apps to control your hi-fi give you complete control over your listening experience.

Not quite so for [Daniel Landau] though. His Cambridge Audio amplifier isn’t quite the latest generation, and he didn’t possess a handy way to turn it on and off without resorting to its infrared remote control. It has a proprietary interface of some kind, but nothing wireless to which he could talk from his mobile device.

His solution is fairly straightforward, which in itself says something about the technology available to us in the hardware world these days. He took a Raspberry Pi with the Home Assistant home automation package and the LIRC infrared subsystem installed, and had it drive an infrared LED within range of the amplifier’s receiver. Coupled with the Home Assistant app, he was then able to turn the amplifier on and off as desired. It’s a fairly simple use of the software in question, but this is the type of project upon which so much more can later be built.

Not so many years ago this comparatively easy project would have required a significant amount more hardware and effort. A few weeks ago [John Baichtal] took a look at the evolution of home automation technology, through the lens of the language surrounding the term itself.

Via Hacker News.

Raspberry Pi Is The Brains Behind Automated Greenhouse

August 26, 2017 by Steven Dufresne 31 Comments

[Asa Wilson] and his wife picked up a 10’x12′ greenhouse from Harbor Freight that for their location required some serious changes, understandable since they’re in Colorado on the western slope of Pike’s Peak where the winds are strong and the normal growing season is short. After assembling it on a concrete footing and adding some steel bracing, they got to work on adding an environment management system based around a Raspberry Pi. Read on for a look at the modifications they made.

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PiCorder: Raspberry Pi Stands In For Stone Knives And Bearskins

August 18, 2017 by Al Williams 26 Comments

In a classic episode of Star Trek, Spock attempts to get data from a tricorder while stuck in the 1930s using what he described as “stone knives and bearskins.” In reality, he used vacuum tubes, several large coils, and a Jacob’s ladder. Too bad they weren’t in the year 2017. Then Spock could have done like [Directive0] and used a Raspberry Pi instead. You can see the result in the video below.

The build starts with a Diamond Select Toys model tricorder. The Raspberry Pi, a battery, a TFT screen, and a Pi Sense Hat make up the bulk of the build.

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