Hidden RFID Reader Locks Workstation Unless Keys Are Present

We don’t know how [Kristoffer Marshall] found himself with free time at work, but he used it to beef up his computer security. Above is the finished project. There is literally nothing to see here. He’s rigged up a hidden RFID reader which locks and unlocks his workstation.

The security of the system depends on xscreensaver, which has a password protected lock feature already built into it. When the tag is removed from the reader’s field it fires up the screensaver using a Perl script.

But waking up from the screensaver is a bit more tricky. The package doesn’t allow you to wake it from the command line — most likely for security. He found the xdotool to be of great use here. It is a command line tool which simulates keyboard and mouse entry. His script detects when the xscreensaver password prompt is on the screen and uses the xdotool to fill in [Kristoffer’s] password. Since the script knows what has focus it won’t give away your password by accident.

See the complete setup in the clip after the break.

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Open Hardware Summit 2013 – Part 1: Demos

Open Hardware Summit 2013

The 2013 Open Hardware Summit took place on September 6th at MIT. There was a wide array of demos and talks covering Open Hardware methodologies and projects. After the break I’ll be covering the demo area of the conference, and sharing some of my favorite demos.

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Extruded Rail And 3D Printed Connectors Form A Proper Laser Engraver

3d-printed-laser-engraver

Fast and accurate is a good description of this laser engraver built by [Ragnar] and [Gunnar]. The’re planning to show it off at the Trondheim Maker Faire after the new year but they took it out in the wild for the PSTEREO Mini Maker Faire (also in Trondheim) this past August. The video below gives an overview of the build process and the engraver at work. But we also enjoyed reading the post about a few missteps in the early prototyping process. We call this one a proper laser engraver because it was purpose built from the ground-up. We still like seeing the engravers hacked from optical drives, but this really is a horse of a different color in comparison.

From the start they’re using familiar parts when it comes to CNC builds. The outer frame is made of extruded aluminum rail, with precision rod for the gantry to slide upon. Movement is facilitated with stepper motors and toothed belts, with all of the connecting and mounting parts fabricated on a 3D printer. The mistake made with an early (and unfortunately mostly assembled) prototype was that the Y axis was only driven on one side when it really needed to be driven on both. But filament is relatively cheap so a few tweaks to the design were able to fix this and get the production back on track.

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Potassium Chlorate From Household Products

To the upper right we have very pure potassium chlorate, so much so that it bursts into flames when mixed with sugar and catalyzed with some sulfuric acid. [Mr. Home Scientist] produced the KClO3 using household chemicals and some rudimentary equipment sourced on eBay.

The experiment started off with concentrated bleach containing 8.25% sodium hypochlorite. He needed sodium chlorate so a hot plate was used to boil the bleach until crystals started to form. A more efficient way to achieve this reaction would be using electrolysis (check out the HHO generator we saw recently for a homemade rig). The next step is to add potassium chloride, which is sourced from the grocery store as a sodium-free salt alternative. After mixing with the filtered remains of the bleach reaction the two are combined. There is no precipitate from this — an indication that not everything is as it should be. But an overnight stay in the refrigerator results in the potassium chlorate crystals seen above.

Fiery testing (seen below) lets him know the experiment worked. From here the product can be used for things like making solid rocket engines.

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Pair Of MIDI Dongles To Inspire Some Weekend Music Hacking

pair-of-midi-dongles

This pair of dongles is a fun way to get your feet wet working with MIDI hardware. They’re called MIDIvampire-I and MIDIvampire-II. Just plug one end into your MIDI-ready instrument and the other into a pair of speakers and you’re off and running. Mark I is a polyphonic synth, and Mark II is a drum machine, but both use basically the same hardware which you may already have on hand.

The single chip on each board is an ATmega328 often found anchoring Arduino boards. The other silicon component is an S1112B30MC voltage regulator. The rest of the components are passives, with MIDI and headphone jacks for connectivity. They’re selling these if you want the easy way out, but we thought we’d bring them to your attention in case you needed a breadboarding project this weekend. The firmware, BOM, schematic, and board artwork are all available on the Wiki pages linked in the articles above. After the break you can see a couple of demo videos which walk through all of the features.

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Putting Every Game Console In The Palm Of Your Hand

SNES

Casemodders extraordinaire [Downing] and [Hailrazer] are known for their fabulous builds that put just about every gaming console into a portable hand-held format. Everything from a Game Cube to N64s and a Sega Genesis have been conquered by the two, and for the last year they’ve been putting their heads together to make the best solution to portabalizing console gaming forever. It’s called the Cross Plane, and puts just about everything with an HDMI connection in the palm of your hand.

The build began as one of [Downing]’s more ambitious projects. He imagined a system that could play nearly every retro game on a small handheld device. After finishing this build, he set up a Kickstarter and called up his friend [Hailrazer] to get some feedback. Just hours before the Kickstarter launched, [Hailrazer] suggested making a device for modern consoles. [Downing]’s pride and joy was scrapped, but out of its ashes arose the Cross Plane.

Inside the Cross Plane is a wireless HDMI receiver and a 7″ 720p display. This, along with a few buttons and analog controls, allow the Cross Plane to serve as a remote display and controller for an XBox 360, Playstation 3, and even a PC, for all that retro emulator goodness.

It’s a really, really cool project, and since the dream of an open Wii U controller seem to have died, we’re thinking this could be a great controller for an FPV quadcopter or other remotely operated vehicle.

3D Printering: Electronics Boards

If you’re gearing up to build a 3D printer, one of the first things you’ll need to look at is your options for electronics boards. Whether you decide to optimize for cost or capability, the choices you make during the planning stages of your build will drastically affect what the final project will look like and how it will behave.

There are a ton of electronics boards out there, so for this installation of 3D Printering, we’re going to take a look at what’s available. Hit the link below to give Hackaday more pageviews read the rest.

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