Dropping The Nitrogen Bomb In Science Class

September 20, 2012 by 40 Comments

We took Geology in college. It was pretty cool learning about the hardness of different minerals. But there were no explosions involved. We’re not entirely sure what this class is, perhaps Chemistry, maybe Physics, but we want in. [Dr. Roy Lowry] wows the class with a bomb made of liquid nitrogen. The demonstration was part of his lecture at Plymouth University.

A small explosion is cool, but [Roy] knows how to add the wow factor. To make the bomb he filled a one liter plastic bottle about 1/3 of the way with liquid nitrogen. After tightly sealing the cap it was dropped in that garbage can which had a pool of warm water in it. Before quickly running away he and his assistant dumped a few garbage bags of ping-pong balls on top of it all. When the plastic bottle bursts under the pressure of the expanding gas it sends the garbage can about six feet into the air and floods the room with bouncing white balls. See the whole presentation for yourself in the clip after the break and don’t forget the sound so you can catch the oohs and aahs at the end.

Looks like a Hackerspace recruitment tool if we’ve ever seen one.

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Key Code Door Lock Won’t Endanger Your Security Deposit

September 20, 2012 by 13 Comments

College students have returned in droves to dorms and apartments at campuses everywhere. So this is the time of year we usually start seeing some coded entry hacks. [Charmonkey] recently took on the challenge at his new apartment. There were some caveats though. He needed to ensure the Landlord could still enter using a key, and he didn’t want to alter the door or the jamb in any way. What he came up with is a coded entry system that can turn the deadbolt.

In order to mount some hardware on the door he removed the inner part of the dead bolt assembly and used the pair of threaded tubes on the adjoining lock section as anchor points. This holds the Pokemon tin he’s using as a project box securely in place. The rest of the components all mount to it. These include the stepper motor that actuates the deadbolt, a switch for manual operation, an Arduino, and a motor driver board.

He got really creative with the keypad. The wires connecting it travel through the door’s peephole and into the smaller plastic project box that hosts the rest of the hardware.

[via Reddit]

How To Build Your Own Dedicated Pandora Radio

September 20, 2012 by 18 Comments

This mix of modern and retro acts as a standalone Pandora client. It’s certainly a radio upgrade, falling somewhere in between the passive listening of traditional broadcasts, and the complete control of music players that use playlists.

Inside the wooden case a BeagleBoard does most of the work. It’s running Ubuntu 12.04 on which pianobar, a command line interface package for Pandora is running. Those components alone would make a pretty nice listening experience, but since Pandora rolls different music into the mix it’s nice to be able to see what you’re listening to. The four-line LCD is wide enough to display plenty of information. It’s being controlled by a PIC24 microcontroller which also monitors the controls on the top. As you can see in the video after the break, the user interface offers almost everything you could want. It’s easy to switch stations, and you can still register your preferences on each track being played.

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Programming An ARM With BASIC

September 20, 2012 by 55 Comments

For those of us old enough to remember the beginnings of the microcomputer revolution, we can look back fondly on ‘the programming environment is the OS,’ a ton of BASIC programs, and typing in small programs found in the backs of computer magazines. It’s a whole new world now with cell phones and Linux computers the size of credit cards, but some companies still remember the beginning.

Coridium is releasing an ARM microcontroller in the vein of old fashioned microcomputers updated for the 21st century. Based on the LPC1114 Cortex M0 ARM microcontroller stuffed into a DIP28 package, the Coridium ARM BASIC provides a programming environment in the firmware.

The ARM BASIC is a complete system on a chip, with Rx and Tx connections to connect to a serial terminal. To get this BASIC microcontroller up and running, all you’ll have to do is connect 3.3 Volts of power. Then, it’s a simple matter of plugging in an FTDI cable and pretending it’s 1989.

Coridium is planning on giving away a few hundred of these ARM BASIC chips to makers in a few days. I’ll put up the announcement of free microcontrollers up in a few days, but [Bruce] at Coridium is sending me one very shortly. Hopefully I’ll be able to do a demo before the stock of free chips is completely depleted.

VFX1 Virtual Reality Headset LinkBox

September 20, 2012 by 21 Comments

 

[Kevin Mellott’s] take on the VFX1 was to update it so it can be used with modern computers requiring just a USB socket and VGA feed.

The VFX1 is a Virtual Reality Headset that hit the market in the first half of the 90’s. The headset was the first of its kind to hit the home market and was ahead of its time. The VFX1 was developed and marketed by Forte Technologies, who’s assets where purchased in 1997 by Vuzix who now produce modern day Video glasses with optional tracking system.

What [Kevin] has achieved is nothing more than remarkable. The original system required a massive ISA card and a link from this card to the Feature Connector on the display card. [Kevin] did away with the ISA card and FCON replacing it with what he calls the LinkBox. This LinkBox has serial or USB out and accepts stereo/mono VGA input or RGB.

The system can now be used with modern day computers including laptops. Those into VR should really check this out.

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Token Authentication For Gmail Using A EZ430 Chronos Watch

September 20, 2012 by 11 Comments

Two-factor authentication allows you to use your chosen password, as well as a one-time password to help keep your services secure. The one-time passwords traditionally come from a dedicated piece of hardware, but there are also solutions for smart phones. [Patrick Schaumont] shows how a TI eZ430 Chronos Watch can be used to generate authentication tokens. After walking through the process he uses it to beef up his gmail login.

This method of token authentication is often called Time-based One Time Passwords (TOTP). It’s part of the Open Authentication (OATH) initiative, which seeks to sort out the password-hell that is modern computing. A portable device generates a password by applying an algorithm and a private encryption key to an accuarte time-stamp. On the server side of things a public key is used to verify the one-time password entered based on the server’s own time-stamp. In this case the portable device is the Chronos watch and the server is Google’s own TOTP service.

You can do this with other simple microcontrollers, we’ve even seen an Arduino implementation. But the wrist-watch form factor seen here is by far the most convenient — as long as you always remember to wear the watch.

[Thanks Oxide]

Homebrew FPGAs

September 20, 2012 by 25 Comments

Homebrew CPUs made out of logic chips are nothing new, but a homebrew FPGA is another matter entirely. [Joshua] sent in a project he whipped up where he made a single logic cell FPGA.

Despite how complicated and intimidating they are in practice, FPGAs are really very simple. They’re made of thousands of logic blocks capable of transmuting into AND, OR, NAND, and XOR logic gates. These logic blocks are all tied together, and with a somewhat complex hardware design language are capable of becoming a CPU, a micocontroller, or even a video card. Basically, programming a microcontroller tells a chip what to do, while programming an FPGA tells the chip what to be.

To build his single logic block FPGA, [Joshua] used a four-bit multiplexer to hard wire a truth table out of a 74HC174 D-type flip-flop. A bit of Arduino code changes the state of the pins connected to the multiplexer allows for any combination of TRUE and FALSE to be calculated for AND, NAND or XOR logic functions.

Yes, it’s only a single logic block for an FPGA, and if this build were expanded to even a few hundred cells it would be gargantuan. Still, there’s no better way to learn the ins and outs of abstract hardware, so we’ll gladly tip our hat to [Joshua] and his homebrew FPGA.