Turntable Sequencer Keeps the Techno Beat

We’ve got to admit, we don’t have any idea what to call this hack. Artist [Graham Dunning] refers to it somewhat dryly as the “Mechanical Techno method”, but that doesn’t quite do it justice. We’re thinking “Turntable-sequencer-synthesizer-beat-box-dub-stepper thingy. With cowbell.”

Call it what you will, but [Graham] has really gone the distance in extracting as much sound as possible from the humble turntable, which is used as more of a synchronizer than a sound source. Although it does play records too – at least part of them; [Graham] masks the grooves and anchors the tone arm so that only part of a track is played. Other records are masked with conductive film over which wiper contacts are placed, providing triggers for various synthesizers. Particularly clever is the mechanical percussion section; a record is cut radially to form cams that mechanical followers trip over periodically to hit either the cone of a woofer for bass notes, or a cowbell for – well,  cowbell.

It may not appeal to everyone, but you’ve got to admit there’s something mesmerizing about watching this rig in action. The beat is pretty catchy, and as you can see in the live performance video after the break, there’s a lot of room for [Graham] to express himself with this instrument. We wouldn’t mind seeing how Compressorhead would put this rig to work in their performances either.

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Defeating Chip and PIN With Bits of Wire

One of many ways that Americans are ridiculed by the rest of the world is that they don’t have chip and PIN on their credit cards yet; US credit card companies have been slow to bring this technology to millions of POS terminals across the country. Making the transition isn’t easy because until the transition is complete, the machines have to accept both magnetic stripes and chip and PIN.

This device can disable chip and PIN, wirelessly, by forcing the downgrade to magstripe. [Samy Kamkar] created the MagSpoof to explore the binary patterns on the magnetic stripe of his AmEx card, and in the process also created a device that works with drivers licenses, hotel room keys, and parking meters.

magspoofThe electronics for the MagSpoof are incredibly simple. Of course a small microcontroller is necessary for this build, and for the MagSpoof, [Samy] used the ATtiny85 for the ‘larger’ version (still less than an inch square). A smaller, credit card-sized version used an ATtiny10. The rest of the schematic is just an H-bridge and a coil of magnet wire – easy enough for anyone with a soldering iron to put together on some perfboard.
By pulsing the H-bridge and energizing the coil of wire, the MagSpoof emulates the swipe of a credit card – it’s all just magnetic fields reversing direction in a very particular pattern. Since the magnetic pattern on any credit card can be easily read, and [Samy] demonstrates that this is possible with some rust and the naked eye anyway, it’s a simple matter to clone a card by building some electronics.

[Samy] didn’t stop there, though. By turning off the bits that state that the card has a chip onboard, his device can bypass the chip and PIN protection. If you’re very careful with a magnetized needle, you could disable the chip and PIN protection on any credit card. [Samy]’s device doesn’t need that degree of dexterity – he can just flip a bit in the firmware for the MagSpoof. It’s all brilliant work, and although the code for the chip and PIN defeat isn’t included in the repo, the documents that show how that can be done exist.

[Samy]’s implementation is very neat, but it stands on the shoulders of giants. In particular, we’ve covered similar devices before (here and here, for instance) and everything that you’ll need for this hack except for the chip-and-PIN-downgrade attack are covered in [Count Zero]’s classic 1992 “A Day in the Life of a Flux Reversal“.

Thanks [toru] for sending this one in. [Samy]’s video is available below.

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A 3D Printed Car Jack? No, Seriously!

Ah nuts, I lost my car jack again. What will I do? Well, why not 3D print a new one?

Uploaded to Thingiverse earlier this week, this design allows you to 3D print a fully functional car jack — provided your build platform is large enough. It’s actually a bit of a promo for the Cheetah 2, a massive modular 3D printer by [Hans Fouche]. Earlier this year we shared his 3D printed lawn mower; which spoiler, also works.

The neat thing about the Cheetah 2 is that it doesn’t use filament. It actually processes plastic pellets right inside the hot end, allowing for much cheaper material — typically dollars on the kilogram, as opposed to the $30+/kg we’re all used to being gouged on. Of course, you could also make your own filament. Continue reading “A 3D Printed Car Jack? No, Seriously!”

APRS Repeaters Get the Signal Out of Mammoth Cave

APRS Cave-Link uses the amateur radio’s Automatic Packet Reporting System (APRS) inside caves to get their position data (and other messages) out.

Imagine that you’re coordinating a large scale search-and-rescue mission in a cave. You need to know where all your groups are, and whether or not they’ve found anything. But how do they all communicate to the command center?

You’d guess radio, but you’d guess wrong. Radio doesn’t propagate well at all in a maze of twisty passages, all alike; rocks absorb radio waves, especially in the VHF/UHF range that’s best suited for most small radios. In the past, you’d run wire and transmit along it. This article runs through the options in detail. But adding miles of wire to your already heavy caving and climbing gear is a nuisance or worse.

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The Internet of Minecraft Things is Born

Minecraft has come a long way since [Notch] first thought up the idea that would eventually make him a billionaire. The game can be enjoyed on so many levels and become so engaging that grown adults who should know better spend far more time playing it than working on, say, their backlog of Hackaday posts. As if that weren’t bad enough, now Minecraft threatens to break out of screen with the ability to control a WiFi light bulb from within the game.

For those unfamiliar with Minecraft, it’s an open world game that allows players to interact with blocks of various materials. Players can build, destroy, explore and create landscapes and structures. An active modding community contributes everything from cosmetic texture packs to new block types with extended functionality. It was one of these mods that was leveraged to “break the fourth wall” in Minecraft. [giannoug] used the OpenComputers mod, which allows placement of programmable in-game computers with a full complement of peripherals, including an Internet connection. That allowed [giannoug] to send commands to his Brand X eBay WiFi light bulb, the protocol for which his friend [Thomas] had previously reverse engineered. Flip a switch in Minecraft and the real-world light bulb comes on instantly. Pretty cool.

We’ve seen quite a few builds where Minecraft blocks inspired real-world lamps, but this is a step beyond and might be a great way to get kids into programming using Minecraft. But it’s not the first time Minecraft has broken the fourth wall – check out this 2012 effort to build a microcontroller-based Minecraft server that can toggle pins from within the game.

[Thanks to aggvan and Stathis K for the near-simultaneous tips!]

A Clockwork Cradle is Baby’s First Escapement

[Scott] doesn’t have any kids, but he’s the sort of type that likes to get ahead of the game. Of course this means spending time in his garage to build a rocking cradle. Usually, these are acquired from a baby shower and are powered by batteries. Terribly uncool, considering a mechanism to keep a pendulum swinging has existed for hundreds of years now. His latest project is the escapement cradle – a cradle (or hammock) that keeps rocking with the help of falling weights.

cradle-escapementThe first video in this series goes over the inspiration and the math behind determining how much energy it will take to maintain a swinging pendulum. The second video goes over a very rough prototype for the escapement mechanism with some woodworking that looks dangerous but is kept well under control. The third video puts everything together, rocking a cradle for about 10 minutes for every time the weight is lifted to the top.

[Scott] has had a few of his projects featured on Hackaday, and he’s slowly becoming the number two mechanized woodworker, right behind [Matthais]. He recently put the finishing touches on the expanding wooden table we saw a year ago, and there are surely even cooler builds in the queue for his YouTube channel.

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Hack a Cake

What’s a hacker going to do with an oven? Reflow solder? Dry out 3D printing filament? If you are [Alicia Gibb] you’d be baking a cake. While complaining that projects aren’t a hack seems to be a favorite past time for Hackaday commentators, we think [Alicia] will be in the clear. Why? Because these cakes have Arduinos, LEDs, and motorized candles among other gizmos.

The Game Boy cake is undeniably cool, although we have to admit the cake that screams when cut got our attention (see video below), even if it would unnerve guests.

As you might expect, you can’t bake the electronics directly into the cake. [Alicia] uses Tupperware or parchment paper to create cavities for the electronics. Connections and other solder joints get professional grade Saran wrap to keep the lead and other awful chemicals out of the cake.

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