Year: 2012

Making People Pay For Their Beer At Parties

October 20, 2012 by 39 Comments

A common problem at parties and get-togethers – although we don’t remember this happening – is regulating the amount of alcohol people consume. [Mike] came up with an interesting solution to make sure people don’t drink more than their fill by building a vending machine out of a minifridge that allows you to keep track of how many cans someone has taken.

[Mike] added a magnetic card reader on the side of a minifridge that allows any card with a magnetic stripe – a library card, credit card, or school ID – to serve as a unique identifier for each party guest. This card reader is connected to a Raspberry Pi which handles all the registration and eventual payment processing via Venmo

The mechanical portion of the build is a series of ramps built inside the fridge. At the bottom of this series of ramps, a servo controlled by an Arduino dispenses one can at a time when commanded to by the Raspi. The vending machine has a capacity of only 24 cans, but [Mike] says that could be improved with some CAD designed ramps inside a more modern fridge.

Learning Neuroscience With Cockroach Legs

October 20, 2012 by 23 Comments

Neuroscientists [Tim Marzullo] and [Greg Gage] wanted a way to get kids interested in neuroscience. What they came up with isn’t terribly far from something found in Frankenstein’s lab; by amputating a cockroach’s leg and attaching electrodes, they’re able to listen to the sound of neurons firing. For an even cooler demonstration, they’re able to apply a little bit of current to the leg and make the leg dance to the beat of the Beastie Boys.

The guys published an article in PLOS One and gave a TED talk demonstrating their SpikerBox, as they call their invention, to the masses. The basic idea is to amplify the electricity generated by cockroach neurons firing. By listening in on the neurons with an iPad app, [Tim] and [Greg] can set the threshold of the recording to detect the action potential of an individual neuron, and listen in on exactly what happens when a single neuron fires.

It seems like a great tool to explain the very basics of what a nervous system – and a brain, both cockroach and human – actually is. In the video after the break, you can see [Greg] playing around with individual cockroach neurons. After that, [Greg] plays the Beastie’s High Plains Drifter into the leg making the muscles contract. Truly, The Sounds of Science.

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Continental Europe’s First Maker Faire

October 20, 2012 by 21 Comments

Continental Europe’s first official sanctioned Maker Faire is well underway in the Netherlands, tucked away at the Open Lab Ebbinge in the city of Groningen.

Of course the Groningen Maker Faire will feature cool builds like the bike-mounted workshop built by [Bertoa] we’ve seen and a few wind-powered beach animals inspired by the work of [Theo Jansen]. Also on the schedule are a 3D printed zoetrope, delta robot pick and place, radio controlled submarines, and of course a fleet of electric go karts.

A few of the talks involve a mashup of Google Earth and 3D modeling from [Ronald van Aalst] [Dick Stadaand], and a very interesting talk on disability insurance for self-employed entrepreneurs from [Biba Shoemaker] and [Andre Jonkers].

[buZz] from the NURDspace hackerspace in Wageningen wrote in to tell us he’ll be participating in the Groningen Maker Faire’s Scrapheap Challenge, an awesome contest that pits teams against each other to build something in a setup very similar to the fondly remembered Junkyard Wars.

Of course, Hackaday’s writers and editors are about 3,000 miles away from continental Europe’s first Maker Faire, so we can’t provide any live updates. If you have any pictures or video, send them in and we’ll put them up.

The Arduino Due Is Finally Here

October 20, 2012 by 81 Comments

After a years-long wait, an ARM powered Arduino is finally due. The Arduino Due will finally be released this coming Monday.

On board the Arduino Due is an Atmel-sourced ARM Cortex M3 microcontroller running at 84 MHz. The Due has an impressive list of features including a USB 2.0 host, compatibility with the Android ADK (lest you still need an IOIO), 12 analog inputs with 12-bit resolution, 2 analog outputs running at 12 bits, a CAN interface, and more input pins than you can shake a stick at.

For a full list of features, you can grab this PDF we picked up when we saw the Due at Maker Faire NYC

This hardware update to the Arduino platform makes a lot of very cool builds very possible for even the beginner hardware hacker. Of course the Due will be used for controlling drones and UAVs, laser cutters and 3D printers, and playing WAV files from the analog outputs. The much improved hardware opens up a lot of other possible builds including making your own guitar pedals – DSP is a wonderful thing – and reading the telemetry from your car in real-time via the CAN bus.

Although it’s not available right now, you will be able to buy an Arduino Due for $49 USD this coming Monday at your favorite electronics retailers. 

Physical Orangered Notifies You Of Reddit Messages

October 20, 2012 by 11 Comments

Anyone who has been around Reddit enough to anger the hive mind is familiar with the orangered, the envelope icon right next to your username that lights up in a beautiful orangered hue whenever you receive a new message. [Brad] wanted an orangered that was a little more visible, so he created a standalone Reddit message indicator to sit on his desk and light up whenever a new message has been delivered.

The case for [Brad]’s new orangered notifier was taken from a cheap thrift store clock. After dispensing of the mechanical movement, [Brad] loaded up the beautiful wooden case with an Arduino, a trio of LEDs, a speaker, and, of course, a small envelope logo reminiscent of Reddit’s message icon.

The Arduino is connected to a laptop running this Perl script. The script scrapes the JSON returned from the Reddit API and sends a command over the serial port to the Arduino if new messages have been received (source for the Arduino and the notes.h header file). When a new message is received, the Arduino lights up the envelope icon and plays a short sound on the attached speaker.

There are a few improvements [Brad] plans to add to his orangered indicator. First up is getting an Ethernet shield and discarding the server attached to the Arduino. Next up is different lights and tones for different types of messages (PMs, comment replies, and mod mail). Of course the top of our list for [Brad]’s future improvements is actually making the LEDs orangered, but it’s still a very awesome build to allow [Brad] to waste even more time on the Internet’s time sink.

Video after the break.

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A Harpsichord That Plays Itself

October 19, 2012 by 20 Comments

[Malcolm Messiter] is an Oboe player who loves to play pieces from the Baroque era. This often means playing with a Harpsichord and he managed to acquire one to call his very own. Unfortunately you can’t play both instruments at once so he set out to automate the keyboard. What you see here is a fully working version, but he soon went on to add solenoids to the upper rank as well. His story starts on page 27 of this newsletter (PDF).

He really went out of his way to make sure the instrument was not mistreated. A cabinet-maker built some brackets to mount the system above the keys. A friend drilled and tapped a sheet of acrylic to which each solenoid was mounted. The solenoid shafts have each been padded with felt to cushion the blow on the keys. We’ve embedded two demo video after the break that show off the first and second versions of the builds.

Harpsichords pluck the strings instead of hitting them with a hammer as the piano does. The mechanism that does the plucking had worn out on many of the keys so [Malcolm] used a 3D printer to help replace them.

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Halloween Props: Spooky Eyes Light Up The Bushes

October 19, 2012 by 11 Comments

This is just one example of several pairs of spooky eyes which light up [Vato Supreme’s] bushes this Halloween. The quick and inexpensive build process make it a perfect diy decoration.

Each eye is made up of a ping-pong ball and an LED. But that alone won’t be very spook as the entire ball will glow rather brightly. So he spiced things up a bit by masking off the shape of a pupil and spraying the balls black. The vertical slit seen in white above will glow red like a demon in the night.

The LEDs are driven by an ATtiny85 running the Arduino bootloader. [Vato] found there was plenty of space two write code which fades the eyes in and out using PWM. This happens at random intervals for each of the four pairs he is driving.

We’ve seen a similar project that used oversized LEDs as the eyes. But we really like the idea of using a diffuser like this one. See it in action after the break.

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