A Command-Line Stepper Library with All the Frills

When you already know exactly where and how you’d like your motor to behave, a code-compile-flash-run-debug cycle can work just fine. But if you want to play around with a stepper motor, there’s nothing like a live interface. [BrendaEM]’s RDL is a generic stepper motor driver environment that you can flash into an Arduino. RDL talks to your computer or cell phone over serial, and can command a stepper-driver IC to move the motor in three modes: rotary, divisions of a circle, and linear. (Hence the acronumical name.) Best of all, the entire system is interactive. Have a peek at the video below.

The software has quite a range of capabilities. Typing “?” gets you a list of commands, typing “@” tells you where the motor thinks it is, and “h” moves the motor back to its home position. Rotating by turns, degrees, or to a particular position are simple. It can also read from an analog joystick, which will control the rotation speed forward and backward in real time.

Division mode carves the pie up into a number of slices, and the motor spins to these particular locations. Twelve, or sixty, divisions gives you a clock, for instance. Acceleration and deceleration profiles are built in, but tweakable. You can change microstepping on the fly, and tweak many parameters of the drive, and then save all of the results to EEPROM. If you’re playing around with a new motor, and don’t know how quickly it can accelerate, or what speeds it’s capable of, nothing beats playing around with it interactively.

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Life-Size Vu Meter Gets the Party Started

There’s nothing better than making a giant version of one of your hacks. That is, other than making it giant and interactive. That’s just what [Est] has done with his interactive VU meter that lights up the party.

The giant VU meter boasts a series of IR detectors that change the colors and modes of the meter based on where the user places their hands. The sensors measure how much light is reflected back to them, which essentially function as a cheap range finder. The normal operation of the meter and the new interactivity is controlled by a PIC16F883 and all of the parts were built using a home-made CNC router. There are two addressable RGB LEDs for each level and in the base there are four 3 W RGB LEDS. At 25 levels, this is an impressive amount of light.

[Est]’s smaller version of the VU meter has been featured here before, if you’re looking to enhance your music-listening or party-going experiences with something a little less intimidating. We’ve also seen VU meters built directly into the speakers and also into prom dresses.

Evolving Storytelling to Marry the Ancient Skills with the Digital Age

Storytelling is an art. It stretches back to the dawn of man. It engages people on an emotional level and engages their mind. Paulina Greta Stefanovic, a user experience researcher and interaction designer is on the cutting edge of bringing our technology together with the best human aspects of this long tradition.

The information age is threatening storytelling — not making it extinct, but reducing the number of people who themselves are storytellers. We are no longer reliant on people in our close social circles to be exquisite story tellers for our own enjoyment; we have the luxury (perhaps curse?) of mass market story-telling.

Paulina’s work unlocks interactive storytelling. The idea isn’t new, as great storytellers have always read their audience and played to their engagement. Interactive storytelling in the digital age seeks to design this skill into the technology that is delivering the story. This is a return from passive entertainment.

This breaks down into interactive versus responsive. At its simplest, think of responsive as a video that has a pause button. You can change the flow of the story but you can’t make the story your own. Surprisingly, this is a new development as the ability to pause playback is but a few decades old. So you can pause a responsive medium, but true interactive experiences involve creation — the audience is immersed in the story and can make substantive changes to the outcome during the experience.

This equates to a power transfer. The creator of the media is no longer in complete control, ceding some to the audience. We are just at the start of this technology and it looks like the sky is the limit on what we can do with algorithmic interactions.

Video games are the forerunners of this change. They already have branching stories that let the users make choices that greatly affect the storyline. This industry is huge and it seems obvious that this active aspect of story consumption is a big part of that success. Even more intriguing is a “drama management system” (a new term to me but I love it) that results in a story whose ending nobody knows until this particular audience gets there. What a concept, and something I can’t wait to see for myself!

If you find these concepts as interesting as I do, check out Paulina’s talk below, which she presented at the Hackaday Belgrade conference.

Forbidden Fruit Machine

Here’s another example of how today’s rapid-prototyping technologies are allowing Artists and Craftsmen to create interactive works of art rapidly and easily. [Kati Hyypa] and [Niklas Roy] teamed up to transform a classic painting in to an interactive exhibit. It’s a painting of Adam, Eve and the apple with a joystick attached. Spectators can control the destiny of the apple with the joystick and thus explore the painting.

The “Forbidden Fruit Machine” is based on a painting called “The Fall of Man” created by [Cornelis Cornelisz van Haarlem] in 1592. The painting depicts Eve and Adam in the Garden of Eden, being tempted by the serpent to eat the forbidden fruit. A public domain, high-resolution scan of the painting is available for download from the Rijksmuseum Amsterdam. Starting with that, the arms were edited out, and replaced with articulated versions (mounted on acrylic) driven by servos. The apple was mounted on a X-Y gantry driven by two stepper motors. These are driven by a motor shield, which is controlled by an Arduino Uno. The Uno also controls a Music Maker shield to play the various audio tracks and sound effects. Finally, an additional Arduino Pro-Mini is used to control the LED lighting effects via a Darlington driver and also connect to the end stops for the X-Y gantry. The joystick is connected to the analog ports of the Uno.

The LED’s give clues on where to move the apple using the joystick, and pressing the red button plays an appropriate audio or sound effect. For example, pressing the button over the cat at Eve and Adam’s feet elicits a heart-breaking meow, while letting Eve eat the apple results in an even more dramatic effect including a thunder storm.

The machine is open source with code posted on Github and 3d files on Youmagine. Watch a video after the break. The artist’s names may be familiar to some some readers – that’s because both have had their earlier work featured on our blog, for example this awesome ball sucking machine and another one too.

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Audience Pong and RC Trash bins: An intro to TEI

This past weekend, I had the chance to visit this year’s Tangible, Embedded, and Embodied Interaction Conference (TEI) and catch up with a number of designers in the human-computer-interaction space. The conference brings together a unique collection of artists, computer scientists, industrial designers, and grad students to discuss computer interactivity in today’s world. Over the span of five days (two for workshops, and three for paper presentations), not only did I witness a number of today’s current models for computer interactivity (haptics, physical computing with sensors), I also witnessed a number of excellent projects: some developed just to prove a concept, others, to present a well-refined system or workflow. It’s hard to believe, but our computer mouse has sat beneath our fingertips since 1963; this conference is the first place I would start looking to find new ways of “mousing” with tomorrow’s technology.

Over the next few days, I’ll be shedding more light on a few projects from TEI. (Some have already seen the light of day.) For this first post, though, I decided to highlight two projects tied directly to the conference culture itself.

Before each lunch break, the audience was invited to take part in an audience-driven interactive game of “Collective” Pong. With some image processing running in the background, players held up pink cards to increase the height of their respective paddle–albeit by a miniscule amount. The audience member’s corresponding paddle weight was mapped to their respective marker location on the screen (left or right). It turns out that this trick is a respectful nod back to its original performance by [Loren Carpenter] at Siggraph in 1991. With each audience member performing their own visual servoing to bring the paddle to the right height, we were able to give the ball a good whack for 15 minutes while lunch was being prepared.


Next off, the conference’s interactivity spread far beyond the main conference room. During our lunch breaks we had the pleasure of discarding our scraps in a remotely operated trash bin. Happily accepting our refuse, this bin did a quick jiggle when users placed items inside. Upon closer inspection, a Roomba and Logitech camera gave it’s master a way of navigating the environment from inside some remote secret lair.

Overall, the conference was an excellent opportunity to explore the design space of tinkerers constantly re-imagining the idea of how we interact with today’s computers and data. Stay tuned for more upcoming projects on their way. If you’re curious for more details on the papers presented or layout of the conference, have a look at this year’s website.

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Hack Your Datasheets Using Datasheet.net


If you use datasheets (which is probably every reader of Hackaday) you need to check out this tool that seeks to add modern features to the decades-old component specification delivery system. That link takes you to the announcement of the launch of Datasheet.net.

What you see above is the biggest feature the service brings to the table, the ability to create “snippets” from datasheets by clicking and dragging the area you’d like to save (you can even get a public link to the snippet). Once you have selected a snippet there are a few tools that allow you to make annotations on it. We’ve used the rectangle tool to highlight the clock speed and divider settings in this snippet for an ATmega328 uC. The interface also offers the ability to draw arrows, freehand, or to add text to the snippet. At the bottom of this example we used the description area to notate the fuse settings (in hex) which we most often use with this chip. These snippets and annotations can then be shared with other users of the service, and there’s also a comments section below the snippet for your team to use. See examples of this in the video below.

This solves one of our biggest beefs with PDF datasheets — the ability to jump back and forth and to easily find commonly used sections. This datasheet is 567 pages long and not fun to paw through looking for the same info repeatedly. It also offers rudimentary “favorite” flagging to keep a list of your oft-used sheets — but we’d like to see more options for categorizing our collection. We also find it hard to get by without the Table of Contents functionality we’re used to in our normal document view (evince). We’ve already pestered the lead developer, [Ben Delarre], to add this feature. He’s the same guy who came up with the schematic sharing site CircuitBee. Now would be a great time to mention that this service is owned by Hackaday’s parent company SupplyFrame.

Datasheet.net has a mammoth source of datasheets available through the search, but the list of planned feature additions includes datasheet upload. Also on the list is a “Discussion” feature which sounds interesting to us. What if, through the discussion engine, searching for datasheets also turned up a list of open hardware projects that use this part? We are also drooling over the ability to embed these snippets directly in webpages. [Ben] tells us that’s already built but they didn’t have time to add it to the UI before launch. Gone will be the days of taking screenshots of PDFs for your blog writeup!

PDF delivery of datasheets revolutionized access to information about electronic components. We’re hoping that this marks the next evolution. In addition to better working features, wouldn’t it be nice if you could actually get notifications when new datasheet revisions or errata were published?

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Interactive Punching Bag

If you need a sparring partner, and do not want to be dependent on finding a willing partner at any random time, then maybe this Interactive Punching Bag will be some interest to you. [Lior], having studied Karate for a while now, originally envisioned a robotic arm that would punch at you using the Texas Instruments Chronos or the Microsoft Kinect as input, though after some initial messing around he decided to scrap that plan and thought “how hard is it to place some LEDs inside a punching bag and sense some force using an Arduino?”

After about a day and a half, using parts from around the shop and a trip to radio shack, he was able to complete his goal, and left some room to expand in the future. The bag currently features 3 resistive sensors, 3 LED’s, and is using a laptop for feedback, though an LCD is on its way. The expansion room allows for 3 more sensors and LED’s for twice the action and more complex games.

Speaking of games, the punching bag currently has 3 different exercise programs, as many punches as you can in 30 seconds mode, a programmable sequence mode, and random which occasionally punches back. Join us after the break for a quick video, and check out the page for details and a pile of pictures.

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