Alongside work by Aili Kurtis, Paul Schibli, Guy Lavigueur, Jennifer Gibbs, Reid MacLachlan, John Roth, and Tony Broderick, I’m debuting work exploring new themes for me: a light piece controlled by the colour of the sky.

The light patterns displayed by Sky Spectrum are directly related to the current sky conditions above Ottawa’s Peace Tower.  Every few minutes, the sky portion of the Hill Cam is analysed to reveal the average red, green, and blue components present in the sky.  The light fixture responds according to the various relationships between these values, presenting an altered view of the sky above, revealing colour details and relationships invisible to the naked eye.

The literal reference to the sky is echoed by the graphic processing portion of the piece which takes place on a remote webserver, in essence utilizing “cloud computing.”

Most of the work indeed takes place on my webserver, where a PHP script analyses the current Hill Cam pic with the GB library.  A small hardware module (hidden in the gallery) consisting of an Arduino development board and ethernet shield fetches the data from the web every few minutes, and sends the data via XBee radio to the light fixture, which is controlled by a custom board with an ATmega328 (running the Arduino bootloader), TLC5940 for driving the LED strips, and an XBee.

The code is only preliminary at this point, and I plan to analyse the daily data collected from the sky to make a growing library of light patterns and blends.  I’m also excited about how scalable the concept is, and look forward to working with this idea on a larger scale.

The Phenomena exhibition runs until Feb. 27, so if you’re in the Ottawa area, please drop by CUBE Gallery (1285 Wellington Ave., W) to check it out.  The best time to view Sky Spectrum is between 4 and 6 pm when the sun is setting and the sky changes relatively quickly

I particularly resonated with this quote from the artist:

I am interested in the idea of generative art and rendering the patterns on the fly, but have not found a way to generate compelling sequences enough of the time.

The final version will probably have a black/smoked case with a choice of red or green LEDs.

Not sure if the buttons will be on the side or the bottom yet — which would you prefer?

A few more pics from the prototyping stage of DOTKLOK (see my introductory blog post here.

I’ve soldered my prototyping circuit together:

Next up: a user interface (buttons!) and writing lots of time animations . . .

[ Eyebeam bio ]

Working with Hernani Dias on the Re:Farm project (see my previous post for some more info about the Re:Farm project), my first objective is to create the PCB for the Re:Farm On The Wall module, a data visualization module using an LED display to present data away from the computer screen.

[ details after the break ]

Here’s Hernani’s original sketch for displaying the soil moisture level from 6 sensors:

This design uses 7 LEDs to display the soil moisture level for each of 6 sensors (42 in all). The design concept has been formalized as seen below:

The module still has 7 LEDs for each sensor (or farm/garden), but with the addition of LEDs between the groups (for a total of 48) to create a complete circle which can be used with other templates, such as the one below, for visualizing other data such as temperature or humidity:

Ideally, the board will also incorporate a stepper motor to drive a needle (like a speedometer) for an additional data channel.

I’m going to first concentrate on the LED display. Since the board will make use of an ATMEGA microcontroller (Arduino) chip and an XBee radio (to receive the data), real estate on the approx. 3″ x 3″ board is already a bit tight, so I am currently researching Charlieplexing, an LED driving scheme which allows N*(N-1) LEDs to be directly driven by N pins of the microcontroller. 8 data pins from the microcontroller can thus be used to control the 48 LEDs since Charlieplexing with 8 pins allows control of up to 8*7=56 LEDs.

At The Next HOPE conference this past weekend (blog post about the conference forthcoming), Jimmie P. Rogers was demo’ing and selling his LoL (Lots of LEDs) Shields for the Arduino. He has a great post about his work with Charlieplexing which I’m currently consulting. Talk about serendipity!

In a way, the overlap between the needs of Hernani’s project and my own interests in lighting and internet-enabled lighting fixtures is serendipitous as well.  It’s great to be working on a project that is seemingly so diverse from my own projects, yet has so much overlap on the technical side.

It’s also been interesting to observe Hernani’s design approach/philosophy which stems from his graphic design background.  It seems like everything starts from the aesthetic: the documentation for the project has some of the nicest component diagrams I’ve seen; and even his calendar is created in Illustrator

This presented a perfect opportunity to experiment with interactivity and sensor input for my Electric Window 3 platform.

After sketching out several 1-button game ideas, I decided to move forward with some simple particle systems, controlled by users through their interaction with a single button added to an Electric Window 3 fixture.  Thus was born Electric Window 3B:

[ more info and VID after the break ]

Each time the button is pressed, a new particle (represented by a single LED) is born.  The speed of each new particle is based on the average time between previous births.  Thus, the system has a form of “memory” shaped by previous users.

There are several variants of the particle systems in terms of particle behavior: particles either constantly scroll across the screen and wrap around at the borders; bounce back and forth (or up and down) within the screen; or travel both up and down and side to side, creating the opportunity for collisions.  In the latter case, when the particles collide, they both die.  In all cases, the particle system only has room for so many particles, so after a certain number of births (via button presses), the system resets.  This teases users to find a balance between a “boring” system of few particles versus creating a busy/dynamic system at the risk of killing the whole thing.

The guiding principle was to create an engaging, evolving display from a simple set of rules and user input.

Here’s a video demo:

The curators — Heather Kelly of Kokoromi and Peter Kirn of Create Digital Music/Motion — accepted the piece into the exhibition which took place on March 11-13 2010 at the Gray Area Foundation for the Arts.

I’m now planning to implement particle system animations into future Electric Window 3 fixtures, and more generally, start adding time-based behavior and user input (both direct via buttons etc., and indirect via motion sensors, etc.) to my light fixtures.

It’s always great to have a specific project like this to nudge one along and try out some new ideas and add a new angle to one’s work

This work was generously supported by the art funding program of the City of Ottawa.

Chinatown Remixed runs from May 8 to June 8, 2010, in Ottawa’s Chinatown district. This is the second year for the annual “art walking tour,” where local businesses, restaurants, and shops open their doors to collaborate with artists, providing art “exhibtions in unusual places.”

Last year, Deb and I made a “Chinatown Remixed” sign from electroluminescent (EL) wire, where the various syllables were individually lit, trigged by pedestrian and auto traffic detected by an ultrasonic sensor (see this previous post for details).  This year, the sign is hanging in Umi Cafe (610 Somerset St. W.), although this time driven by random sequences instead of the sensor.

Our new contribution to this year’s event is a window installation at the Oriental Charm gift shop (653 Somerset St. W.):

The installation includes a few light boxes from the Electric Window 4 series:

The main attraction, however, is a group of new Electric Window 3 light boxes, that in addition to their usual geometric and video game -inspired patterns, display messages from Twitter:

[After the break: how it all works and pics of opening day ]

By tagging Twitter messages (Tweets) with the hashtag #CTRM, anyone with a Twitter account can add messages to the installation archive. Between the various animations displayed by the boxes, the boxes query Twitter for new messages (tagged with #CTRM), and if a new message is found, the strobe lights flash and the new message is displayed across one of the boxes:

If no new messages are found, an older, archived message from the #CTRM stream is displayed, but without strobes: the strobes are only used to excitedly punctuate new Tweets

The technology

Here’s a block diagram of the system:

[ bigger version here ]

Starting at the left, there are 4 LED SCREEN light boxes, each with a corresponding STROBE light (only 1 of each is shown). Each LED SCREEN light box has an XBee radio which allows it to communicate wirelessly with the master CONTROLLER. When one of the LED SCREEN light boxes needs a new text string to display, it sends a request via XBee to the master CONTROLLER.

In addition to an XBee radio, the master CONTROLLER also has a WiFi chip which connects wirelessly to the internet (via a wireless router provided by the venue, not shown). When the CONTROLLER receives an XBee request for a new text string, it sends a command to execute a custom PHP script hosted on my website; after a short delay, the CONTROLLER reads the contents of a txt file also hosted on the website.

The PHP script requests the #CTRM stream from Twitter.com, and formats the results for display on the LED SCREEN, it also archives the messages locally on my website; if there is a new Tweet, this is placed in the txt file that the CONTROLLER reads, otherwise an archived message is placed in this txt file. The PHP script also filters the Twitter messages for a list of unapproripate keywords to avoid vulgarities.

If the master CONTROLLER returns a new message to the LED SCREEN, the STROBE lights are also activated for a few seconds to indicate a new message.

The motivation of having the LED SCREEN boxes connected wirelessly to the CONTROLLER was to be able to install the system on-site without having to run a wired serial bus between all the light boxes and the CONTROLLER. Cost was the main motivation for using multiple XBee points connected to one WiFi/ethernet point rather than adding WiFi to each LED SCREEN box. WiFi was chosen for the CONTROLLER so I didn’t have to worry about its placement relative to the internet connection.

Ideally, the STROBE lights would be wirelessly controlled also, but these were a last minute addition to the system — after discovering them in a local dollar store (!) — and are simply wired directly to, and controlled by, the master CONTROLLER with individual power connections; this saved the time, effort, and cost of developing a network to control them, or modifying the LED SCREEN boxes to support them as peripherals. An improvement for the next iteration, perhaps . . .

The exhibtion

Prior to the opening, Deb and I installed the Twitter-enabled boxes within the already-colourful window display at Oriental Charm:

The WiFi controller is located below the display; unfortunately I didn’t take time to snap any pics of it before installing the system so I’ll have to add those later.

Deb designed a great instructional poster for the installation, so we hung that in the window as well:

Here’s the press release we sent out as well, which succinctly describes what to expect from the installation.

On opening day, we did lots of demos, showing people how to add messages to the archive and have them displayed on the boxes:

For those without a Twitter account, or a Twitter-enabled phone (of which there were many), we had a laptop on hand for people to participate through our Twitter account:

Overal, people got a kick out of participating by contributing their own content to the exhibit, and enjoyed the near-immediate gratification of seeing their messages appear with the strobe lights.

We were amused when a friend from Toronto started sending in some “amusing” tweets.

The exbition runs until June 8, 2010. If you’re in the Ottawa area, please check it our for yourself and add some messages! Oriental Charm is located at 653 Somerset St. W., near Bronson, right beside Shanghai Resto.  You can of course participate from anywhere, though, by Tweeting w/ #CTRM

Here’s a few more pics; being a lighting installation, it’s best viewed at night!

Happy to have everything installed, we’re already working on bright ideas for next year

We’d also like to thank the City of Ottawa for its gracious support of this project.

This series revolves around a matrix of 16 LEDs with individually controlled brightness and fading, making it an organic/analog sibling to the 3.xx series which uses LED screens with a large group of on/off, or binary/digital behaving pixels.

Development of this series was fairly straightforward, extending on the work done for the Orion light boxes last spring, with the hardware based on the TLC5940 LED driver, controlled by an Arduino (and using Alex Leone’s great TLC library).

On the software side, it became an exercise of “how much content can I write for 16 LEDs?”  Although the Orion boxes simply simulate a twinkling star field, the orderly grid of Electric Window 4.xx demanded more than mere randomness.

So I wrote a series of pattern-generating functions using sinusoidal values to create soothing waves, adapted some of the grid-filling patterns from Electric Window 3.xx, along with a few other routines that specifically address the 4 x 4 grid of this series by randomly toggling the brightness values of rows and columns to create evolving greyscale patterns.

Diffusing the LEDs with acrylic gives the display a nice ghostly aesthetic.   Here’s a video of the results:

For demonstration purposes, the video shows the patterns changing quite quickly, but in actuality, the pattern speeds vary between slow and serene and speedy and frantic.  I’m really happy with the results, and this is one of my favorite series so far.

The finished pieces are 5″ x 7″ x 2″ and will be individually numbered:

I plan to make a batch of these in various other colours; and although I really like the monochromatic look, I’m sure an RGB version isn’t too far off.

I’m also considering getting a custom PCB made based on this design so I can easily scale it to bigger grids for bigger fixtures.

In the meantime, for anyone interested in a fully assembled piece, I’m also offering these at my on-line shop.

We were pretty pleased with our first attempt at constructing and gluing a 3D object from acrylic.

The LED matrix and controller are from SeeedStudio, and the next steps for us will be to develop content for the LEDs, and refine the acrylic enclosure design.

Another consideration will be whether to stick with a corded DC adapter for power, or go with (rechargeable) batteries.  The pro for a DC adapter is that it takes no additional space in the enclosure, while the flip-side con of batteries is that the extra space required in the enclosure may affect the aesthetics.  Batteries will also need to be recharged or changed as a trade-off for going cordless.  What would you prefer (let me know in the comments)?

Here’s a few more pics:

And a last one for scale:

More pics and video to come as things develop here in the lab!

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