Interactive LED Coffee Tables: Update and kits!

Cool, our interactive LED coffee tables got a mention in the October issue of Popular Science!

What’s an interactive LED coffee table? (Funny you should ask….) It’s a coffee table that has hundreds of LEDs in the top surface that respond to motion above the table. We have (finally) put together a movie to give you a better idea of how they respond to their environment. You can see the movie on YouTube or watch it embedded:

The complete tables are for sale from Because We Can, our partners in design on this project. There are presently two models, The Ripple (left) and The Wave (right):

the ripple

the wave

Since we first showed these off, we have had a lot of inquiries about how you can make your own table like this. We are now producing (very large) electronic soldering kits so that you indeed can make your own.

Our kits include the giant printed circuit boards, components, instructions, LEDs, and all other parts needed to build the electronic portion of the table tops. Constructed, you end up with what essentially amounts to a single extra-ginormous circuit board that can sit underneath the clear or frosted glass (or plastic) top of your own table. Interesting in getting a kit? Click here to read the details!

(Revised 11/16/2007).

Interactive LED coffee tables

BWC's new coffee table

Last year at Maker Faire, we showed off our interactive LED dining table. There, we met the fine folks at Because We Can, who make amazing mostly wooden things with a little help from their robot. We eventually all decided on collaborating to design and build a new series of interactive coffee tables. We’ve just wrapped up the project and are introducing them this weekend at Maker Faire.
Besides what is written about them on this page, you can read more about them on the
Because We Can Blog, and you can also see lots of photos in the product pages for the two different coffee table designs: the wave and the ripple.

The new tables are designed to look really great whether or not you can see the LEDs. The wooden bases are elegant and attractive, and also if you go up to one and touch it, it will respond by pleasantly lighting up in that area. The tables are designed to respond in a subtle and gentle fashion to stimulus provided by human interaction. They are normally dim and constant– the most you’ll see in a dark room is a faint glow of twinkling like the night sky. When you set your glass down on the table, however, the table “sees” the motion that induces a slow ripple starting in that location that spreads out to other areas of the table as it dissipates. The overall effect is a bit like touching a pool of water, in that your local disturbance turns into an overall gentle rippling, and eventually settles down. It is decidedly not a disco floor– there is no blinking, no programmed oscillations, or for that matter, any digital electronics at all– the circuitry is completely analog to improve aesthetics and reduce eyestrain.

Octolively: Digital interactive LED surfaces

Octolively Array: 8 inches wide

Octolively is an all-new, open source interactive LED surface kit that we’re releasing today. Octolively features high resolution– an independent motion sensor for every LED, stand-alone operation, a variety of response functions, and easy scaling for large grids.

Warm white (left), Regular "cool" white (right)

Octolively represents our fourth generation of interactive LED surfaces.

Long-time readers might recall the original Interactive LED Dining Table, the infamous Interactive LED Coffee Tables, or the third-generation, not-very-creatively-named Interactive LED Panels. All of these surfaces were based on fully-analog circuitry with large circuit boards and a fairly high ratio of LEDs to sensors– typically 20:1.

Octolively: single unit, powered down-2

Octolively, by contrast, is based on smaller, lower-cost circuit board modules, “only” 4×8 inches in size. Part of the reason for this is so that there’s more flexibility in making arbitrarily shaped arrays. Arrays can now be as skinny as 4″ wide, or as wide as you like.

Each module features 8 LEDs and 8 independent proximity sensors– one for each and every LED. The LEDs are (huge) 10 mm types, and that chip in the middle of the board is an (also huge) ATmega164 microcontroller.
Each sensor consists of an infrared LED and phototransistor pair, which– together with polling and readout from the microcontroller –acts as reflective motion sensor. The LEDs are spaced on a 2-inch grid, and the edge connectors allow boards to be tiled seamlessly.

Because the circuit is now primarily digital, it’s easy to store a variety of response functions in the microcontroller. Our standard firmware contains 8 different response functions– fades, ripples, shadows and sparkles, which you can change with a button press. As it’s an open source project, we’ll expect that (in time), others will become available as well.

Octolively: 3x3 grid of boards

And, because the entire circuit is self-contained on the module, the surface scales effortlessly– you get very high resolution over huge areas without bandwidth bottlenecks, and no need for a central computer.

Of course, static pictures don’t do much justice for interactive LED surfaces. (We’ve embedded our video above. If you can’t see it here, click through to YouTube.)

Octolively, warm white LEDs

And doesn’t that look good with warm white LEDs?

Octolively begins shipping next week. Additional details– including the datasheet and documentation links –are available on the product page.

Roasting coffee at home: a DIY coffee bean cooler

Coffee Cooler - 03 Coffee Cooler - 01
Coffee Cooler - 18 Coffee Cooler - 09

I never really set out with the goal of roasting my own coffee beans, it just kind of happened.

It started a month ago when we got a coffee grinder. Naturally we started getting whole bean coffee, which we used at a rate of about one pound per week. While I’m not (by any standards) a coffee connoisseur, I found myself noticing that the first pot of coffee out of the new can really was just better than the last pot of coffee out of the old can– meaning that the coffee quality does actually decline noticeably after just a week.

Now, that’s a minor annoyance, and hardly cause for action. But, two weekends ago I happened to be browsing in a home brewing store (needed champagne yeast– that’s another story) where there were sealed bags of green coffee beans just sitting there on the shelf. Fair trade, organic, and in a number of varieites. Only 5 bucks a pound. So what the heck, right?

It turns out that there’s a common and cheap method of roasting coffee at home: using a regular air popcorn maker. You put the beans in the popper as though they were popcorn kernels, heat them for a few minutes until they’re properly roasted, and then cool them. (You can read the details of this process here, here, here, and here, amongst other places.) This is kind of neat because it doesn’t take much in the way of equipment and it roasts just enough for a big pot of coffee.

The weak point in the popper method is the cooling. The beans keep roasting as long as they are still hot, so many of the sites suggest pouring the beans back and forth between a couple of metal colanders until they cool down. We tried it, and while it did cool them faster than a cookie sheet, it was more tedious than fun. It also seemed a bit silly to use this nice semi-automatic roaster and then turn it over to a manual process for the next few minutes. So, here is our better (if somewhat obvious) solution: a dedicated coffee cooling tower, built from a second modified air popper.

Interactive LED Dining Table

This is our dining table. We built it because we needed a new dining table, and I guess we’re just that kind of people. It has a frosted glass top lit by 448 multicolored LEDs that respond, in a complex and gentle fashion, to input generated by motion above the table while we eat.

We showed it off at the [link: 20060621144015830]. Click on the photo to get to see some other photos of the table construction. Lenore was interviewed about the table at the faire, see [link:LenoreCNET].

DIY Fever: Heading to Maker Faire

See us at Maker Faire! It’s a busy week at the labs here. We’re getting ready for Maker Faire this weekend in San Mateo, CA– the biggest, baddest, and most awesomest DIY festival of the year.

We’ll be showcasing an updated version of our mechanical Pong game. We’ve added a curved playing field, new user-friendly knobs, and a host of other improvements that we’ll plan to write about at a later date. We hope you’ll come by and try it out–we’ll be on the west side of the Expo hall.

Tabletop Pong - 92

Some of the other projects that we’ve taken to Maker Faire in the last few years include our Interactive LED Dining Table, CandyFab, Bristlebots, Interactive LED Coffee Table, Peggy 2, and Meggy Jr RGB.

We’re also participating in the Open Source Hardware Panel, on Saturday at 1 pm at the Innovation Stage at the south end of the Expo Hall.

Eggbot kit - preview 1

We’ll have much more to say about this later, but we’re thrilled to announce our new collaboration with
Bruce Shapiro, Ben Trombley, and Brian Schmalz. While we’re demonstrating the Tabletop-Pong game, Bruce and friends will be giving a sneak peek at the results of our collaboration: a fantastic new version of the Eggbot kit, which we are preparing for release as an open source kit sometime this summer.

Eggbot kit - preview 2

You can sign up here for more info about the kit, and you can try out the Eggbots– or just see them in action –in the center of the Expo Hall.

Lastly, to help get everyone else in the DIY mood, we’re having a DIY Fever sale over at the store, with 20% off of Evil Mad Science open-source kit favorites such as the Larson Scanner, Meggy Jr RGB and the Bulbdial Clock, and 10% off of everything else!

Happy hacking, and we’ll hope to see you all at the Faire!

Evil Mad Scientist Laboratories and CandyFab at MakerFaire!

Maker Faire.
Attention SF Bay Area folks: Evil Mad Scientist Laboratories and CandyFab are coming to Maker Faire! Space-time coordinates: San Mateo, CA, May 3-4, 2008.

We’ll be there in force with (amongst other things) a tabletop BristleBot Arena and great progress to show off on a lot of our upcoming projects: Next generation interactive LED coffee table panels, the debut of Peggy 2.0, and the brand new design for the CandyFab 5000, all of which we’ll be writing much more about this summer. Find us in the south hall, past the Tesla coils.

Great things are coming to Maker Faire, and you can come visit, get a sneak preview and chat.


We’ll sure hope to see you there. Advance tickets are on sale at a discount through Friday April 25.

Last minute Evil Mad Shopping and Projects

Lit up segments spell out the letter M

Segments visible

Time to make some LED Micro-Readerboards as ornaments for your tree this year? Watch the short video introduction to see what they do: display a message one character at a time.

This is one of the open-source holiday electronics projects that we released last year. Our up-to-date build instruction are here, including source code. We also have an FAQ about this project, a page of technical data about it, and a discussion forum if you need help with it. The version 2.0 kits (which are still available at the Make Store) use a seriously awesome ultra-high brightness, deep red 16-segment alphanumeric display for long battery life.

As of today, you can also buy the LED displays alone– just the thing for your own custom microcontroller project, alphapov display, name tag, or ornament.

[Product Page]

Jellybean versus the mechanical mouse

Next, the Interactive LED Panel Kits (as seen in the interactive LED coffee tables that we designed with Because We Can) now come with these beautiful black printed circuit boards. Pictured above, JellyBean combats a mechanical mouse on a table made with a special-order kit that has all green LEDs.

Quite a few of these tables have now been built and there’s even a new instructable from Deadly Computer about the process of building one. During the past month we’ve slowly caught up with the huge waiting list to get a kit, so it’s much easier to get one now. We have even made up some extras of the most popular kit combinations (8 panel with all blue LEDs or blue + white LEDs), which are available in stock to buy right now, shipped to arrive before Christmas to US addresses.

[Product Page]


Finally, we have some new multipurpose stickers for sale. Quite possibly the best gift in the world for the software developer in your life.

“These handy stickers will increase the visual appeal of many different items. If you happen to take them to any big box electronics stores, please bring your camera and post pictures in the Evil Mad Science Auxiliary.” We’re waiting for those action shots.

[Product Page]