The final project we worked on for Tangible Interaction was a redesign and production of a large number of their Zygote interactive LED globe concept. The globes are about six feet across, translucent, filled with helium, and contain LEDs that light the sphere in different colors as they slowly bounce across a crowd.
Tangible Interaction has built these before, but they wanted to build a new design from scratch and add several important features. They contacted macetech to work on the design and production of the new Zygote cores.
This ended up being a very intense project. We had a solid idea how to proceed at the beginning of the project, but due to worldwide semiconductor shortages, necessary parts were dropping out of stock as fast as they were specified. Every time a part became unavailable, it caused a cascade of design changes that required changing other components, which then became unavailable...and so on. Some parts of the project were completely redesigned several times.
Submitted by Garrett on Mon, 03/01/2010 - 12:38.
This year we were fortunate to play some part in a number of LED installations at the Vancouver Winter Olympics. In some cases we provided existing macetech products, and in others we developed and produced custom hardware. All the projects were developed and implemented by Tangible Interaction, located in Vancouver, Canada.
Vancouver Public Library - Seed of TruceVisit Tangible Interaction's Seed of Truce page
This was a completely custom project that had a very short leadtime. Alex Beim from Tangible Interaction contacted us about the project idea, and in less than a week they were in production (while working on other projects for Alex and holding down our day jobs). Alex needed a device that would light up an LED with a specific blinking/fading pattern, and also save enough power to run for about two weeks. He needed at least 5,000 of these devices, so the cost also needed to be minimal. Another concern was light weight.
Submitted by Garrett on Sat, 02/27/2010 - 19:20.
IntroductionWaaaaaay back in 2009, we took a coffee/side table from IKEA and wired it with 81 ShiftBrite RGB modules in a 9x9 grid. We took it to Maker Faire Bay Area 2009 and showed it off to thousands of people. However, we never managed to put together some detailed documentation, beyond a few photos.
Well, we've decided to revisit the project and show a bit more of how the table is constructed, and maybe give you a few ideas for your own LED table project. Additionally, we've added macetech's new Bluetooth shield functionality and hooked it up to Twitter! By correctly formatting your tweet and including the #ledtable hashtag, you can help create an ever-changing work of art in our living room.
Control the TableSimply post a tweet including the hashtag #ledtable and use the following pixel definition format:
#ledtable 0,3,red; 1,2,green; 4,4,#FD2245;
In other words, the first two numbers are x and y coordinates (0 through 8 allowed) and then the pixel color. You can specify a color in HTML format or just use a named color from the below:
The numerical and color values must be separated by commas, and each pixel definition must be ended with a semicolon. The #ledtable hashtag can be anywhere in the tweet, and you can define as many pixels as will fit in the tweet. Whitespace and additional text is not a problem.
We've just got word that some fans helped set up a tweet generator application for the LED table. Check it out here!
Thanks to chicklets921 for creating the generator and MikeCyberMe for setting up the hosting. There have been some really cool pictures drawn on the table, but this should help make it a lot easier. Thanks!
Live StreamYou can watch the results live on UStream below (if we have the table running at the moment). Unless you want to go to Ustream's page, just click on the little ">" arrow in the lower left corner instead of the big one in the middle of the video.
Submitted by Garrett on Tue, 02/23/2010 - 00:01.
Last year I made a pair of simple Eagle CAD files that contained headers and board outlines for an Arduino shield. The idea was that you could create a new project, copy the scaffold .sch and .brd files into it, then rename them and begin designing your new shield project. There are several part libraries out there with Arduino layouts, but in order to change the board outline, text, or add/remove holes, you'd have to go into the library and edit the part. And you'd actually need to make a new part, because if you ever open a different project and update the libraries, your edited part would overwrite whatever you had before.
Anyway, I updated the Shield Scaffold to be a little more useful. The TallParts layer contains outlines of the USB connector, power connector, and ISP header. You want to avoid any pins or exposed copper in this area, otherwise you may have an accidental short. The ArduinoHoles layer contains the original hole locations and diameters on the Arduino, in case you want to duplicate those holes to mount the shield securely with screws.
When you're ready to generate Gerber files, just make sure the TallParts and ArduinoHoles layers aren't selected in any of the CAM layers.
Submitted by Garrett on Sun, 02/07/2010 - 00:36.
This is a great new project that just went live in the FSM Café on the University of California Berkeley campus. It's a floor-to-ceiling energy meter that displays a colorful stacked bar chart of power being used by various appliances within the cafe. It contains
Here's a video of the power meter in operation:
Submitted by Garrett on Sat, 02/06/2010 - 18:45.
Right now (the time of this article) we're the only place you can buy these modules in small quantities and without an 18 to 22 week leadtime.
We currently have a surplus of TLC5947DAP chips, purchased for a series of upcoming new products. Due to worldwide semiconductor shortages, this particular chip has been nearly impossible to buy for more than half a year. We finally saw a roll of 2,000 appear on Arrow's website, and it could only be sold as a complete reel. Since there was really no other way to get the quantity we needed, we decided to buy the whole reel and then make half of it available as a service to the general (electronics hobbyist) public.
The TLC5947DAP (datasheet) is a powerful LED controller chip from Texas Instruments. It has 24 channels of individually-settable 12-bit PWM, each switching a current-controlled sink driver. The maximum current is set by a single external resistor for the whole chip. This makes the chip perfect for driving 24 LEDs with precise brightness control; ideal for controlling 8 RGB LEDs. The current sinks eliminate the need for external resistors for each LED, with correct supply voltage and heatsinking.
Check it out in our store: TLC5947
Submitted by Garrett on Wed, 02/03/2010 - 23:50.
It's been a while since my last post...we've been really busy with some projects the past few months. However, on New Year's Eve I took a couple hours to build a miniature version of the Times Square ball. I did something similar last year, with 32 ShiftBrites and a geometric drinking straw construction. This year I used a lot of plastic cups glued into a sphere, and six Satellite Modules controlled by ShiftBars and an Arduino.
There are some more photos and a video available on the 2010 New Year's ball Flickr set.
Submitted by Garrett on Fri, 01/01/2010 - 18:10.
Jason was talking to one of our distributors recently (Paul at Pololu.com). He mentioned that he wasn't going to be at home this year to try putting some ShiftBrites in pumpkins. That sounded like such a good idea, we decided to run with it!
We had a bunch of high brightness LED arrays left over from a recent project, and decided to use those to replace the candles in some pumpkins. Each array has 10 five-chip 100mA LEDs: four red, three green, and three blue. The extra red LED was added because they tend to be a little dimmer than the blue and green LEDs. Since the ShiftBar can't control more than 150mA per channel, the LEDs are arranged in series for a higher forward voltage, to approach 4.5W total. The light output is about the same as 15 ShiftBrites, with 5 extra ShiftBrites thrown in for the red channel.
Naturally, we had to start with some pumpkins. I got eight of them from Safeway and set them up in the back yard. Our friends Ethan and Karly were coming over for a barbecue, so we added pumpkin carving to the list of activities. They were happy to help carve pumpkins...and also brought food and grilled it for us! The bison burgers were delicious. The pumpkin carving went as usual...disgusting pumpkin guts clinging to everything, etc.
Submitted by Garrett on Sun, 10/18/2009 - 02:29.
Here's a great video I found on YouTube. A 2009 graduate installed 64 RGB LEDs and 8 TLC5947 drivers along with an Arduino Mini, in a mortar board cap. I don't know the actual dimensions of a typical cap, but 8" per side seems about right. The project in this video could be easily duplicated by using OctoBrites, which are 4" modules containing 8 RGB LEDs spaced 1/2" apart. Cool stuff!
Submitted by Garrett on Mon, 06/29/2009 - 16:14.
Update: I have been working on documentation; a much more complete version is available here: http://docs.macetech.com/doku.php/shiftbrite
ShiftBrites (and other LED products) are available in the macetech store: http://www.macetech.com/store/
ShiftBrites have been available for a while, and I haven't created an actual datasheet or hook-up diagram yet. I still need to do that, but this should at least provide enough information to understand what the ShiftBrite is doing, and how to control it.
A ShiftBrite has an RGB LED and a small controller chip, the Allegro A6281. The A6281 provides 10-bit PWM and 7-bit current control for each of the red, green, and blue LEDs.
The V+ and GND pins power both the LED and the control chip. ShiftBrites require up to 60mA per module when all LEDs are active. The supply voltage should be kept between 5.5 and 9 volts. I have had good results with 6V and 7.5V power supplies.
The DI (Data In) pin carries the actual control information into the ShiftBrite. It is the input to an internal 32-bit shift register. Every time data is shifted into the controller, the binary value on the DI pin is placed in Bit 0 of the shift register, and the value in Bit 31 overflows out the DO (Data Out) pin to the next ShiftBrite in the chain. Data is shifted in using MSB (most significant bit first).
Submitted by Garrett on Tue, 06/02/2009 - 00:43.