Maker Faire Bay Area 2012 Countdown Timer

Great news! The Call for Makers has been launched for Maker Faire Bay Area 2012. We're excited and apprehensive at the same time...the days seem to melt away in the months before Maker Faire. The Maker Faire site has a nice countdown timer, and we wanted to duplicate that so we could always keep an eye on the dwindling time. So we did style! Check out the video below:

A big Betabrite LED sign (scored from Silicon Valley Electronics Flea Market) receives serial data from an Arduino. The Arduino is keeping track of the difference in time between now and 10:00 AM on May 19th, 2012. Since the Arduino by itself would quickly drift into the meaningless voids of time, we have a ChronoDot installed to keep everything precise. The very handy Time Library by Michael Margolis works as-is with the ChronoDot, and also provides some handy data structures to help do the necessary math.

Here are a few technical details:

The ChronoDot is wired to the Arduino on the following pins:

  • Arduino GND to ChronoDot GND
  • Arduino 5V to ChronoDot VCC
  • Arduino Analog 4 to ChronoDot SDA
  • Arduino Analog 5 to ChronoDot SCL

No pull-up resistors were installed since the Arduino Wire library already enables the internal pullups, which are OK for such a short I2C bus.

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Submitted by Garrett on Fri, 02/10/2012 - 02:56.

Homemade New Year's Eve LED Ball Drops

(This article was supposed to be written a lot earlier, but food poisoning had a discouraging effect on the author.)

Every New Year's Eve, up to a million visitors crowd Times Square NYC to see a massive crystal and LED ball descend at the stroke of midnight. The ball has grown increasingly large and complex over the past few years, now 12 feet in diameter and over 32,000 LEDs. While an impressive sight, it's not easy to drop by Times Square when you live on the West Coast. And seeing the ball drop on TV, 3 hours early, just isn't the same. So why not build your own LED ball?

Dropping our own LED ball is a 4-year macetech LLC tradition (well, four drops, and three elapsed years to be precise). The first ShiftBrite LED Modules were produced in early 2008. By the end of 2008, we were doing higher volume production and had founded a new company, macetech LLC. ShiftBrites are a small PCB with an RGB LED and a PWM controller, capable of 1023 levels of brightness for each of the red, green, and blue channels. They can be chained together with 6-pin cables, and sent color commands by a microcontroller. Only 4 data pins are needed to fully control up to 255 pixels in a single chain.

NYE Ball 2008/2009

The first ball was a spur of the moment idea during Christmas vacation. I happened to have a "stellated icosahedron" made from a bunch of drinking straws (it was something to do between interviews during a few months of unemployment in 2006). A stellated icosahedron has 32 intersections where ShiftBrites could be placed...coincidentally, I had a bunch of used ShiftBrites that had been sitting out in the rain for a Christmas light display on our front fence. I had seen an article about the new six-foot, LED and crystal New Year's Eve ball, and decided to give it a try. A few minutes, an Arduino, and some zip ties later, and the ball was ready. We made a 20 foot pole out of electrical conduit, a pulley, and some light rope. Unfortunately no video of the actual drop, but the neighbors all came out to celebrate!

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Submitted by Garrett on Fri, 12/30/2011 - 03:17.

mtAtmo: Insanely Bright 60W LED Backlight for a 58" Plasma Screen

Ever since Philips released their Ambilight enabled televisions, hackers around the world have gone "ooooh, cool" and then immediately "how can I build that?"

If you're not familiar with the concept, it's basically a light source that surrounds a display screen. It's not a new idea...many very old televisions had a white "halo" around the screen both to make the screen seem bigger, and to reduce eyestrain. Flat panel televisions are usually mounted on or near a wall, so the idea of putting a glow on the surrounding wall was born. Philips improved on the idea by building a processor into their TVs that analyzes the signal and adjusts a ring of LEDs to match colors. Supposedly this increases immersion and reduces eyestrain...but we all know it just looks really cool.

DIY Ambilight-style setups have been around for years. One of the more popular video viewing programs, VLC, even ships with a plugin to control external LED hardware. Many purpose-built devices and DIY designs exist too. But you can use general-purpose controllers, like an Arduino, with general-purpose LED modules. Here are a few easy to build projects (some of which are pretty recent):  Read more»

Submitted by Garrett on Tue, 10/25/2011 - 22:21.

Viking Helmet with OctoBrite Fiber Optic RGB LED Mohawk

A friend sprung this project on us at nearly the last minute...he wanted a light-up mohawk on his Viking helmet. Fortunately he already had the helmet, and we already had plenty of LEDs and raw materials.


The main obstacle turned out to be the fiber optics. We discussed several options; it's pretty easy to locate bulk art-grade fiber optic spools, but cutting a few thousand fibers didn't sound like a feasible task considering less than a week remaining (plus lots of other tasks demanding spare time after work). And we had no way to easily tell how stiff the fiber was, or if it would try to curl up.

I remembered seeing street vendors selling light-up wands with fiber optics. They proved to be a cheap source of premade fiber bundles of the correct length and stiffness, already clamped into a handy ferrule. I didn't have time to hunt down a street vendor, so found a source of cheap bulk wands at The price for just the optics was acceptable, not even counting the rest of the handle, batteries, LEDs, etc.

This needed to be compact, and the helmet needed to be audio reactive too, so I also grabbed some parts from Sparkfun: Arduino Pro Mini, Electret Mic Breakout, and MSGEQ7 Spectrum Analyzer. Also needed a tiny case and some battery holders, got those from Jameco.

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Submitted by Garrett on Wed, 08/31/2011 - 18:27.

Maker Faire Bay Area 2011

macetech at Maker Faire

It's been a week since the latest Maker Faire in San Mateo. We're still recovering from the effort of putting together our project, talking to thousands of curious Maker Faire visitors, and meeting all the famous (well, maker-famous) people we usually only see on the internet.

As always, the weeks leading up to Maker Faire were a frenzy of activity. For some reason, at macetech we have an aversion to bringing the same major project twice. We'll re-use some of the smaller ones, if they're still around, but the big project always has to be built from scratch and nothing like last year's project.


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Submitted by Garrett on Sat, 05/28/2011 - 17:08.

Know Processing? Please help us with Maker Faire!

Only ten days to Maker Faire as I am writing this! That's why I need your help. Well...I need your help if you like hacking around in Processing, making neat looking graphical effects.

Our major project for Maker Faire this year is an overhead matrix of Chinese lanterns, lit by new versions of our Satellite Modules and a new controller. There will be 128 lanterns laid out in a 16x8 matrix, inside a 20x10 foot canopy. The lanterns will react to music and we'll let the audience select visualizations and hopefully interact in other ways. It's going to look awesome!

However, we're really busy just building the thing. I've gotten the LED code working well, and have tested up to 25 frames per second streaming pixel colors from Processing to an Arduino to control everything, but coming up with neat effects takes more time than we have. Here's one I have made so far:

Therefore...I'm hoping that a few helpful Processing dabblers could download my existing code and try making some new effects. I've wrapped it all up in a matrix simulator as you can see in the Youtube video. Simply draw the effect in the upper 320x160 area, and it will be pixelized in the bottom half. The pixelized area is what will be sent to the LEDs, so I need effects that look good in the pixel area too. I have FFT and beat detection all set up, you just need to hook your ideas into that. Stuff with bright colors, simple shapes, and computationally forgiving will work best. Easy!

Download Processing 1.5:
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Submitted by Garrett on Wed, 05/11/2011 - 18:07.

Simple automatic kitchen sink light

PROBLEM: Even when both ceiling lights are on in the kitchen, the sink has always been too dark at night. Anyone standing at the sink creates a shadow from the ceiling light, making it tough to properly wash dishes or vegetables.

SOLUTION: Install a light above the sink.

BONUS ROUND: Build the light from parts I already had, and make it automatically turn itself on and off.

I decided to build it using stuff from around the house. Of course, this isn't just any house...this is a geek house! So the components below were naturally considered household items. I decided to use an ATtiny84 as the heart of the project. It's way under-utilized here, but I didn't have any ATtiny25s in stock. I could have used a 555 instead of a microcontroller, but then I wouldn't have gotten a cool fade-in and fade-out PWM effect. Plus the 555 at one minute or higher time scales is a little ungainly, with the high value capacitor required. And I REALLY wanted a smooth fade-in. I would have also needed to invert the trigger signal from the PIR sensor.

Parts list:

  • PIR Motion Sensor
  • ATtiny84
  • 16 100mA white 10mm LEDs
  • LM340T-5.0 regulator
  • IRF612 MOSFET (not ideal, but works)
  • Old RadioShack proto board (do they even still sell those?)
  • 10uF capacitor
  • 0.1uF capacitor
  • 4 39ohm resistors
  • ~15V DC power supply
  • Wire and solder
  • Poster board
  • Zip ties

The schematic:  Read more»

Submitted by Garrett on Sat, 03/05/2011 - 23:23.

Emergency Fake Moon

A friend was having birthday party late yesterday, to coincide with viewing the total lunar eclipse. That evening I realized there was quite a lot of cloud cover, and it was cold outside. I decided to build a moon simulator so that we could keep an eye on the eclipse regardless of the weather.

Lunar eclipse simulator  Read more»

Submitted by Garrett on Tue, 12/21/2010 - 18:09.

RGB Pixel Tree

We got our Christmas project done a bit later than usual this year, but here it is. An eight-foot wooden triangle filled with 51 MegaBrite RGB LED modules, controlled by an Arduino. As our projects always do...this also lights the houses across the street pretty well, running about 75 watts of LEDs maximum.

Unfortunately didn't take photos during construction, but it's nothing too difficult. Three 1x4 planks fastened at the corners with metal brackets, 3/4 square dowel cross beams, and lots of zip ties. The MegaBrites are daisy chained from a bottom corner up to the top in a zig-zag pattern. Power is connected every 7 or 8 modules, to a 7.5V 20A Meanwell supply from Jameco. For rain protection and a little diffusion, the whole thing is wrapped in a 2mil plastic drop cloth.

Submitted by Garrett on Sat, 12/18/2010 - 22:51.

Giant magnet - with sparks

Was running out of ideas for a Halloween costume, and fell back on the old standby "Mad Scientist". I mean, I have all the stuff already :) The sad part is for the past couple years I've spent so much time working on a really awesome costume, I didn't actually go anywhere! Two great robot costumes, never to be even had an Arduino-powered voice changer. *Maybe* this year will be different, assuming I don't think of some last minute enhancement that takes another week.

So I had the lab coat and magnet already. The idea was to hang out next to the line for the Insane Clown Posse when they had a concert in town, around the time of the whole "Miracles" meme. I built the giant magnet out of two layers of 2" styrofoam insulation panel from Home Depot. Did not have a hot wire foam cutter, so I made one by running about 20 amps through a piece of 28 gauge magnet wire.

So I wanted to use the magnet for the mad scientist costume this weekend, but thought it needed a little more pizazz. Also, some bracing across the ends so it wouldn't get crushed and broken. A piece of clear acrylic seemed like a good idea. Then, I realized that the acrylic could have more than just a structural function. I called up TechShop and reserved some laser time, and etched fractal lightning patterns on three panels.

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Submitted by Garrett on Sat, 10/30/2010 - 00:57.