Check out GPS glove puts digits on my digits by Andrew Smith a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Featured Adafruit Products

FLORA – Wearable electronic platform: Arduino-compatible – For the last few years Ladyada has been thinking about everything she wanted in a wearable electronics platform for Adafruit’s community of makers, hackers, crafters, artists, designers and engineers. After months of planning, designing and working with partners around the world for the best materials and accessories, we can share what we’re up to. The hardware is now shipping! We call it the FLORA. (read more)

Check out The Dogs of Late Night in 6 Seconds by insultcomicdog a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Check out bone bmp085 java & go by Carl Bredlau a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Check out Time-Lapse Rig by SeamusTheTinker a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Check out yet another (binary) clock by Carl Bredlau a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Check out Tiny 3x3x3 LED Green Cube TinyDuino by thithathu a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Check out scad interaction design student project by Colin Beney a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Check out Westwood Student Project 2001 by Jay Wyshak a short 6 second film for the Adafruit #adafruit6secs electronic film festival (Youtube playlist here for all the entries on YouTube).

Featured Adafruit Products

FLORA – Wearable electronic platform: Arduino-compatible – For the last few years Ladyada has been thinking about everything she wanted in a wearable electronics platform for Adafruit’s community of makers, hackers, crafters, artists, designers and engineers. After months of planning, designing and working with partners around the world for the best materials and accessories, we can share what we’re up to. The hardware is now shipping! We call it the FLORA. (read more)

Chinese DIY Inventions – In Focus – The Atlantic.

One visible sign of China’s recent economic growth is the rise in prominence of inventors and entrepreneurs. For years now, Chinese farmers, engineers, and businessmen have taken on ambitious do-it-yourself projects, constructing homemade submarines, helicopters, robots, safety equipment, weapons and much more. Some of the inventions are built out of passion, some with an eye toward profit, (some certainly safer than others), and a few have already led to sales for the inventors. Gathered here are recent photos of this DIY movement across China

Mjolnir at 80,000 volts

I wanted Thor’s hammer (Mjolnir), but I wasn’t going to accept any old boring plastic prop. I needed something with a little more POP.

I worked with Staci Elaan to build this hammer that has a solid state tesla coil inside. When you push the button, 80,000 volts of electricity arc from the top.

It will light up any flourescent bulbs around, scare children, and leave the smell of ozone behind. It is super fun!

Read more!

Cool headphones that use a repurposed SNES controller via Hackaday:

Here’s a build that just exudes nerd cred. It’s an SNES controller modified into a pair of headphones, straight from the workshop of [lyberty5].

The build began by stealing a controller from a PAL SNES and carefully dremeling the buttons and d-pad loose from their plastic frame. The PCB was cut in half, and the remaining plastic was carefully crafted into round speaker enclosures with the help of some epoxy. hot glue, and possibly a few pieces of styrene.

Photos and more here!

I spent the entire last month designing and building these LED lights for Ra Ra Riot’s US tour, check out some videos and build photos here! Uses nearly 125 meters of our Digital Addressable LED strips

The set up consists of 12 LED poles, 3 LED boxes, and 8 DMX colorblast fixtures. LEDs are mounted behind frosted acrylic to diffuse the light evenly.
Each unit is operating from it’s own dedicated Arduino. At the helm of the Arduinos is an Adafruit FTDI Friend that communicates one way to all 16 at once. Each Arduino has its own internal address and receives 14 byte packets of data telling it what to do (rate, pattern, color, brightness).
All patterns are baked into the Arduino code- that way if there’s ever a serial disconnect, the lights will continue to run. In addition to the pattern data, the computer sends a heartbeat 10 times a second, insuring they stay in sync for patterns like color fading and strobing.
A processing sketch running on the computer controls everything, and is extended further to use an iPad for wireless control via touchOSC and oscP5. We are working on an update for a Lemur sketch to offer even more control.

Read more.

Uncle Sam Wants You! Now’s your chance to change the way our country does medical simulation and battlefield care. The 2013 microMedic National Contest is calling the best and brightest, that’s you, to help invent new medical applications using microcontrollers. With over $25,000 in cash and prizes awarded to the winners, what are you waiting for? Contestants may use any microcontroller they desire in their application. Parallax is offering two flavors of the microMedic Application Idea Kit full of tons of sensors and cool parts; one kit has the multi-core Propeller chip, the other includes the Board of Education Shield (for Arduino).

In order to help you in your quest we’ve created a special discussion forum for the microMedic contest, provided a list of project ideas and created a bunch of mini-tutorials to help you get started with the kit sensors. We’re even giving away 100 free kits to the first qualified entries. This contest is open to participants of all ages with special prizes for educational and public division winners.

Hurry, contest ends July 31st, 2013! For all the info on the contest check out http://learn.parallax.com/micromedic. Be sure to visit the Official Rules page for all the details on contest entry, including how to apply for a free kit.

Good luck from Parallax, the U.S. Army and Carnegie Mellon University!

Best Technology Projects of 2012. Randy @ Instructables write -

Before the world comes to an abrupt end, I thought it would be pertinent to look back on the last year, and highlight some of my favorite Tech Instructables. Initially, I was going to make this a top 20 list, but with over 5,600 Technology projects to choose from, had trouble narrowing it down. After much mental gymnastics, I managed to narrow it down to a respectably-sized list of 30 great projects. I present to you now – in no particular order – my list of highlights for 2012.

Full list!

I wanted to thank you for the work you do to provide tutorials and libraries for your items. It allowed me, someone with minimal programming and electronics knowledge, to setup a full featured data logger for my recent weather balloon project. Checkout the youtube video below (data from my logger charted at the end of the video). Thanks again, keep up the great work and I’ll keep telling my friends! -Dustin

We’d say you earned this skill badge for sure! high-alt balloon badge

Altoids Projects via Dangerousprototypes. A Norwegian radio amateur (LA3ZA) writes…

I like to build small electronics projects and like many others I have found the small Altoids tins to be excellent enclosures. 

These tins are inexpensive, well shielded, easy to work with, and least but not least they enable you to make experimental circuits that are sturdy enough that they can be reused later.

Pictured here is a collection of projects I have built over the years with the hope that  they may inspire others.

Active Pickguard by Eli Hughes.

DIY Resistor Substitution Decade Box. George (our video producer!) writes -

Here’s a handy guild on how to build your own DIY Resistor Substitution Decade Box. I had seen several people online building their own, but instructions weren’t very clear.  Hopefully these 50 or so pictures will help. First step – hop onto ebay, and pick up some switches.  You can find them by searching for “decimal thumbwheel switch”  – I think I only paid $5 for 10 of them including shipping (from china).  Order up some extras – they can be used for all sorts of things – and a fun part to keep around.

Super Angry Birds – a Tangible Controller {+ hack} at { sound + design } thanks Jeremy.

We hacked a motorized fader found in audio mixing consoles to create the force feedback. If you are interested, you can read the paper. Basically, the way we achieved this is by drawing a force curve and storing the values in a table, then we send the current position of the slider through the table and extract the value to send to the motor that applies an opposing force. You can check this in action in the “How it Works” part of the video.

We programmed in Max/MSP and Arduino. For controlling the hardware, we used an Arduino-based microcontroller called Music & Motors… developed by CIID.

This project was made by Hideaki Matsui and I (Andrew Spitz) in a class on Haptics at CIID run by Bill Verplank and David Gauthier.

Artemis Synthesizer: A Music Synthesizer Kit. Chris writes in -

Hello Adafruit!

I just finished my writeup for my Music Synthesizer kit project. The kit was made for a soldering workshop for the Boston University Artemis Project (http://www.bu.edu/lernet/artemis/), which is a Women In Technology Summer Program for rising high school freshmen. I work for the BU EDF (edf.bu.edu), which normally makes electronics for physics experiments, but we also do outreach electronics programs.

Normally the workshop would have contained a POV light toy, but we wanted a change of pace and I took lead to develop a music synthesizer with an 8 button keyboard, which can also act as a sequencer. There is a phototransistor which can pick up a light based message generated by this page, which my coworker Sam Damask made
(http://edf.bu.edu/~swd/javascript/sine_wave_audio_jq2.html), to program in sequences and new waveforms.

Video & writeup. Design Files and Firmware: github.com/cwoodall/artemis-synth-v1

Much of the hardware design for the DAC to Amplifier Interface was referenced from the Wave Shield; however, I made a bunch of changes to suit my particular situation and goals!

Getting the big question right out of the way: no, we won’t be selling these. Legally, we can’t, for trademark reasons. But it’s generally okay for anyone to create replica props for their own personal use, so we hope this writeup will inspire some cool projects among our readers…

From the moment these LED displays made an appearance on our weekly Ask an Engineer show, comparisons were being made to the DeLorean time circuit from the Back to the Future films. It was a moral imperative then to make a demo! If you’re handy with Arduino and some shop tools, you should be able to pull off something similar (better, even), or adapt the ideas to other projects. This was quickly built in fun, so please don’t expect the same level of polish as a finished product tutorial.

Taking Some Liberties

When accepting this assignment, I might’ve failed to mention a small detail: I don’t own a car, let alone a DeLorean, for displaying the finished prop. Instead, mostly inspired by Jeri Ellsworth’s NES purse, I had this goofball idea of a slim, battery-powered device that could be placed in ironic settings: on a bicycle, on public transit, hung from a Flavor Flav necklace, and so forth.

While the general idea could have been accomplished quickly and easily with an iPad running the Flux Capacitor™ app, I wanted to preserve somewhat the staggered design of the original, and it had to have real 7-segment LED displays…there’s no substitute for seeing the genuine thing. In much the way that nixie tubes have a certain vintage coolness about them, LED displays too are reaching a nostalgic threshold, iconic of 1980s technology.

Using stock parts required some design compromises. The date and time formats would be changed to fit these 4-digit displays (the film prop used back-painted glass fakes for the month display, with some segment changes being physically impossible, making a 100% match unattainable anyway…iPad wins there). Also took liberties with some LED colors and various spacings, but overall the piece is still highly recognizable.

For the sake of a quick demo, I had to cut this short. Though all the displays are addressable, the destination and last-departed dates are simply fixed values from the first film; there’s no interaction. I may revisit this to add a keypad later, but for now it’s all just a fancy clock (it does show the current time accurately, using a ChronoDot RTC). Also, the vector files are not available, because they’re utter garbage! Creating something of finished kit quality requires many iterations and refinements…but with a rushed, one-shot piece like this, course corrections would come in the form of a Dremel tool and epoxy putty. If you plan to build one, give it some time and prepare your blueprint carefully.

Number Problems

These 4-digit displays can be assigned one of eight fixed I2C addresses via solder jumpers on the back. But the time circuit needs nine displays. A few possibilities were considered, including driving the one extra display “manually” with shift registers, or use a software I2C library and split the displays among multiple I2C buses. Either would require lots of library code changes and some intense concentration, but I was hit with a massive sinus headache at the time and really didn’t want to think about it.

Instead, exploiting the fact that we need just one way, write-only access to use the displays, I used a simple hardware hack to split the I2C bus to communicate with one row of three displays at a time (saving some code by repeating the same addresses in each row). The I2C data line fans out to all the displays as normal, but the clock feeds the enable lines of a 74HC138 3-to-8 line decoder, and the microcontroller can then select which output line forwards the clock signal. The data on the other I2C buses is ignored without the corresponding clock.

To keep this ultra slim, a Teensy microcontroller board was used — a standard Arduino wouldn’t fit, not even the headerless Leonardo. After prototyping the full circuit on a breadboard, all the parts were soldered point-to-point and “dead bug” style inside the case. Power is provided by three AA cells in series — a bit under the ideal 5 Volts, but still sufficient to run everything. The cells fit in the “chin” below the three dates. I’d mail-ordered a special battery holder for this, and then in my rush to complete the project I went ahead and made all the case parts based on the holder dimensions on a web site. Naturally then, with the case already cut and glued, the part that arrived was slightly larger than the dimensions posted. The fix was to break off the battery contacts from the ends of the holder and epoxy putty them directly into the case. This eliminated just enough girth for everything to fit. The remaining electronics were delicately folded into the case with copious amounts of hot-melt glue, tape and swearing.

The case was fabricated from laser-cut acrylic and sprayed with faux hammered metal paint. A metal enclosure would have been more authentic (and more work), but a corollary to “Maslow’s hammer” dictates that when you have a laser cutter, every project appears ideally suited to acrylic. The labels were inkjet printed and made into stickers with a Xyron applicator, trimmed with an X-Acto knife, then painstakingly touched up with a Sharpie marker to hide the white edges. After the labels were applied, the bezels received a thick spray of acrylic sealer, then attached to the front of the case with epoxy.

Go for it! If you don’t own a DeLorean, this will still impress your co-workers and look great on your desk. Or maybe you can devise a scheme around Halloween or a geek-fest like Dragon*Con. Bolt it just below the arc reactor on your Iron Man suit (you do have an Iron Man suit, right?). Or if you have a young son in a stroller, attach the time circuit to the tray, dress junior in mirrored shades and a life preserver down vest, while dad dons a Doc Brown getup. Instant father-son cloying adorableness!

Even if you don’t build this exact item, if it inspires any nifty electronics projects (*cough*Proton Pack*cough*), please share them in the forums, bring them to the Saturday night show-and-tell or document your build on a site like Instructables. Customer projects are frequently showcased on the Adafruit blog!

Resources

Here’s the Arduino sketch that runs the show.

Parts from the Adafruit store include:

• Teensy (ATmega32u4 USB dev board)
• ChronoDot Ultra-precise Real Time Clock
• 0.56″ 4-Digit 7-Segment Display w/I2C Backpack – Red
• 0.56″ 4-Digit 7-Segment Display w/I2C Backpack – Green
• 0.56″ 4-Digit 7-Segment Display w/I2C Backpack – Yellow
• Diffused Red 3mm LED (note: film prop used yellow LEDs on destination time)
• Diffused Green 3mm LED

Additional parts acquired from Digi-Key include:

Fermentation Thermostat Project – “Ohm Brew” via the Adafruit customer support forums. ruprect writes -

Good afternoon all. I wanted to show you guys my project and possibly get some feedback. I home brew beer and, during the (Texas) summer, I have a problem keeping my house at a temperature that is within the ideal conditions required for the yeast to thrive during the fermentation process. So a common solution to this is to create a fermentation chamber to allow your beer to ferment in a controlled environment. Many people use a chest freezer with an additional thermostat for this. There are a couple non-programmable thermostats available that work very well.

However, when brewing a lager-type beer, a more complex temperature profile is required for ideal fermenting conditions. For instance, a typical lager fermentation could be: Lower the temperature from 76 to 52 degrees over a period of 24 hours, hold temp at 52 for 10 days. Slowly raise temperature to 68 degrees over a period of 24-48 hours, then lower the temp to 34 degrees over a period of 48 hours and then keep it at 34 for 6 weeks.

This sequence of temperature is a lot of work and dedication (especially for someone with as short of an attention span as myself) for a manual thermostat. So I have created a programmable thermostat to control my fermentation chamber. I created it with a PIC18F microcontroller, a TMP36 temperature reading IC, and a relay. I created a user interface with the help of a 16×2 character LCD and an up/down/select keypad arrangement.

I have a ‘Default Lager’ program built into the thermostat (not surprisingly, very similar to the one described above), but I also added a function to be able to create your own temperature profile or edit a currently saved one.

I have added functionality for the user to navigate through the program to any stage/time the user wants.

I’ve just finished up with this, I am currently testing it out and working out a few little bugs here and there, but I hope to be able to put this to work very soon. Being able to brew lager-type beers opens up a whole new set of beer recipes to brew (and drink! )

We’re awarding this maker a “brewing badge!”

Can’t wait to see this project at the Maker Faire this weekend!

This is my Maker Faire Bay Area 2012 project, the Arduino GRANDE. It is a fully functional Arduino that is about six times larger than real life. Come hear all about it at the Maker Faire this coming weekend, May 19th and 20th. I’ll be doing talks and demos on Saturday. http://makerfaire.com/pub/e/8185

It’s easy to add EL wire to furniture! Welted EL wire is great for applying with a stapler while standard EL wire makes great upholstery piping. Learn both techniques, as well as soldering to make easy-connect sections (if your couch is a sectional). Video on YouTube and Vimeo.

For this couch I used:

• High Brightness Aqua Electroluminescent (EL) Wire – 2.5 meters
• Sewable Electroluminscent (EL) Wire Welted Piping- Aqua 5 meters
• In-line wire 1-to-4 splitter
• In-line power wire connector (female)
• In-line power wire connector (male)
• 12V EL wire/tape inverter
• 12V 5A switching power supply
• Female DC Power adapter
• copper tape (found in one of our starter packs)

While I don’t recommend sewing the welted EL wire by hand, it would make great pillow piping on a sewing machine project, and staples like a dream.

If you liked this tutorial, also check out our EL wire TRON-inspired bag project.

It’s really easy to change the output of the Internet of Things Printer– the Twitter query is just one line of code you modify in the Arduino sketch. In this video I show you how to reprogram the IoTP to print Jenny Holzer aphorisms directly on my desk (although yes, I realize the twitter account isn’t run by Holzer herself).

The Internet of Things Printer is open source: you can read the tutorial, download the code and enclosure laser files, and please share your own versions with us in the Adafruit Flickr pool!

NEW PRODUCT – Adafruit IoT Printer Project Pack “Internet of Things” printer. Build an “Internet of Things” connected mini printer that will do your bidding! This is a fun weekend project that comes with a beautiful laser cut case. Once assembled, the little printer connects to Ethernet to get Internet data for printing onto 2 1/4″ wide receipt paper. The example sketch we’ve written will connect to Twitter’s search API and retrieve and print tweets according to your requests: you can have it print out tweets from a person, a hashtag, mentioning a word, etc! Once you’ve gotten that working, you can of course easily adapt our sketch to customize the printer.

The project is not very difficult but does require some light soldering, so you’ll want to have a little experience with a soldering iron. You’ll also need a small flathead screwdriver to assemble the box. It’s also best if you’ve had a little Arduino experience so you can feel comfortable downloading the IDE and uploading our example sketch.

Contains:

• Mini Receipt Printer. BPA-Free
• 50 foot long receipt paper
• 5V 2A power adapter
• 2.1mm Panel Jack
• Waterproof metal On/Off button
• Extra long header piece
• Ribbon cable
• 1/8″ heat shrink
• Laser cut enclosure + hardware

This pack does not contain an Arduino+Arduino Ethernet Shield, Arduino Ethernet or Ethernet cable To complete the project you will need to add either an Arduino + Ethernet Shield or an Arduino UNO Ethernet. If you’re using an Arduino UNO Ethernet you will also need an FTDI friend or FTDI cable to upload the sketch. A plain straight-thru Ethernet cable is also required (any length)

Before purchasing, please check out the full tutorial with images, code, etc!

In stock and tweeting now!

Lucly Panda Fortune Teller @ Electric Projects.

I finally finished this project. I had previously made a much smaller version with only a LCD screen, but no printer as they were not available at the time.

First I started out getting the thermal printer to work with an Arduino and a LCD screen.

Once I had this working, I wanted to make a more permanent version.  About this time Adafruit started selling perma proto boards. These are great for soldering your project into and are very sturdy….

NEW PRODUCTS! Electroluminescent (EL) Tape/Strip Starter Packs! – 100cm – White, Green, Blue, Aqua and Red. Get glowing in seconds with our Electroluminescent (EL) Tape Starter Pack! This pack contains everything you need for your first EL tape project, even the batteries.

Includes:

• 1 meter long x 1 cm wide EL tape strip
• Portable 4xAAA inverter powerful enough to drive a full meter of strip
• 4 x AAA alkaline batteries to power the inverter and tape for 10 hours

Electroluminescent (EL) Tape/Strip Starter Packs! – 100cm – White
Electroluminescent (EL) Tape/Strip Starter Packs! – 100cm – Green
Electroluminescent (EL) Tape/Strip Starter Packs! – 100cm – Blue
Electroluminescent (EL) Tape/Strip Starter Packs! – 100cm – Aqua
Electroluminescent (EL) Tape/Strip Starter Packs! – 100cm – Red

Bryan Duxbury’s Super Mario ? Block Lamp.

Hey guys, this seems like it would be up your alley. I designed and fabricated a custom lamp based on the ubiquitous Super Mario Brothers ? blocks. The bottom is a DIY capacitive-touch sensor which triggers an LED array and a tiny speaker to play some sound effects.

The best part is that the whole thing is powered by a little ATTiny85, including all of the audio! I’m really excited about the potential to make use of those cheap little microntrollers in places where you’d normally have to sacrifice an Arduino Uno. I plan to write up the full details of the build at some point, but for now you can just enjoy the video.

DISCO! We hope you enjoyed the over-the-top X2 Time Ball video as much as we enjoyed making it! Getting this finished in time for New Year’s Eve meant the progress blog posts would have to wait, so we’ll be returning to a few details now after the fact, and continuing as future design plans are ironed out…

As explained in an earlier post, we settled on an icosahedron shape as a sanity-preserving measure. Every single LED — 120 of them — must be installed in a specific sequence, and using a higher-order polyhedron would require following a very complex map for their locations. The icosahedron is simpler with 20 identical triangular faces, and the same wiring sequence from one to the next (with alternate rows rotated 180 degrees):

This is just the installation order for the LEDs; wiring for power was also explained in a prior post. There are additional wires (not shown here) that are joined to power distribution strips only after all the LEDs are pressed into place.

The polyhedron faces were laser-cut from mirrored acrylic. To make the wiring process less error-prone, the order of connections was drawn on the back side of each face with a permanent marker (identical for every face, so this goes fairly quickly):

Pairs of faces were then joined up and are loosely joined with cable ties (there’s a specific alignment: note how the “in” and “out” wires always come and go from the sides); this produces 10 identical diamond shapes. The 10 diamonds were then laid out to match the wiring diagram above, and similarly joined with cable ties, producing a complete 2D map:

Starting from the top-left triangle and following the wiring sequence exactly, each LED pixel (beginning from the microcontroller end) is then pressed into place. This involves a lot of twisting and turning in order to avoid tangles in the wire, which is why the power leads should not be joined to anything yet (the strand needs to turn freely at one end):

Above: one triangle down, 19 to go. Below: all LEDs installed, power not yet connected:

Loosely rolling everything up into a ball at this point revealed a problem. I’d been obsessed with the idea that all of the electronics (including the microcontroller, XBee, power distribution bars and protective plastic covers — a roughly fist-sized wad of stuff) should fit inside the ball, so only a single power cable would protrude. But when folded up, the loops of wire between pixels didn’t allow enough space at the core. This required going through and doubling every loop back on itself:

The power cord would do double-duty as a means of suspending the ball. This may or may not actually be a good idea — I can’t help but imagine there’s some kind of electrical code regulation against doing this, but then IKEA lamps seem to do it all the time. So, purely as an experiment for now, an extra plastic piece locks neatly over the ferrite core at the end of the power cable. This is fed through what will be the top vertex of the polyhedron, where five triangles meet at a point. When it’s all cinched up, the cord won’t slip back out through the hole.

The flat icosahedron map is then loosely rolled up like a burrito, with more cable ties holding it in place. The bottom vertex is closed, then all of the power leads are joined to the distribution bars, the electronics package is screwed together and placed inside, and the top vertex is closed around the power cord.

Three or four passes are then made around all of the cable ties, gradually transforming the shape from a chaotic molten glop into a neatly-ordered polyhedron…albeit a bristly polyhedron at this point:

Two tools can be helpful for finishing. The first, a cable tie gun, is not essential but can really improve the final cinching down of each piece, to get every cable tie uniformly snug. The second is an ordinary nail clipper, to cut each cable tie flush (wire cutters don’t cut them quite flush, resulting in hundreds of sharp little plastic points and a disco ball that’s very painful to handle!).

The microcontroller inside had previously been programmed with the LEDstream sketch — essentially the same as used by Adalight and Adavision, with just a small change to read from the XBee module rather than the USB port. No code had been written for the ball at this point, but the Plasma demo from Adavision would at least show if the ball was receiving data. After plugging it in and firing up the code, it works!

Some ideas didn’t pan out as hoped. Remember those 5 extra LEDs from the wiring diagram? The project used five LED strands, which come in lengths of 25 pixels each (125 pixels total), while the icosahedreon needed only 120 (20 faces x 6 pixels per face). The extra five could have been trimmed off and used in some mini-project, but instead I had the idea to use these to illuminate the interior of the ball, which would then be visible through Adafruit logo-shaped cutouts at each vertex:

In practice, the internal LEDs didn’t provide uniform lighting. They tended to get smooshed up against one face or another, and would throw off the color of the outside LEDs in that specific area. So the code now leaves these LEDs turned off.

“Bronze mirror” wasn’t the best choice of materials; it tends to photograph as almost black. Future iterations will use traditional “clear” mirror.

XBee also didn’t perform as well as hoped, but that’s a post for another day. In the meantime, here’s a dinosaur holding up a disco ball:

A quiet holiday provided some much-needed time for making progress on the New Year’s disco ball — officially now titled the “X2 Time Ball.”

The discosohedron Time Ball will have 120 RGB LED pixels on its surface…that’s nearly as many as the Adavison video wall, and faced similar problems of feeding power to than many hungry LEDs (nearly 7 Amps worth!). Adavision used an ATX computer power supply…an excellent frugality hack because these power supplies are plentiful and cheap (sometimes reclaimed from old equipment). But as a “fashion item,” the Time Ball would benefit from clean cabling…not to mention that the loud fans in some ATX power supplies can be like working next to a jet engine.

Since ample power is going to be a recurring need as customers’ LED projects grow in scope and sophistication, we’ve been evaluating different options, such as this laptop-style power brick:

The brick is compact, fanless, provides 5 Volts at up to 10 Amps, uses the same 5.5/2.1mm power connector as the smaller 2 Amp supply and is compatible with the screw terminal adapter. Looks like a winner all around, so expect to see this in the store some time in the weeks ahead! (Until then, Ask an Engineer viewers know the drill: “It’s not out yet, so don’t ask.”)

A lot of devices use this same plug, including our 9V and 12V power supplies. In order to avoid expensive blue smoke and heartbreak, I’ve gotten into the habit of immediately labeling all power supplies near the tip so they don’t get mixed up with the wrong equipment. Over-voltage will kill your LEDs!

For distributing power, Adavision required soldering pairs of power wires to ATX power cables. Wanting something that could be more easily dismantled and reconfigured in future projects, I’ve been examining alternatives such as these barrier strips and jumpers:

The barrier strips are fairly common and can be found at Radio Shack, the electrical department in better-stocked hardware stores, or various online sources. Meanwhile, the 8-position jumper (which converts the barrier strip into a single “bus bar”) is seemingly milled from a single block of unobtanium or something. The only place I’ve located this elusive item so far is…drumroll for irony…Radio Shack!

Two six-position barrier strips are used, one each for +5V and ground. Terminal spades have been crimped onto the power leads for five LED strands, as well as leads for the microcontroller and heavy-gauge wire to the screw terminal adapter for the power supply. The jumper strips are cut down to size with beefy wire cutters. Plastic covers will later be added to avoid electrical shorts:

The project provided an opportunity to test something out that I’ve been eager to try. If you’ve worked with longer LED strands powered from one end, you may have observed a phenomenon where the furthest LEDs become progressively discolored, due to the voltage drop along the length of the wire. This is why I’ve been adamant about limiting strands to about 25 LEDs (or 1 meter with the LPD8806 strips) before adding additional power taps. The voltage drop on shorter strands is less noticeable.

A common work-around is to power longer strands from both ends. Generally speaking, this probably works well enough in most situations, but it does leave the door open to possible gremlins later when you least expect it. Ground loops — multiple paths to ground — could make the data signals more susceptible to interference. Everything works fine on your desk, then you set it up elsewhere — perhaps there’s an unseen microwave oven on the other side of the wall — and are up ’til 3am looking for the bug you think is in the software.

To avoid this with Adavision, strands were powered from the middle — 25 pixels to the left, 25 to the right. Limiting the strand length makes the voltage drop less obvious:

If you’ve been to the west coast Maker Faire then you may have met my friend Lindsay and his Electric Giraffe, 17 feet tall and covered head-to-toe in LEDs. Needless to say, he’s had a bit of experience with LEDs and long distances:

A simple trick he showed me is to power the strands from opposite ends: +5V at one end, ground at the other. Because the power to every LED then passes through an equal length of wire, the voltage drop is consistent. There’s still some voltage drop — you can’t change the laws of physics — but it’s uniform along the entire strand and all the LEDs are equally bright. And no ground loop:

Five such strands are used in the Time Ball. The clock and data wires are joined from each strand to the next to form a continuous 125 LED strand with five +5V and five ground wires leading to the power blocks. Only 120 of these LEDs are needed for the ball…the rest could be cut off and used in a small project, but in case a complete strand was needed later I opted to leave them attached, stuffed inside the ball and not addressed by the software.

Set your calculator to “maths”…

Yesterday two basic criteria for our New Year’s LED project were established:

1. Our “ball” will actually be an icosahedron — a 20-sided shape — for ease of assembly. Each face will have six LEDs, for 120 LEDs total.
2. To create meaningful patterns on the ball, rather than just random blinking, it’s necessary to know the coordinates of every LED. Therefore, a software model will need to approximate the physical thing.

The first step to finding the LED coordinates is to establish the positions of each of the 12 vertices of the icosahedron, even though there are no LEDs there. Once those points are known, all the LEDs can be located through interpolation.

There are a number of ways of constructing an icosahedron…the Greeks were working up the math in 400 B.C., the Scots might have hammered it out in the late Neolithic Age…though some protozoa and viruses had us all beat by half a billion years or so.

Our “ball” will hang from one vertex at the top, so we’ll follow a construction method to suit. When viewed down the vertical axis, there’s a clear 5-fold symmetry:

Starting with just the radius of those “spokes” from the center (we’ll use a value of 1.0 — the units are arbitrary), a couple formulas are all that’s needed to find the 3D position of one vertex, and from that to replicate all the remaining vertices by revolving around the center axis. Wikipedia can help with the maths!

From those vertices we can then identify edges and faces. Using two edge vectors from each face, the triangular 1-2-3 layout of the LEDs can be interpolated across this. Wrapped up in just a short Processing sketch, we now have a tumbling 3D icosahedron with LED dots in the desired places! Later, we’ll issue colors based on each LED’s location.

A test sketch for Processing is available from the project’s Github repository. This does not yet communicate with an Arduino or the LEDs; it is strictly for validating the geometry. It’s a good visual match for the model on the table!

“Simplify, simplify, simplify.” — Thoreau

“One ‘simplify’ would have sufficed.” — Emerson

With a nifty construction method settled upon, it was time to decide on a polygonal shape for our “new year’s disco ball.” This seemed like a solved problem — geodesic domes are sufficiently popular that you can find kits and calculators all over the internet — but we soon hit a snag: while at first glance these domes appear to be comprised of many identical triangles, it turns out there are actually very subtle variations throughout. This is not a technical problem at all; it could certainly be done, but it fails our Annoying Test. Each piece must be aligned with exactly the right neighbors and turned exactly the right way. Now repeat the process dozens or hundreds of times without a single mistake. No.

So, Plan B, we looked at Archimedian solids. Many of these polyhedra achieve a nice ball-like shape while being comprised of just two or three types of regular polygons. The truncated icosahedron (colloquially sometimes labeled a “soccer ball” or “Buckyball”) was especially pleasing:

On its own, the shape is now pretty easy to build. But when it came time to think about lighting this up, even this shape proved just a bit too complex. Here’s why:

If we just wanted to jam LEDs in there and blink them at random, that would be simple and we could call it done. But that’s…just…lacking something. We’d really like to be able to address these LEDs with order and purpose…top to bottom, around the circumference, you name it. And again, there’s nothing technically barring us from doing that with this shape. It’s simply a matter of not wanting to alienate readers and kit-builders with limited patience. You see, to keep track of their positions, every single LED would need to be installed in a specific place, in a specific sequence, somewhere on this map:

Not fun to try to explain…or read…in instructions. So we’ll back off one more step and consider the Platonic solids, which are each comprised of a single repeating regular polygon. Gamers are well familiar with them:

(Please ignore the d10 and imagine a d6 in its place!)

The dodecahedron (in blue) and icosahedron (red) are both vaguely round…ish. We settled on the icosahedron, comprised of 20 equilateral triangles, because the math is simpler, and it spreads out nicely as a flat map:

Much easier for indicating where will LEDs go! And a quick ugly prototype confirms that the LEDs will fit:

So, after that whole digression, we’ve come full circle to use one of the original cable-tie assembly shapes we had already looked at!

We’ll make the finished ball (yes, we’re still calling it a “ball,” despite its obvious polygonality) in mirrored acrylic for added bling factor. With 20 faces, and six LEDs per face, that’s 120 LED pixels total. We’ll need those figures later when coming up with a power supply…

In making our LED disco ball for the new year, it will be necessary to transition from the flat planes of Adalight and Adavision into the three-dimensional world. This has been a humbling experience in the KISS principle: “keep it simple, stupid!” The first tries did not end well…

Our initial attempts involved taking existing 3D forms (globes, salad bowls and lamp post diffusers, among other things) and drilling holes over the entire surface for mounting LED pixels. This is not an entirely rotten idea, but it falls short of one of our goals: we might like to offer kit packs in the future…or at the very least, readers should be able to follow along at home! Asking would-be customers to drill a precise geodesic pattern of holes into anything wouldn’t be a great PR move. (By way of comparison: you might be familiar with the Hoberman Sphere toy…but few recall the earliest version to land in stores: a bag of eleventy bajillion nearly identical plastic parts, to be assembled by the customer…or, just as likely, to be half assembled and either returned or flung in the trash in frustration. Later editions came pre-assembled, and the rest is history.)

Disco ball FAIL!

Two additional factors pushed us toward an alternate approach:

1. A kit should be easy to package and efficient to ship.
2. Laser-cut acrylic is the bee’s knees for holding LED pixels!

Adalight—ambient lighting for your monitor—was one line of LEDs, formed into a loop. Adavision—a mini LED video wall—spread out into a 2D grid. It’s only natural then to take the next step into the third dimension. Not simply a cube though…with the new year nearly upon us, and paying tribute to Adafruit’s NYC home, why not a shimmery Times Square-style “disco ball?” This would showcase the WS2801 Pixels’ greatest feature: unconstrained by flat planes or fixed grids, they can be spread out into any shape. Anything you can punch 11.5mm holes through, you can festoon with LEDs, whether it’s your backpack or the body panels of a Burning Man art car!

(Ours won’t be anywhere near this big.)

The Times Square ball drop always seemed a bit odd to me. New Year’s Eve? Ball drop? Buh…what? It was an excuse to stay up late, partying and making noise, and I never gave it much thought. Years later I learned the ball drop actually has a fascinating precedent, tracing its roots to one of the most pivotal inventions of modern commerce…

The marine chronometer was the first mechanical clock of sufficient precision to determine a ship’s longitude, based on the difference in the displayed time and the observed “local noon” time. It was largely the work of a single person, English carpenter and self-taught clockmaker John Harrison (1693–1776), who persevered in developing and refining his invention despite being largely overlooked by the establishment.

From the 1820s through 1920s, major shipping ports worldwide were home to observatories equipped with time balls, large and sometimes brightly-colored spheres that could be easily seen from ships in the harbor. At a fixed time each day (typically 1pm local time), the time ball was dropped so that all ships could precisely synchronize their clocks.

Prior to the invention of the chronometer, global navigation could be a hit-or-miss, potentially deadly endeavor. Harrison’s clocks in their day were as significant an advancement to maritime safety as the later inventions of radio and GPS, and opened the world to trade and travel.

It all comes back to science. So, this New Year’s Eve, as you watch the ball drop, raise your glass in a toast to Mr. Harrison and his amazing clocks.

Image credits: By Clare Cridland (Macy’s Times Square crystal ball, New York City) [CC-BY-2.0 (www.creativecommons.org/licenses/by/2.0)], via Wikimedia Commons. Chronometer, photograph by Mike Peel (www.mikepeel.net). [CC-BY-SA-2.5 (www.creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons. Greenwich Observatory, by Green Lane (Own work) [GFDL (www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0-2.5-2.0-1.0 (www.creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Yay! RobotGrrl has written up an awesome instructable detailing the process of making your very own RoboBrrd robot! She writes:

RoboBrrd is an robot / animatronic character whose purpose morphs to mirror that of the virtual world. It is designed to be used as a tangible real world interface to virtual world learning applications. As a standalone robot, RoboBrrd is an entertaining platform that can be used to learn about robotics, Arduino, circuits, and programming.

This Instructable will guide you through creating a RoboBrrd- all the way from the circuits to programming to the felt decorations. We will also include reasoning behind our design choices to further enlighten the Instructable.

This is a great robot project for kids and parents to build together — it’s low-cost and doesn’t require any special tools. Having seen it in person, I can also attest to how charming it is.

You can also check out this mini-interview I did with RobotGrrl at the Open Hardware Summit, in which she talks about Learning Pet, a smaller version of RoboBrrd:

Awesome work, RobotGrrl!

Partial parts list:

Standard Servos, Micro Servos, Arduino Uno, Proto Screwshield, Photocells, Hookup Wire

Radioshack is now sponsoring a series of videos about DIY electronics via MAKE. According to some previous announcements there are a few thousands stores that have (or will have) Arduinos on the shelves too.

Mayan Water Sound Fountain…

Here’s an entertaining gadget — a waterfall over a miniature Mayan temple that responds to music. Speakers and lights are built into the Mayan pyramid, and water flows through the center of the gadget for a powerful overall effect. The device includes six main components: a pyramid plexiglass body, a water system, a control unit, speakers, and the output screen with the LEDs.

CONTEST: Make an “Electric Halloween” graphic, each day this month we’re going to feature a cool project from around the web that has electronics AND has something to do with Halloween. We don’t have a graphic for this effort so we’re going to have a contest. Just make a graphic for “Electronic Halloween” and post a link to it in the comments. We’ll pick our favorite one and use it for our posts!

THE PRIZE: $150 in the Adafruit store!

DETAILS: Make the graphic (at the most) 600 x 600, it will be used on each post here for the projects we feature! Make it Creative Commons BY-SA 3.0. Deadline, let’s say October 8th!

Good luck!

A little project I’ve been working on: a variation on the classic Atari Punk Console circuit. I built the original, but then I decided it didn’t make enough noise, so I added some additional hardware to generate a whole lot of that good stuff.

Provided I can get it inside a proper enclosure, I’ll be bringing this to MakerFaire in NYC on Saturday. Be sure to say hello!

Instructables user cubeberg has posted about how he turned a cheap Tron Identity Disc into a prop for his daughter.

In this Instructable, I cover modding the store-bought Deluxe Identity Disc to an upgraded version with 64 leds, controlled by an AVR MCU. The upgraded version is costume-ready and would be an excellent addition to your Tron costume – it’ll also look great on your desk/dresser/etc.

Last night on the show+tell, I talked about the little steam engine I built last fall. It’s a horizontal single-cylinder, 1cc displacement, with a scotch yoke drive mechanism. It’s a combination of manually-machined and CNC-machined parts from aluminum and brass stock. Everything but the mounting bolts, the shaft bearing, and the scotch yoke dowel pin were made by me. It runs at about 3500RPM at 30 psi. Below is a short video I made of it running:

You can also check out this little stop-motion vid I did of the drive mechanism:

Finally, if you want to learn more about how scotch yokes work, and see how they differ from the typical crank arm and connecting rod linkage, you should check out this excellent demo at Wolfram Research, which illustrates the accelleration and velocity curves of each.

Giorgos writes in…

I hacked a normal keylock and added an RC servo to pull the “tongue” of the lock. A PIC16F1937 is used to control the servo. The keypad has a second PIC 16F1937 which acts as a 10-buttons capacitance touch sensor. The controller PIC stays into sleep all the time to save power. In sleep mode, the device draws 16 micro-amperes. When the operator pulls the door gently, a mechanical switch wakes up the controller PIC (with a pulse to RB0/INT port) which in turn provides power to the touchpad.

To open the door, you pull the handle, enter the code, pull the handle again to activate the servo.

To change code, you pull the handle, enter the code, pull the handle again but you keep it pulled for 3 seconds until you hear the distinctive long beep. Then you enter the new code two times for confirmation.

It can hold codes from 1 to 125 digits for those who have good memory. The keypad has a built-in LDR to check ambient light, and if it is below a certain level, it activates the backlit LEDs (4 SMD blue LEDs).

The Microcontroller-Operated, Pneumatically Actuated RLD (Really Loud Doorbell)…

Ed Nauman had a problem. When he worked in his garage machine shop, the noise levels were often so loud he couldn’t hear the doorbell. He resolved the situation by creating a microcontroller-operated, pneumatically actuated doorbell, or a “Really Loud Doorbell.” He calls it RLD for short. He started with a heavy chunk of steel that would resonate as well as withstand the punishment from a pneumatic ram. It’s the beginning of a heavy metal doorbell!

Turn off the Heater behind Me…

Ed Nauman had a bad habit of leaving his workshop at night without turning off the heater. His wife would get up in the morning and find – to her consternation – the workshop was plenty toasty. In the interest of keeping peace in his household, Ed decided to create a gadget that would save the energy spent through forgetfulness. He knew he could buy an off-the-shelf solution, but as he says, “Where’s the fun in that?” Instead, Ed turned to the world of thermostats and microcontrollers.