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.

Up, not North – Portal turret plushie… Jon writes -

When I finally got around to playing Portal, I was a bit surprised at how much the Internet loved the companion cube. Sure, the cube is pretty great, but in my mind it pales in comparison to the turrets, the real scene-stealers of the game. In fact, they inspired a Veruca Salt-esque covetousness in me.

I wanted one.

Badly.

And, of course, it just wouldn’t be the same if it didn’t talk…

With the excitement of Portal 2 coming out, and in collaboration with Leigh Nunan, I finally was able to get my turret. Or, rather, to make it.

Nice tutorial!

We love EMSL so much, it makes us want to drink (more)….

Barbot 2011, the cocktail robotics exhibition, is happening on Friday and Saturday nights this weekend– April 1 and 2 –in San Francisco. If you haven’t been to one of these events (and you happen to like both cocktails and robots), let me tell you: you are missing out.

Last year we built the aptly named Drink Making Unit for the event. The Drink Making Unit used three -ahem- food-safe pumps to craft white russians, and was quite a hit at the show– especially amongst people who recognized the pumps.

This year, we’ve designed a brand new bartending machine, Drink Making Unit 2.0, which we are pleased to unveil today, and unleash upon the world this weekend.

Aside from the once-again-apt-but-not-very-descriptive name, Drink Making Unit 2.0 has very little in common with last year’s machine. The mechanism is all new, and features elements borrowed from sources as diverse as pet stores, chemistry labs, and Japanese gardens. It dispenses any six fluids (up from three), in metered and selectable quantities, and also sports an all-new extra-snazzy control panel.

Woodstove Temp Monitor and Alert…

Paul Westaway wanted to make sure his woodstove didn’t exceed the upper limit of temperature and overheat, thus damaging the stove or causing a fire. He wanted a monitor that could send out an alert if the stove got too hot. He was surprised he couldn’t find a monitor available commercially. So, like any enterprising Gadget Freak, he decided to make one of his own. Using a handful of inexpensive components, Westaway created his own Woodstove Digital Temperature Monitor.

“RGB Lights for Mykle’s Lightbar” – nice work!

NEW PRODUCT – Digital programmable LED belt kit. By popular demand, we now have a project tutorial for how to make your own programmable, ultra-blinky LED belt. Perfect for parties, raves, parades, weddings, funerals, and bar mitzvahs. Wear it with pride, wear it with blinky! Follow our soldering tutorial to build your own heirloom LED belt, and hand it down to your grandkids.

We designed this project to demonstrate how to use the digital LED strip, how to use our Atmega32u4 breakout board with the Arduino IDE and how to make a portable battery powered project that runs off of AAs. This project is not too difficult, and can be finished in a day. Some soldering experience is good since ‘free wire’ soldering is a little more difficult than soldering to a PCB, but even beginners should be able to manage. We don’t include a tutorial on using the Arduino IDE so its good if you’ve played around with the Arduino already.

The pack contains the following:

• Atmega32u4 breakout board (the brains!)
• Digital LED strip – 1 meter
• 6-pin IDC cable
• Inline cable pair (male and female)
• 4xAA battery holder with a switch
• 1N4001 diode
• 3″ of 3/32″ heatshrink
• 2″ of 1″ heatshrink
• Zip/cable tie

You’ll need some very common electronics tools to make this project:

• A soldering iron and solder
• Wire cutters and wire stripper (or a tool that does both)
• Heat source like a heat gun, hairdryer, or lighter
• Any kind of pliers
• A 3rd hand tool or panavise or some other way to keep your work steady
• A basic multimeter can be handy

You’ll also few more things to complete and power the project: a very common mini-B USB cable (for programming the belt) and 4 AA batteries for powering it. You can use alkaline or rechargeables. The belt will last for 6-12 hours depending on what designs you program in – more LEDs will drain the batteries faster.

Be sure to see the full detailed tutorial over at the project page In stock and shipping now!

Electronics for Absolute Beginners (PDF)…

Want to learn something about electronics, but don’t know where to start? Electronics for Absolute Beginners is a one day course that I originally designed for the women’s arts and technology group MzTEK. We had an excellent first run in January 2010 with lots of enthusiasm, and considerable skill from all the participants.

The course introduces the key electronic components and tries to give an intuitive feel for how circuits work. It provides plenty of opportunity to try experiments on the circuits suggested and should give people enough understanding to feel they can build and modify circuits in future.

Each stage of the course introduces new ideas that build and develop throughout the day. There are lots of fun circuits ending up with an electronic organ and a chain-light sequencer.

EMSL writes -

Here’s an neat idea for a jack-o’-lantern: Hide a single white LED just beneath the thin surface of the pumpkin. And program it with the same slow “breathing” effect that indicates sleep on Mac computers. The result? A pumpkin that sleeps like a Mac. It’s actually quite striking, in part because the effect becomes invisible every few seconds. It’s also an easy microcontroller project: our demonstration video and build instructions follow.

• HOW TO – perform bottom vision tests pre-placement
• HOW TO – define leadless parts!
• HOW TO – using closed loop vision

oomlout writes -

We do quite a bit of soldering at .:oomlout:. and as all will know proper air flow when doing so is important. Until now we’ve been taking a hammer to the situation by turning on a large fan. However as the temperature begins to dip that solution is growing more and more unpleasant. To tackle this we bought some 80mm PC fans and cut up a small stand to hold them. Now soldering (and breathing) continues apace, just without the jacket.

LenP17 built a capacitor meter using the new Adafruit Arduino enclosure and LCD. The cap in question is placed in the sweet spot of a 555 circuit, and the resulting frequency is measured, correlated to a particular capacitance, and then displayed by the Arduino.

More info in the forums.

Nice work, Len!

TV-B-Gone hat! We are also really enjoying our pal Sean’s latest projects at MAKE’s new Make: Projects site…

• Hollow-Core Door Table
• Ball-in-Cage Alarm Switch
• Label-etch a Glass Bottle

I’ve divided it into two parts: The first part details how to build a small, inexpensive cyclorama (shooting platform) and the second covers setting up the lights and taking the photos. It assumes you are starting with little more than a camera and a subject to take pictures of. I’ve tried to address a number of questions I’ve received from folks regarding things that are unique to photographing electronics. These include how to photograph lit LEDs and how to make the stamped text on IC packages appear clearly in photos without being washed out.

I’m going to introduce two lighting setups. The first one uses two light sources, and the second one uses one light source and reflectors. The two-light setup is simple, and is good for things like documenting your project as you build it, time-lapse assembly stuff, and general documentation. The one-light setup is more complicated, but also more creative, and is useful for taking final project photos. It also cures baldness, makes you more attractive, and builds self-esteem. Awesome!

I will not be discussing shooting tents in this article. These are already well-documented and ubiquitous all over the web, and in my opinion they don’t teach you a great deal about creative lighting. That isn’t to say they aren’t useful, or produce bad results. They have their place, and for many things they do work amazingly well. That said, the main goal of this article to provide the reader with a basic photo skillset, and I think a shooting tent just hands you the solution instead of teaching you how to solve the problem.

Ok, now that that we’ve gotten the philosophical stuff out of the way, let’s get to work!

What You’ll Need

The cyclorama is a separate project, and has it’s own list of ingredients. However you will need the following items to take pictures regardless of whether you build the cyclorama or not.

Camera — A digital point-and-shoot is fine, as long as you can turn the flash off and it has a macro (close-up) mode. An SLR camera is better, but not necessary. A film camera is fine too, if that’s all you have, though shooting on film may cause some color balance problems if you use incandescent lights. I am using a Canon PowerShot G5. The Canon “G” series provides a great deal of control and older models can be had cheap on eBay. Note: the G7 does not support RAW image capture out of the box, but you can use CHDK to enable this functionality (thanks to Moritz for the tip!)

Lights — You need two, and it’s best if they are identical. You can use work lights from the hardware store if you have to, but I recommended investing in “professional” photo lights from a photo supplier (see list at the end of this document). Often these come up pretty cheap on auction sites or at photo flea markets (~$25, as of mid-2010), and they are a good investment if you plan to use them regularly. If you’re going the work light route you should get the ones marked for 300W lamps. These have a heavy-duty cord and ceramic socket. You should not attempt to use the cheaper low-wattage lamps with a higher rated bulb — even if the cord can handle the current, the plastic base probably won’t be able to handle the heat of the bulbs.

Light Bulbs — In photo and theater-lighting speak these are simply called “lamps”. You should get proper photoflood lamps from a photo supplier, rather than using the 300W lamps from the hardware store. Two common types are ECA (250W) and ECT (500W) — both of these burn at a color temperature of 3200 Kelvin, which is the standard color of photographic tungsten lights. Some people like to use daylight-balanced CFL lamps, but there is a tradeoff. The lights don’t generate as much heat, but their color rendition is poor compared to tungsten lamps. For any of the science-minded who may dispute this, I suggest you look at the spectral output of both: CFLs are a pretty much a picket fence, while incandescents are mostly continuous (though admittedly biased toward IR). The high-powered fusion of the sun puts out a mostly continuous spectrum, overlayed with Fraunhofer spikes, and this is what our eyes (and our camera sensors) are designed for. Gaps in the output spectrum of CFLs cause some colors to be rendered unnaturally, so it’s better to use a continuous-spectrum source.

Tripod — You can work without one if you must, but it is strongly recommended that you use one for critical shots. It helps ensure your photos are consistent and without blur. The heavier the tripod, the better — the greater mass helps dampen vibrations.

Physical Space — You need some space to take your photos, as well as a sturdy table on which to set everything up. You also need room around the table to set up your lights and to move around. The cyclorama shown here has a footprint of about 2×2 feet — keep that in mind if you decide to use it.

Part I – Cyclorama

A cyclorama is a surface that provides you with a uniform background. A cyclorama (also called a cyc, rhymes with “bike”) can vary in size from a tabletop (such as this one) to a warehouse (used for cars and other large objects). It’s really nothing more than a concave surface of uniform texture — it’s horizontally flat in the front and curves up to vertical in the background. The one we’re going to build here uses a lightweight frame of PVC pipe and a sheet of poster board, along with a few thin panels of MDF for extra rigidity. It costs about $20 in parts. If you are using a table that sits up against a wall, you can skip the PVC frame and simply tape the poster board to the wall and table in the appropriate shape. However, you may find the PVC frame gives you more flexibility because you can move around it. The added bonus is that it’s a good excuse to use power tools.

Parts List:

1. 12ft of 3/4” Schedule 40 PCV pipe
2. 6 90° elbows (3/4” sch. 40)
3. 2 tee joints (3/4” sch. 40)
4. 2’x4’ panel of 1/4” MDF (or 3/16” hardboard)
5. 1 sheet of white posterboard (22”x28”) — get a few extra if you can.
6. 2 small binder clips

Cut the PVC into seven segments of 18” in length. Cut the remaining pipe into two pieces of 3” each. Follow the photo for assembly instructions. It really doesn’t matter in what order you put the pieces together as long as you square it up when you’re done. You can use pipe cement too if you want, but there’s really no need. If you leave the pieces loose, then you can take it apart later for storage.

Now it’s time to cut the MDF panel. You’re going to cut two pieces, one 16”x24” and the other 20”x24”. Lay the 16” piece across the bottom and lay the 20” piece up against the back as shown.

If you want to, you can secure the back piece to the frame, though you can just lean it against the back. Take the posterboard and install it as shown, shiny side up.

Clip it to the front edge of the MDF with binder clips and form the curve (an arc of about 3” radius). Once you have the curve the way you like it, tape it to the back board with masking tape.

If all went well, your cyclorama should look like the one in the photo. Congratulations!

Part II – Taking Photos

Ok, so you’ve got your cyc all set up (or not) and you’re ready to take some pictures. There’s no trick to it, it’s just a simple trick. In short, it really doesn’t matter what camera you have, because it’s all about lighting. Your control of the light has the biggest impact on the final product. Composition is important too, but if you have good lighting, the right composition tends to become self-evident. Further, good lighting allows you to show all the details in your work with equal clarity.

The most important thing to remember with lighting is control. You need all the control you can get. This first translates, in this case, to working in a darkened room, preferably at night. The only lights you want falling on the subject are the lights you can control. Light coming in through a window can be very beautiful, but you don’t have a whole lot of control over it, so draw the curtains.

Before you set up the lights, you should place your subject in the middle of the scene. If you’re using the cyc, you want to place it about 4-6” back from the front edge, and centered left to right. It helps if your project can stand on its own. If it doesn’t, you can use adhesive puddy (Fun Tak), to help prop it up to the angle you like. Please note that from this point on, I will be referring to the placement of lights and reflectors as being in position around a clock, with the subject at the center.

Two-light Setup

In this first configuration we’re going to use two lights. There’s not much to talk about here — this is a very basic, functional setup that works well with documentation photos — that is, pictures you take of your project as you’re working on it. It doesn’t work so well for shooting “finished” projects, because it produces some confusing shadow patterns that can be distracting. However, for shooting while you work, it’s the best compromise between quality and expediency.

You should have two matching lights, with bulbs of equal output. Some folks like to put diffusion material over the lights. You can do this if you like, as it does soften the shadows a bit. If you do this, remember that the diffuser absorbs some light, so your exposures will be longer. Also, be mindful of the heat produced by the lamps — you don’t want the material to melt. Try to use heat-resistant diffusion gels, such as those sold by Rosco.
For your start position, set both lights at the same height, about 3 feet above the table surface, and pointed at the subject.

Imagine a line connecting the center of the light bulb to the subject, and another line parallel to the front edge of the table that runs through the subject. These two lines should intersect at an angle of about 45 degrees. This is a good starting point, because it eliminates shadows as much as possible. You will still see some shadows, of course, but we’ll take care of those in editing later. Looking at things from overhead, the lights should be at about 4 and 8.

The camera is at 6 o’clock. The distance from the camera to the subject varies depending on what you’re taking pictures of, but 18 inches away is a good starting point. Bear in mind that it is not necessary to fill the frame with the subject, as you can crop it later. In fact, it’s not advisable to be right on top of the subject with your camera, as it makes it more difficult for you to work (directly under the lights), and it can cause focusing problems. Plus, by moving further away you increase your depth of field, helping everything to be in focus.

If you have your lights set up properly, you should be ready to take some photos. The next section provides some details and hints about using the camera.

About the Camera

Before we continue, I’d like to mention some things about the camera. These are given generally, and you may need to consult the camera manual to learn how to make these changes on your particular camera:

1. Use a tripod.
2. Flash: Turn it off because you won’t need it. It’s usually controlled by a button with a lightning bolt on it. The screen will display a “no” symbol (as in “no smoking”) with a lightning bolt inside it.
3. ISO: Set your camera’s ISO (film speed) to the lowest possible setting. This is usually 50, 100, or 200. Avoid using the AUTO setting. Different cameras have different ways of doing this, refer to “ISO” in the manual.
4. Aperture-priority mode: Put the camera in Aperture-priority mode. For SLRs and advanced point-and-shoots, this is usually accomplished by turning a dial on the top or back of the camera, and is denoted by an “A” or “Av”. For starters, set your aperture to 4.5. Once you get a feeling for how changing the aperture affects the picture, you can change it to suit your tastes. The aperture affects what is called “depth-of-field”, which is the area from nearest to farthest that is in focus. For most picture taking with point-and-shoots, this isn’t much of a concern. However, when you are shooting close-up you need give it some thought. The higher it is (the greater the depth of field) the more of the image will be in focus. For things that are very close up (less than 12 inches), you should set it to maximum. If you still can’t get everything into focus, try moving the camera back a bit and then cropping later in an editing program.
5. Image quality: Set your camera to the largest image size available, and with the lowest compression setting (i.e. the largest file size) — this is usually called “fine” or “superfine”. If your camera supports RAW output, you can use that. RAW images store the full output of the camera sensor and are more suited to later editing. For the purposes of this tutorial, I’m going to be working with JPGs from the camera. There are plenty of resources available regarding RAW image workflow if you are interested in that.
6. White balance: Set it to incandescent (aka “tungsten”). This is usually indicated by a little light bulb icon. This sets the color balance of the camera to a color temperature of 3200K, which is the color temp of the light’s we’ll be using. I won’t go in to what color temperature is or how it’s calculated, because it’s a bit involved. Suffice it to say it’s based on one of those ideal theoretical constructs physicists are so fond of.
7. Focusing mode: For most stuff you can use the camera’s autofocus mode. Manually focusing a point-and-shoot is often more trouble than it is worth. It’s quite easy to do on an SLR, but most modern AF systems work so well that it’s doubtful you’ll be able to improve upon things. That said, there are some things to keep in mind when using Autofocus. AF systems require contrast to focus properly, so pointing the focusing window at a broad expanse of solid color will cause problems. Try moving the object or camera a little to give the camera something “busy” to look at. Flashing LEDs can also seriously throw off an autofocus system. If you see the camera oscillating in and out of focus, and you have flashing LEDs, try moving things around as above, or change the LEDs to a steady pattern. If that doesn’t work, you may have to manually focus the camera.
8. Macro mode: Many cameras have a “macro” mode, which is engaged by a little button with a flower icon. Macro mode allows the camera to focus on subjects very close up. This mode usually works best when the lens is zoomed all the way out (wide angle), and zooming in past a certain point may actually turn the mode off. If you find that macro mode keeps turning off, this is probably why. However, you might find you prefer moving the camera back and zooming in as opposed to getting in real close. This tends to “flatten” the field of view a bit, whereas getting up close with a wide angle can result in an exaggerated perspective. The other nice thing about zooming in from further back is that you constrain the field of view to an area where you have full control of the light, resulting in a more even lighting in the photo.
9. Self-timer or Remote: Most cameras have an adjustable self-timer, and some have remote trigger as well. These are both very handy features to have, and you should use them if you have them. The reason is because when you are holding the camera and pressing the button, you introduce some vibration through your arm which can cause the photos to be blurry. By either delaying the shutter until your hand is away, or firing the camera remotely, you can eliminate this problem. On a related note, be sure that the floor isn’t vibrating when you take the picture (i.e. don’t walk around near the tripod), as this can also cause blurry photos.
10. Use a tripod. This tip is similar to tip #1, except I really mean it this time.

Tips for Taking Pictures

Ok, so now it’s time to take the photos. Assuming you’ve followed the tips above, you should be able to take a picture of your subject. The only thing remaining is to check the exposure. For feedback on this, we need to look at the histogram. The histogram looks sort of like a spectral graph (like in a spectrum analyzer for your stereo), and it shows you how much of each tonal value is in the photo. Most of the time, it resembles a sort of mountain range. The position of the histogram is related to the brightness of the image. If it’s shifted to the left, that means most of the values in the image are dark, and if it’s shifted to the right, it means most of them are lighter. The best place for the histogram to be, in most cases, is in the middle. This means we have an average tonal distribution with some highlights and shadows. See the photos for examples.

If your histogram is shifted far over the right or left, you need to adjust the exposure. Assuming you are in aperture-priority mode, you want to look for the exposure adjustment controls. This is usually indicated by a “+/-” symbol. When you press this button (sometimes you have to hold it down while you make adjustments), you’ll see a scale going from plus to minus in indexed increments. Often, exposures are thrown off by the background. If you’re using the cyclorama, you’re shooting on solid white and so the camera thinks it’s brighter than it really is. To remedy this, you need to set it to more exposure.

You do this by moving the pointer over towards the “+” symbol, usually by about 2 or 3 index points. If you’re shooting on a black (or dark) background, you need to do the opposite.

The histogram is the best indicator of good exposure — don’t go by what the picture looks like on the LCD, because it’s always wrong. ALWAYS. It’s only there to give you a general idea of the composition and focus. Don’t bother using it for anything else.

One-light Setup

No reflectors

The next configuration we’re going to use requires one light and a few reflectors. While this sounds limiting, it’s actually got a lot of flexibility. The natural world is, after all, basically one light (the sun) and a reflector (the sky). The reflectors are the key. Much of the light radiated by a light source is wasted, traveling in directions that contribute nothing to the photo. Reflectors help bounce (and sometimes diffuse) that light back onto the subject, filling in shadows and highlighting critical areas.

There are two reflector types we’ll be using, and they each do different things.

White panel reflector (off to right)

The first is a diffused panel, which is basically a piece of white cardboard or foamcore.

The second is a mirror. We use each of these reflectors for a different purpose, but rather than detail each purpose now, I’ll explain them individually as we introduce them to the set up.

First, the light. Place the light at about 3 feet above the surface of the table. Set it 4 feet away and at the 9 o’clock position (off to your left), and pointed at the subject. Leave enough room to move it ±1ft towards or away from you later.

There’s always the temptation to put the light as close as possible to the table. While this does increase the amount of light, it is very uneven illumination — the gradation from light to dark across the background (and even the subject) can be very noticeable. This is due to the nature of light as electromagnetic radiation, which means it is governed by the inverse square law. I won’t go in to calculations here, but it’s best to remember that the closer the light is to the subject, the higher the contrast between light and shadowed areas. When you move the light away a bit, things tend to “even out” a lot more — it also makes it easier to work because you don’t have a hot, high-wattage incandescent light right in your face.

If you look at the overhead photos, you’ll see where each reflector is placed for this particular setup. Naturally, every subject will require a different placement of the mirrors, and some may not require you to use all three. There’s a lot of trial and error here. Set up your subject in the “pose” you like, light it, and then add and move the reflectors around until you get what you like.

White panel reflector

With the light in position, we’re going to introduce the reflectors. The first reflector is a diffusion panel (sometimes called a white card). 1/4” white foamcore works great for this best because it’s lightweight and rigid, but you can use any sort of white panel. You’re going to prop it up on the right side of the subject, about 12” away. If you’re using the cyc, you can just lean it against the side as in the photo. Watch the shadows cast by the subject darken and lighten as you remove and replace it in position. Our goal with the reflectors is to lower the contrast ratio, which is the proportion of the lightest part of the scene to the darkest part. Digital cameras have problems resolving higher contrast scenes, and so we need to bring the contrast down to a level where it can record everything. If you move the reflector away from the subject, the contrast increases, while moving it closer causes it to decrease.

White panel + 1 mirror

White panel + 2 mirrors

White panel + 3 mirrors

Next we’ll introduce the mirrors. I have three mirrors, one big one (5”) and two small ones (3”). These are the kind you can get at a discount store — make-up mirrors with a collapsible handle that allows you to stand them up on a table. They usually have mirrors on both sides — one is flat and the other is concave. The small ones cost about $3. Buy them in black if you can.

Where the mirrors go in your setup depends on the subject. You want to look for spots on the subject that look particularly dark, and use the mirrors to fill them in. Start with the largest mirror. Think of this as starting with a broad brush and working your way down to a fine tip for the details.

Looking at the photo with just the white panel, we see that the lower-right side of the subject is still much too dark. We need a significant amount of fill here, so we use the large 5” mirror to bounce some light back onto our subject. (photo & overhead #3).

Now we’ve lightened up the lower right a bit, but the area around the chip is still too dark, so we add another reflector off to the left of the camera to throw some light in that area. Note that this mirror is set at a rather shallow angle, in order to catch the light from the source and reflect it to where we need it. (photo & overhead #4)

I shot this on my workbench with one light off to the left, and two reflectors (mirrors) filling some of the shadows.

Finally, we still need some light to the right of the microcontroller, around LED7. So we put the last small mirror to the left of the big one and lighten this area up a bit (photo & overhead #5). Then we take the photo, and we’re done!

See the whole thing in action:

Just one note: like anything worthwhile, it takes a while to get good at doing this. You need to practice and change things up now and then in order to learn what looks good and what doesn’t. And you don’t have to stick to the cyclorama as a background either — you can use any tabletop/background, provided you have the room to move the lights and reflectors around. Take a look at the last photo in this section. I did that one on my workbench with one light and two reflectors. I actually like it more than most cyc shots, because it has context. So don’t be afraid to play around and find what you like.

Tips for LEDs

One thing you’ll notice in the pictures above is that the LEDs are rather well balanced with the rest of the picture. One of the advantages of using the lighting method presented here is that there is plenty of illumination available to light up the rest of the PCB and components, allowing  them to “match” the brightness of the lit LEDs. There’s an added advantage in the above example because the LEDs on the Game of Life board are diffused, which cuts down on their output a bit. That said, every LED is different — some are diffused, some are clear, and they have different levels of output. If you’re trying to shoot a project and the LEDs are just too bright, there’s a few things you can try:

1. Try using brighter bulbs in your light sources. If you’re using 250W bulbs, for example, try switching to 500W.
2. Move the lights a little bit closer to increase the brightness of the scene. This will have an affect on the shadows and contrast too, though, so don’t be too extreme in your adjustments.
3. Add another light. It might surprise you to learn that two lights is brighter than one light!
4. Reprogram the circuit to put out a lower LED level. This only works if you have PWM control over the LEDs, but it works quite well.

.

EMSL writes –

Recently we put together this interactive Game of Life display as an educational adjunct for a new exhibit by the San Jose Museum of Art on the works of Leo Villareal. Leo primarily works with light sculptures, and we’re very excited to see (and participate in) the exhibit, which opens this Friday.

A reflow toaster/plate controller… tune in live as we build this project

Code entry to your garage using a doorbell and an attiny13 via HaD. Mike writes -

I wanted to use an ATtiny13 microcontroller because I had ordered a half dozen a few years ago and still had most of them sitting around. This meant I would need to fit the code into less than 1024 bytes of programming space. I downloaded Alan’s code thinking it might be in C but it turned out to be BASIC so I decided to write my own from the ground up. I did start with my favorite Danni Debounce code (written by Peter Dannegger) to handle the button presses and coded a prototype using an ATmega168. Here’s how it works…

We are putting more of our projects on github for eazy forkin’ – here are two we just tossed up there, enjoy!

http://github.com/adafruit/Conways-Game-of-Life
http://github.com/adafruit/Ice-Tube-Clock

Amazing Daft Punk helmet! (Flickr set)…

Its been a long road. Seventeen months, countless hours, multiple dead ends, hundreds of lessons learned, and one helmet made. In the past two installments I’ve discussed sculpting, resin casting, chroming and vacuum forming. This is where the magic happens though… Illumination.

Nice work!

Did you know you could be a rocket scientist in just one day? Well, a hobby rocket scientist anyways! The field of hobby rocketry is huge, ranging from $5 mini starters to multi-thousand dollar custom made giants that can fly thousands and thousands of feet. Today we’ll show you enough to get you up in the air and crashing in no time!

More:

Sylvia’s Super-Awesome Maker Show – Maker Faire edition!

Sylvia’s Super-Awesome Maker Show: Episode 01, Drawdio – outstanding!

Super Awesome Sylvia builds the Drawdio by Jay Silver from the kit by Adafruit! This doesn’t include a complete tutorial on bulding the kit, as Ladyada has done such a good tutorial [here]…

This is very very nice….

Dear Ladyada (Limor), Thank you soooo much for signing my autograph book. I know you were busy and had lots of things to do, but you still gave me some time! Thank you!! You are so amazing for all the cool electronic and crafty stuff you work on. It’s hard to find other girls who like electronics and robots and stuff anywhere, but your stuff helps me and dad says you’re a great role model. We bought your motor shield and the wave shield for our little robot. I helped solder both of them and maybe soon we’ll have our little bot rolling and talking!

“Play with my Giant Joystick” – The Pacinator. Jeri writes -

I show how I made a working giant joystick from home improvement materials that looks similar to the one in Joysticks the Movie.

How to Roll Your Own iPhone Data Recording Cable @ Backyard Brains via via.

Many users, while enjoying the SpikerBox demo’s we have done, have also expressed excited curiosity that the iPhone can be used as a portable data recorder / oscilloscope. To truly take advantage of your iPhone though, you want your signal to go directly to the line input. Though you can buy one of these cables, in the open-source spirit of Backyard Brains, here is the schematic to build your own. You need: one 4.7 kOhm resistor, one 10 uF capacitor, one 3.5 mm audio three conductor cable you cut in half, and one 3.5 mm audio four conductor cable you cut in half. Bring out your soldering iron, your wire-stripper, and your favorite beverage!

Of course, its only AC coupled, probably +-2V max and 20KHz but still handy for audio techs!

The IEEE Student Chapter at Seattle University created this terrific 5×5 Game of Life display to hang on the wall. aerohoff writes:

Fall 2009, as a senior at Seattle University, I was disapointed with the lack of soldering in my electrical engineering courses. As the co-chair of the IEEE student chapter, I organized a soldering workshop where each student got to solder together one Game of Life board. We connected all the boards together on a display board that will hopefully get put up on a wall somewhere. We got 25 of them together and into a 5×5 grid. The paper on the right explains the rules of Conway’s Game of Life and explains how the board came to be.

Beautiful work!

Fab radio… Final Project – David A. Mellis – MAS.863: How to Make (Almost) Anything…

This radio, created in collaboration with Dana Gordon, is an experiment in the fabrication of consumer electronic products. The frame is made of press-fit, laser-cut plywood and covered with thin front and back face-plates. Any found material can be used for the fabric, which covers the top of the radio and the speaker. Here, we’ve used a souvenir from a trip to India. The electronics, including knobs and power jack, are mounted on a single circuit board at the base of the radio. The whole product is designed to be easily and quickly assembled from fabricated components.

There are numerous examples of individuals producing circuit boards or electronic kits in quantities of hundreds or thousands, but few target a general audience. By carefully designing the appearance and construction of the radio’s case as well as its electronics, we have arrived at a consumer product that can be manufactured in similar quantities. With access to a laser cutter, an individual could manufacture and sell this radio on a scale sufficient to provide significant income. We hope that this example will help inspire the creation of fabrication-based, consumer electronics small businesses.

via Jalopnik:

This is Blackbird, it’s a wind-powered car designed by an aerodynamicist to end a longstanding internet debate, namely, ‘Can you go downwind faster than the wind?‘ Using high-tech designs and precise instrumentation, Blackbird proves you can.

Directly Downwind Faster Than The Wind (DDWFTTW) is a favorite topic of debate across the nerdverse for the combination non-existent answer and apparently conflicting nature of the question. “Wind only goes X-speed, how can you go faster? If you go faster don’t you violate the law of conservation of energy?” That’s usually the way the discussion goes.

+5 BA points!

edit: link to the website. (thanks, David!)

Discovering a Soft Spot for Circuitry – Robot Machines as Companions…

Nothing Eileen Oldaker tried could calm her mother when she called from the nursing home, disoriented and distressed in what was likely the early stages of dementia. So Ms. Oldaker hung up, dialed the nurses’ station and begged them to get Paro. Styled after a baby seal, a robot that blinks and coos when petted is often therapeutic for patients with dementia.

John writes -

Well today’s the day! On the eve of Canada day I have made a giant step towards a good version of the plasma speaker! After letting the magic smoke out of countless ICs and Diodes I have finally put together a working model of the plasma speaker.

Nice how-to on making your own gears from Dustyn Roberts, she writes -

Gears are easy to understand, make, and use, if you know the vocabulary and can space the gears at the correct distance apart. One nice thing about gears is that if you know any two things about them – let’s say outer diameter and number of teeth — you can use some simple equations to find everything else you need to know, including the correct center distance between them.

Build a Sunburn Alarm via HaD.

Ever get a sunburn?  Prefer to avoid them in the future?  Mr. Burns combines information about your skin type and any sunscreen you’re wearing with a realtime UV light measurement to let you know before the burn sets it! 

I had great fun working on a cool Multimeter Clock project which got picked up by Design News for their Gadget Freak series. I thought it would be cool to have a clock that looks like an old Simpson 260 multimeter. The clock consists of three multimeters, the first meter displays hours, the second displays minutes and the last displays seconds. A 16F628A PIC microcontroller keeps track of time and outputs a calculated current to each meter to display the current time.

When you think – “DIY electronics”, one of the first images that likely comes to mind is a bunch of parts and wire soldered to a standard piece of perforated circuit board – and that makes sense. Perfboard is super-versatile – essentially it’s just a grid of potential solder-point connections. You can trim it down to just the size you need – or leave extra space for future enhancements … or revisions, if need be.