[miceuz] has a friend that works as a theatre technician, and in the course of his job he often needs to jigger with various stage components while shows are in progress. As you can imagine, the lighting situation is far from ideal, so he asked [miceuz] to build him an adjustable lighting solution for his tool box.

The circuit itself is relatively straightforward, using an ATMega88 to provide the PWM required for dimming and color control. Input is taken from three different sources, a rotary encoder for color selection, a pot for brightness control, and a button to turn the light strip on and off.

[miceuz] says that while project came together pretty easily, it still presented some issues along the way which provide some useful design reminders for beginners (and some veterans) alike.

First and foremost: debounce, debounce, debounce. [miceuz] forgot this mantra and made a mad dash to add capacitors to his design after etching the PCB to ensure that his inputs were not bouncing all over the place. He also noted that one should always be sure to read the ADCL before the ADCH register when decoding ADC data. His final observation is that using thick traces is the best policy whenever possible – he ran into a lot of issues with traces detaching during assembly, which he had to rework with wire and solder.

In the end, his friend was happy with the result, and [miceuz] is a better hacker for having worked through his issues. What sorts of important/useful lessons have you learned through the course of your projects? Be sure to share them with us in the comments.

The folks at The Quad Cities Collaboration and Hackerspace (QC Co-Lab) were trying to find something to build for their first big project, and had to look no further than the wall for inspiration. The north end of their facility is home to a huge 15×17 glass block wall that happens to face a well-traveled roadway.

They decided that turning the wall into a huge LED display would be a great way to attract attention from passers-by, so they picked up some GE Color Effects lights and got down to business. Once they found out that the technical college next door was putting on an open house, the race was on to get the light display assembled as quickly as possible to maximize their exposure.

The team mounted the 255 LEDs in vacuum-formed reflective cones, which were attached to wooden frames before being installed behind the glass wall. An Arduino drives the entire display at a smooth 30 frames per second, a task they say tests the very limits of the board’s capabilities.

They finished the job in time for the open house, and as you can see in the video below, the display looks great.

Nice job QC-Co-Lab!

[Dino] wanted to make this New Year’s celebration a bit more interesting, but he can’t make it to New York for the ball drop. Instead, he decided to make his own mini display in his workshop. Obviously he’s working with a slightly smaller budget than the folks at Times Square, but we think his display is pretty neat. If anything, [Dino] can at least guarantee that his New Year’s is 100% Seacrest-free.

The ball drop is made up of five ping pong balls, each backlit by a 10mm LED. The LEDs and ping pong balls were mounted on the electron gun from a broken oscilloscope, giving it a cool look. The balls are lit one at a time by an Arduino, which illuminates each one for 15 seconds while the final minute of 2011 is counted down. Once midnight hits, a flashing “2012” sign illuminates while Auld Lang Syne plays from a tiny speaker.

The musical part of this build is something that [Dino] spent a lot of time on. He thoroughly explains how he translated the song from sheet music into its digital form, a process that would be helpful for beginners to watch.

Continue reading to see how the display was built, and if you’re just antsy to see the ball drop in action, a short demo can be found at 12:13.

[Axel] wanted to participate in the CheerLights project this holiday season, but not one to always follow the rules he decided to make his display a bit different than most others out there. While the lights at his house are synchronized with the CheerLights project, he programmed his Cheeriobot with a little added personality.

Normally, Cheeriobot is happy to follow the rest of the world, changing its colors whenever the Twitter feed dictates. If things are a bit slow however, Cheeriobot gets impatient and will send a tweet to @CheerLights on its own to ensure that it doesn’t display a single color for too long.

[Axel] also created a mode that turns Cheeriobot into a bit of a contrarian. The display’s “Rebel Mode” causes it to change colors when someone tweets, but it selects a random color instead of following the rest of the pack.

It’s definitely an interesting twist on the CheerLights project, and we really like the fact that it keeps things moving if the stream of tweets ever slows down.

[Dave Vandenbout] says that his sister has gotten big on Christmas traditions, and decided that the whole family should start making ornaments for the tree each year. Not one to let a chance to tinker with electronics pass him by, [Dave] started brainstorming the perfect electronic ornament for their tree.

He settled on the Christmas tree design you see above, which will eventually hold 15 RGB LEDs. On the back of the board, he is planning on mounting a PIC 18F27J53 microcontroller, which will take care of the LED display along with his other more mischievous components.

You see, undeterred by his sister’s holiday spirit, [Dave] wants to arm the ornament with a foul mouth, and have it attempt to shake other ornaments off the tree. To do this, he’s installing a vibrating motor on the back of the PCB, along with a speaker and MicroSD card to provide the ornament’s sound bites.

To be honest, we think his idea is pretty entertaining, we can only imagine the look grandma will give when the cute, light up Christmas tree ornament blurts out, “Eat me Santa!”

We just hope he sends some video our way once he wraps up the project.

[Steven] had one of those musical gift cards laying around, and thought he might as well reuse the piezo speaker inside it. Without a particular project in mind, he soldered an LED to the piezo and tapped on it, which caused the LED to illuminate as expected. He started to wonder what quantity of force would be required to light the LED, and if it could be done by a raindrop.

He first tested his theory in the shower, and as you can see in the video below it actually worked, though the light was dim and sporadic as you might imagine. He eventually discovered that for optimal lighting, the piezo worked best when struck by single droplets falling with pauses in between, from a minimum height of 4 feet. To achieve a water flow within those specifications, he built a rain funnel so that he can control the droplet frequency and intensity.

It seems to work pretty well from what we can see. Off the top of our heads we can’t seem to come up with any practical applications of the water powered LED, but it is an interesting set of experiments nonetheless.

Have an idea to use this setup that we totally missed? Let us know in the comments!

[Thanks, Rob]

[Udo] figured out how to turn a bunch of LEDs into a very low resolution camera.

The build is based around [Udo]‘s Blinkenlight shield he’s been developing over the past year. The camera operates under the idea that there’s really not much difference between a LED and a photodiode; LEDs can do light emission and detection. In actuality, the LED ‘camera’ isn’t all that different from a linear CCD array, the type of image sensor in flatbed scanners.

After connecting his Blinkenlight shield to his Arduino and computer, [Udo] wrote a sketch that would capture 17 values from his LED camera. These values are shot over the serial connection where high levels of light show up as smaller numbers and low light levels are understood as larger numbers.

[Udo] has been doing a lot of other cool stuff with his Blinkenlight shield, like a persistence of vision experiment and pretending to be [Michael Knight]. Check out the video after the break for a demo of [Udo]‘s linear LED camera.

Our own [Mike Szczys] recently sat down and put together a great tutorial on building a Larson Scanner. The ubiquitous circuit is usually one of the first few projects on a budding hackers list of things to build, since they are just so darn fun.

Simple versions of the scanner sweep back and forth lighting the LEDs without any sort of transition between them. The configuration most familiar to us all as featured in Knight Rider and Battlestar Galactica are a bit more complex, and have a fading trail of light that follows behind the leading edge of the sweep. [Mike] notes that this fading is traditionally accomplished through the use of capacitors, which cause the light to gradually fade as the animation sweeps across the LED array. He decided to take a different route with his circuit, relying on PWM control of the LEDs instead.

Mike put together a simple circuit using an ATmega168, a handful of resistors, and of course, an array of LEDs. Utilizing interrupts and PWM, he was able to accurately recreate the iconic light sweep without the use of any capacitors. One big benefit to his design aside from the lower component count is the fact that he can easily adjust the speed of the sweep as well as the fading properties with a few small code tweaks.

Be sure to check out his blog at some point, where he shares his code, some circuit diagrams, and plenty more details on how his scanner was built. In the meantime, take a look at the video below to see the result of [Mike’s] work.

[Nathan], a member of the DangerousPrototypes forums, was looking for a project he could use to enter the 7400 logic competition they are holding. His kids had a small ride on police car, but the light bar on top contained no lights, and the car made no sounds when his children were in pursuit of baddies around the house. [Nathan] had all the inspiration he needed, and took to his workshop in order to fix this glaring oversight by the toys’ creators.

He designed a circuit based loosely around a Cylon-style light that he saw a while back at the Evil Mad Scientist Labs, which employed an oscillator and a 4107 decade counter to control the lights. His design uses a 74HC04 hex inverter as the oscillator, while the decade counter is used to modulate the siren’s frequency and control the rotating LED beacons.

The final result is great if you ask us. An “unnamed adult female” in the house was not nearly as impressed by the additions based upon how much time [Nathan] spent on the project, but his children were absolutely thrilled.

Continue reading to see a quick video of the revamped police car in action.

[Emily Daniels] recently snagged a free iPad in the Instructables “Play with your food challenge” with an interesting way to work with LEDs. Growing up, most kids attempted to make, or at least have seen rock candy be produced. [Emily] thought it would be interesting to mix LEDs with the stuff to see what she could come up with, and her candied LEDs are the result.

The process is pretty straightforward, and involves mixing up a batch of supersaturated sugar syrup in which LEDs are suspended. The LEDs act as a nucleation point for the crystal formation, growing a nice solid coating of sugar after a couple weeks’ time. After some cleaning up, the LEDs can be connected to a coin cell battery or similar, as you would normally do. The sugar acts as a diffusing medium for the LEDs, giving them a nice soft beam pattern.

Obviously you likely wouldn’t want to use these for any long-term electronics project, but it’s a fun activity for the kids, and it could be a good way to incorporate electronics into baked goods.

Even though Tetris came to the US 25 long years ago, it never fails to entertain. Whatever it is that gives the game such lasting power is a mystery to us, but we’re always interested in seeing fresh takes on the classic game.

MIT students [Leah Alpert] and [Russell Cohen] tweaked Tetris a bit to get players off the couch and literally thinking on their feet. The game boards were constructed using RGB LEDs installed in laser-cut acrylic tubes, arranged in a pair of large 6 foot tall floor standing matrices.

Game play progresses as you would expect, with two players battling head to head to achieve the high score, while simultaneously sabotaging their opponent. Instead of controllers however, each player stands on a Dance Dance Revolution mat, manipulating their game pieces with their feet.

While the DDR pads aren’t exactly a Kinect controller, we have no doubt that playing Tetris this way is incredibly fun – we would certainly install a pair of these boards in our game room without a second thought.

Thanks to everyone who sent this in!

[Jaroslav] was racing slot cars with his son not too long ago, but like many of us discovered in our youth, driving cars around a small oval track can get dull after awhile. Rather than buy more track sections, he decided to fiddle with their cars a bit to make racing them a little more exciting.

After removing the top of his slot car, [Jaroslav] found that it cruised around corners with ease, giving him a distinct advantage over his son. He did the same with his son’s car to level the playing field, then he decided to add a few extra LEDs to make driving around the small track more lively.

Now, this obviously isn’t the most advanced of modifications, but it is a great example of extending the useful life of a toy by using cheap, easy to access components. We think that it would be reasonable to add even more features to the cars/track such as speed-dependent lighting or lap counters without changing the car dynamics all that much.

Any thoughts or suggestions to help [Jaroslav] soup up his kid’s race track even more? Share them with us in the comments.

[Justin] always wanted a GeoChron clock, but since they run in the range of several thousand dollars apiece, he was pretty certain he would never have the chance to own one. Undaunted, he figured out a way to build a small version of the clock for himself, and he wrote in to share how it was done.

He first purchased a Wise Clock 3 from FlorinC, but he definitely wasn’t going to use the clock as it was originally intended. Rather than display the time in numbers, he pulled the Wise Clock apart and sandwiched a vellum printout of a world map in between the front face plates. A tweaked firmware image allows him to simulate day and night using the Wise Clock’s LED array. He also programmed the clock to take into account seasonal light patterns, as you can see in the video embedded below.

We think this is a great idea, and though we would probably use plain white LEDs if we built one, the RGB LEDs in the Wise Clock certainly provide a neat effect.

Instructable user [cubeberg’s] daughter saw Tron:Legacy earlier this year and decided right then and there that she wanted to dress up as Quorra for Halloween. Being the awesome dad he is, he decided to make her costume himself, and hit the stores in search of an Identity Disc to complete the look.

The toy was pretty underwhelming, and lacked the lighting that a proper Tron prop should have. He figured he had the skills to make it a bit better, so he gathered some tools, a bunch of LEDs, and set off for his workshop. He gutted the disc, cutting out any extraneous bits of plastic he could find. He wired up 64 LEDs between the disc’s inner and outer ring, which he controls using an ATmega 328 paired with a Max7221 display driver.

He doesn’t show any pictures of what the toy looked like beforehand, but the final product looks great. We bet that his daughter is pretty pumped for Halloween to roll around – we know we would be.

Continue reading to see a quick video demo of his souped up Identity Disc in action.

Like many of us, [Bertho] has had plenty if interaction with “Executive” types who seem to make decisions randomly, and most certainly not based upon any sort of reason. As he was picking through parts bins at his local hackerspace, he thought it would be fun to build an “Executive Decision Maker”. The device he had in mind would answer questions at the push of a button, with the kind of randomness that could only be carefully honed through years of barking orders from a corner office.

Constructed from third-rate LEDs and old CMOS chips that were lying around, the operation of the device is quite simple. Much like a Magic 8 Ball, a question is posed, and as [Bertho] states, “The Executive Decision maker automatically tunes into the aether and the subconscious of the user” pressing the “Decide” button. The device then makes a judgement, relaying its answer to the user via an LED display.

We definitely got a good laugh out of this one, so be sure to check out the video after the break to see the Executive Decision Maker in action.