The Megascroller, For Video Games In The Round

megascroller

The folks at NYC Resistor have a thing for circular displays, it seems. Their earlier Hexascroller was a ceiling mounted display with six 30×7 displays – good enough to display the time and a few textual message in six directions. The Octoscroller bumped up the display capability with eight 16×32 RGB LED panels. Now the Megascroller, a 32-sided 512×64 display is hanging in the hackerspace, complete with 360° Mario and Pong.

The Megascroller is one of [Trammell Hudson]’s projects, constructed out of sixty-four 32×16 RGB LED matrices. That’s an impressive amount of controllable LEDs, that required a lot of processing power: namely, the BeagleBone-powered LEDscape board used in their earlier Octoscroller

As far as applications go, they naturally have Pong, but a more interesting application is the side-scrolling Mario that requires you to move around the display as you play. You can check out a video of that below.

If you’d like to see the Megascroller in person, as well as a whole bunch of other crazy blinking interactive projects, NYC Resistor is holding a an interactive show this weekend, beer provided.

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Koch Lamp is 3D Printed with a Twist

Koch Lamp

[repkid] didn’t set out to build a lamp, but that’s what he ended up with, and what a lamp he built. If the above-pictured shapes look familiar, it’s because you can’t visit Thingiverse without tripping over one of several designs, all based on a fractal better known as the Koch snowflake. Typically, however, these models are intended as vases, but [repkid] saw an opportunity to bring a couple of them together as a housing for his lighting fixture.

Tinkering with an old IKEA dioder wasn’t enough of a challenge, so [repkid] fired up his 3D printer and churned out three smaller Koch vases to serve as “bulbs” for the lamp. Inside, he affixed each LED strip to a laser-cut acrylic housing with clear tape. The three bulbs attach around a wooden base, which also holds a larger, central Koch print at its center. The base also contains a PICAXE 14M2 controller to run the dioder while collecting input from an attached wireless receiver. The final component is a custom control box—comprised of both 3D-printed and laser-cut parts—to provide a 3-dial remote. A simple spin communicates the red, green, and blue values through another PICAXE controller to the transmitter. Swing by his site for a detailed build log and an assortment of progress pictures.

 

Driving 1000 NeoPixels With 1k Of Arduino RAM

timing

NeoPixels, or WS2812 RGB LEDs, are the display device du jour for impressive and blinding lighting projects. Commonly known for very tight timing requirements, [Josh] discovered this is, in fact, usually unnecessary. The timing requirements for NeoPixels aren’t as bad as they seem, once you get to know them.

The official WS2812 timing specs give values that are fairly constraining for anyone writing a library to drive these RGB LED pixels, but simplifying the timing diagram by assuming a 50% duty cycle on the data lines and ignoring the longer maximum times results in a surprising conclusion: the only tight timing parameter for NeoPixel signaling is the maximum width of the 0-bit pulse.

Realizing this, [Josh] wrote a simple demo program to drive over 1000 NeoPixels – an 11 meter long strip – using 1K of RAM on an Arduino. The trick comes by simply delaying the bitbanging a set number of cycles. No obtuse assembly required.

There is only one problem with [Josh]’s method of driving a nearly unlimited amount of NeoPixels – building a display where every NeoPixel is an element in a larger image, such as in a video display, is impossible on systems with limited amounts of RAM. The code writes values to the NeoPixel strip algorithmically, so if you can’t build your animation with for loops, you’re out of luck. Still, Driving this many NeoPixels is a migraine trigger, and we have to give [Josh] credit for doing this with 1K of RAM.

Check out the video of [Josh]’s extreme NeoPixel strip below.

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A Raspi Ambilight With HDMI Input

With the Raspberry Pi now most famously known as a $30 media PC, it only makes sense that the best uses for the GPIO pins on the Pi are used for an Ambilight. [Great Scott Labs] put up a great video on using the Pi as a uniquely configurable Ambilight with Hyperion and just about any video input imaginable.

This isn’t the first Ambilight clone [Great Scott] has put together, but for the first version the Ambilight functioned only under Raspbian and not any random HDMI input. The new version solves this by using an HDMI splitter box, feeding into an HDMI to composite converter, and finally into a USB composite capture dongle attached to the Raspi.

With the software in the instructions, the Raspi effectively mirrors the video coming from the video capture dongle. The Pi is running Hyperion to control a strip of WS2801 RGB LEDs, making the back of any TV glowey and blinkey.

Since [Great Scott] is using a component video signal as an input, the adapters necessary to have any device work with this Ambilight are readily available. We’d honestly like to see this build working with the old Commodore disk access screen border going nuts, so be sure to send that in if you ever get that working.

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Green Light Go, Red Light Come Back Later

LED IM status indicatorDepending on your taste for social interaction and tolerance for distraction, an open floor plan or “bullpen” office might not be so bad with a total of four people. Hackaday.io user [fiddlythings] likes it, but people often stop by to see him or one of his coworkers only to find them busy or absent. While their status is something they could plainly see in Microsoft Communicator from their own desk, some people like to chat in person or stop by on their way to and from meetings.

In order to save these visitors a few seconds, [fiddlythings] came up with an IM status indicator using their existing nameplates outside the door. Each of their names has a little silver dot by it which he backlit with a flattish RGB LED. These LEDs are driven by a Raspberry Pi and NPN transistors through a ribbon cable.

The plan was to imitate the Communicator status colors of green for available, red for busy, and yellow for away. [fiddlythings] dialed up a lovely shade of amber for away using a mix of red and green. Since he really only needs two colors, he’s using eight NPN transistors instead of twelve. The quick ‘n dirty proof of concept version used Python and a Pidgin IM console client called Finch. Once he got IT’s blessing, he implemented the final version in C++ using Libpurple to interface with Communicator.

This isn’t the first time we’ve seen a Pi used to indicate status—remember this mobile hackerspace indicator?

3D Printed RGB LED Bracelet

3dprintedrgbbraclet

[Marcus’s] 3D-printed LED bracelet has moved through a number of revisions recently, but each iteration is impressive in both simplicity and functionality. Inspired to experiment with his print of [nervoussystem’s] Diagrid Bracelet, [Marcus] took the opportunity to add some LEDs with his first build, which combined a strip of RGB LEDs, a small battery, and an Adafruit Trinket microcontroller.

A second build soon followed, which overhauled the bracelet’s design into a more solid form and managed to double the amount of LEDs by upgrading to a different strip. The bracelet is currently in its third revision, cycling through the spectrum for around 3.5 hours on a single charge. This build also sports a 3-axis accelerometer: when the wearer shakes the bracelet, the colors skip around. If shaken long enough, the bracelet will enter a dazzling flurry of color flickering. Stick around after the break for a few demonstration videos. If you want to print your own, head over to [Marcus’s] Thingiverse file.

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The Butt Lamp: Light From Where the Sun Don’t Shine

led-butt

[Trent] is one of those guys who can make things happen. A friend of his gifted him a  mannequin derriere simply because he knew [Trent] would do something fun with it. “Something fun” turned out to be sound reactive LED butt. At first blush, this sounds like just another light organ. This butt has a few tricks up its …. sleeve which warrant a closer look. The light comes from some off the shelf 5050 style RGB LED strip. The controller is [Trent’s] own design. He started with the ever popular MSGEQ7 7 Band Graphic Equalizer Display Filter, a chip we’ve seen before. The MSGEQ7 performs all the band filtering and outputs 7 analog levels corresponding to the amplitude of the input signal in that band. The outputs are fed into an ATTiny84, which drives the RGB strip through transistors.

The ATTiny84 isn’t just running a PWM loop. At startup, it takes 10 samples from each frequency band. The 10 samples are then averaged, and used to create a noise filter. The noise filter helps to remove any ambient sound or distortions created by the microphone. Each band is then averaged and peak detected. The difference between the peak and the noise is the dynamic range for that band. The ATTiny84 remaps each analog sample to be an 8 bit value fitting within that dynamic range. The last step is to translate  the remapped signal values through a gamma lookup table. The gamma table was created to make the bright and dark colors stand out even more. [Trent] says the net result is that snare and kick drum sounds really pop compared to the rest of the music.

Without making this lamp the butt of too many jokes, we’d like to say we love what [Trent] has done. It’s definitely the last word in sound reactive lamps. Click through to see [Trent’s] PCB, and the Butt Lamp in action.

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