3D Spectrum Analyzer uses 1280 LEDs

One of [Dooievriend]’s friends recently pressed him into service to write software for a 3d spectrum analyzer/VU that he made. The VU is a fairly complex build: it’s made up of 1280 LEDs in a 16x16x5 matrix controlled by a PIC32 clocked at 80MHz. [Dooievriend] wrote some firmware for the PIC that uses a variation on a discrete Fourier transform to create a 3D VU effect.

j6v2i When [Dooievriend] set out to design the audio analyzing portion of the firmware, his mind jumped to the discrete Fourier transform. This transform calculates the amplitude in a series of frequency bins in the audio—seemingly perfect for a VU. However, after some more research, [Dooievriend] decided to implement a constant Q transform. This transform is very similar to a Fourier transform, but it takes into account the logarithmic way that the human ear interprets sound.

[Dooievriend] started implementing the constant Q transform using an interrupt-based sampler, but he quickly ran into issues with slow floating-point math on his PIC32 (which doesn’t have a hardware floating-point unit). Thankfully he rewrote his code using fixed-point math, and the transform runs nearly real-time. Check out the video after the break to see the VU in action, and a second video that gives some details on the hardware build.

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Rebraining an LED Marquee with a Spark Trammell Hudson’Core

Wires? Where this LED scroller is going we don’t need wires. Well, except for power but everything needs power. The 90×7 LED marquee hangs over the entrance to NYC Resistor’s laser cutter room. Thanks to a Spark Core and a bit of work from [Trammell Hudson], the sign is working and attached to the network.

The original unit called for an RS485 connection for input. Other than that there wasn’t really a reason it had been collecting dust. Closer inspection of the internals proved that the display is driven exactly as you would expect: transistors for the rows and shift registers for the columns. Well, actually the columns are split into separate shift registers for the even and odd but that doesn’t complicate things too much. GPIO takes the seven row-driving transistors, two shift register clocks, data, latch, and enable for a total of twelve pins.

The Spark Core completely replaces the Atmel 80C32X2 and its RTC by pinging the network for UTC time synchronization once per day.

[via NYC Resistor]

SXSW Create: Sparkfun Gives Kids Awesome Badges to Hack

By far the most desirable booth for the crowds at SXSW Create was the Sparkfun quadrant. We call it a quadrant because they had a huge footprint approaching 1/4 the tented area, but it was well used. They brought a number of staff down to Austin in order to give away a legit electronic badge project they call BadgerHack.

sxsw-sparkfun-badgerhack-kit-thumbWe love badge hacking. LOVE IT! But South-by isn’t purely a hardware conference so the badges aren’t made of PCBs (for shame). Add to that, free entry to Create scores you a wristband but no badge.

This is the answer to that, a badge giveaway and build-off aimed at kids but cool enough to make me feel only slightly awful for accepting one when I pretty much knew they were going to run out before the final day was done.

The USB stick PCB is, as you guessed it, an Arduino compatible loaded up with an FTDI chip and an ATmega328p which they call the BadgerStick. Accompanying this is a multiplexed 8×7 LED matrix board. Solder the three pin headers and the battery holder leads, connect to the plastic badge using the supplied double-stick tape, and you have a badge that scrolls a message in LEDs.

DSC_0508What an awesome giveaway. I really like it that they didn’t cut corners here. First off, the kids will value the badge much more because they had to actually assemble it rather than just being handed a finished widget. Secondly, there is the USB to serial chip and USB footprint that means they can reprogram it without any extra equipment. And an LED matrix… come on that’s just a gateway drug to learning Wiring. Bravo Sparkfun and Atmel for going this route with your marketing bucks.

The badge activity rounded out with some hardware interfacing. There’s a 3-pin socket that attendees could plug into 4 different stations around the booth. Once done they received a coupon code for Sparkfun that scrolls whenever the badge is booted up. For some at-home fun, the writeup (linked at the top) for the BadgerHack firmware is quite good. It offers advice on changing what is displayed on the badge and outlines how to build a game of Breakout with just a bit of added hardware.

Kill Time Making Flappy Bird, Not Playing It

With all the Flappy Bird clones floating around in the ether after the game’s unexpected success, there are some that are better than others. And by better, we mean, hacked together from misc hardware. If you’ve got an Arduino on hand, then you’re half way to making your own:

The “Minimalist” Version

[aron.bordin] created his own Flappy Bird game with a short list of parts some of us likely have lying around on our bench. An Arduino loaded with the appropriate code is wired to a 16×16 LED matrix, which apparently displays the minimal amount of visual information you’d need to play the game. The only other parts required are a single pushbutton and resistor tethered on a breadboard to control your flapping. With the wire hookup laid out by convenient diagrams and the libraries required for the code all found on the same page, this is easily something one could bang out in an afternoon. If afterwards you still find yourself with more time to kill than you can stand to play Flappy Birds, there is always the option of fashioning a humorously-sized cell phone case to squeeze it all into… which we’d like to see.

The “Fancy” Version

If you want more resolution than solid colored LEDs, or you just have a fondness for the terrifying bird abstraction the game is known for, you can switch out the 16×16 matrix for a Nokia LCD screen. [Huy’s] rendition of this build over on Hackaday.io will deliver a “more detailed” graphic for the game, and is still roughly just as easy to assemble. Similarly, an Ardunio is loaded with the smarts required to generate the game, along with a single pushbutton tacked on for control. The code and the daunting (/sarcasm) two steps needed to wire the Arduino to the screen can be found on his project’s page.

If you must kill boredom playing Flappy Bird, there is no excuse not to do so on something you made yourself.

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LED Matrix Infinity Mirror

[Evan] wrote in to let us know about the LED matrix infinity mirror he’s been working on. [Evan] built a sizable LED matrix out of WS2812B LEDs and mounted them to a semi-reflective acrylic sheet, which makes a pretty awesome infinity mirror effect.

Instead of buying pre-wired strands of serial LEDs like we’ve seen in some other projects, [Evan] purchased individual WS2812 LEDs in bulk. Since the LEDs just had bare leads, [Evan] had to solder wires between each of his 169 LEDs (with some help from a few friends). After soldering up hundreds of wires, [Evan] drilled out holes for each LED in a piece of semi-reflective acrylic and inserted an LED into each hole.

To create the infinity mirror effect, [Evan] mounted the LED matrix behind a window. [Evan] put some one-way mirror film on the outside of the window, which works with the semi-reflective acrylic to create the infinity mirror effect. The LEDs are driven by an Arduino, which is controlled by a couple of free programs to show a live EQ of [Evan]’s music along with patterns and other effects.

What is the Matrix…Clock?

We’re surprised we haven’t seen this kind of clock before, or maybe we have, but forgot about it in the dark filing cabinets of our minds. The above picture of [danjhamer’s] Matrix Clock doesn’t quite do it justice, because this is a clock that doesn’t just tick away and idly update the minutes/hours.

matrix clock

Instead, a familiar Matrix-esque rain animation swoops in from above, exchanging old numbers for new. For the most part, the build is what you would expect: a 16×8 LED Matrix display driven by a TLC5920 LED driver, with an Arduino that uses a DS1307 RTC (real-time clock) with a coin cell battery to keep track of time when not powered through USB. [danjhamer] has also created a 3D-printed enclosure as well as added a piezo speaker to allow the clock to chime off customizable musical alarms.

You can find schematics and other details on his Hackaday.io project page, but first, swing down below the jump to see more of the clock’s simple but awesome animations.

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8 Bit Message in a Digital Bottle

As seasoned data-travelers, we’re used to wielding the internet to send messages and communicate to others without any limitations. No one has to be stranded on a figurative island blowing smoke signals… unless of course they wanted to be. What [Harm Alexander Aldick] has done with his project “Lorem Ipsum”, is create a situation where others can only communicate to him through a sort of message in a bottle. The bottle in this case is an electronic widget.

In this social experiment, [Harm] has stationed a small Ikea picture frame at his desk, which shows images and text sent to him in real-time from others in the world. With an Arduino as the brain, a small 8×8 LED matrix mounted at the bottom right of the frame displays the data received by means of an ethernet module. Anyone can use his web interface to modify the pixels of the matrix on a virtual version of the installation. Once sent, the message is transmitted through an IPv6 internet connection and is translated to UDP which the unit is controlled by.

[Harm]’s project investigates how people react when given the chance to send a message in complete anonymity to someone they don’t know… in of all things, the form of something as limited as 64 pixels. The project name “Lorem Ipsum” refers to the filler text used in graphic design to hold the place of what would otherwise be more meaningful information, so that it doesn’t detract from the experience of viewing the layout. Curious about what sort of ‘graphical experience’ I would come up with myself, I took a shot at punching away at [Harm’s] GUI. I got momentarily lost in turning the little red dots on and off and eventually turned out this little ditty:

ipsum1

It was supposed to be something of a triangle, yet turned into a crop circle… or pronged nipple. After it was sent, I wondered whether or not [Harm] actually saw it. In the case that he did, I can only imagine what I communicated to our fellow hacker abroad with my squall of dots. All of these thoughts though are the whole point of the project. Awesome work!