We all love seeing data represented in pretty ways — whether it’s necessary or not. Take VU meters for example. They’re a super useful tool for audio editors to balance signals, but they also look really cool, even if you’re only listening to music. Who didn’t use a Winamp skin with a built-in VU meter back in the day? Even after the demise of everyone’s favorite media player, we still see these great graphs popping up all over the place.
Most recently, we’ve seen VU meters circle back around to have a bit of a retro vibe in this awesome Arduino-controlled LCD VU meter built by [mircemk]. Based on the KTAudio VU Meter project, it features an ultra-wide LCD, audio input, and volume knob, all tidily wrapped up in a case whose color scheme that can only conjure images of the famed Altair 8800, or an old Tektronix oscilloscope. The LCD itself is fairly responsive — but you can judge for yourself in the video below. The signature fading that so commonly accompanies screen refreshes on LCDs such as this one really adds to the retro effect.
You may just need one of these displays on your desk — after all, while you may not need to know how loud each audio channel is, don’t you at least want the information available? Just in case. Bar graph display a bit too modern-looking for you? Well then you should check out [mircemk]’s OLED version that displays dual analog meters.
Looking for a digital recreation of the classic analog volume unit (VU) meter? If you’ve got an Arduino, a few passive components, and a SSD1306 OLED, then [mircemk] might have the answer for you. As you can see in the video below, his code turns a handful of cheap parts into an attractive and functional audio display.
The project’s Hackaday.IO page explains that the idea is based on the work of [stevenart], with code adapted for the SSD1306 display and some tweaks made to the circuit. While [mircemk] says the code could be modified for stereo as long as the two displays don’t have conflicting I2C addresses, he decided to simply duplicate the whole setup for each channel to keep things simple. With as cheap as some of these parts are nowadays, it’s hard to blame him.
[mircemk] has provided source code for a couple different styles of VU indicators, the colors of which can easily be inverted depending on your tastes. He also clarifies that the jerky motion of the virtual “needle” seen in the video is due to the camera; in real-life it sweeps smoothly like the genuine article.
When we think of 3D printed parts for our projects, most of us imagine little bits like brackets and mounting plates. Perhaps the occasional printed project enclosure. But if you’ve got a big custom printer as [Joshendy] does, plus plenty of time, it opens up a whole new world of large scale projects. Take for example the gorgeous RGB LED guitar body he recently completed.
Despite the considerable 300 x 300 mm build area of his custom 3D printer, [Joshendy] still had to design the guitar body in sections that could be bolted together after being printed in ABS. It took around 60 hours to run off all the parts, with the large central section taking the longest to print at 28 hours. With the generous application of heat-set inserts, the assembled guitar should be plenty strong.
While the skeletal plastic body of the guitar is certainly visually interesting in itself, it only makes up for half of the final look. Inside the central cavity, [Joshendy] has embedded two strips of RGB LEDs, a 128×64 OLED screen, and a custom PCB that plays host to a STM32L4 microcontroller the appropriate voltage regulators necessary to run it all on a battery pack.
The board taps into the audio being produced by the guitar and uses a fast Fourier transform (FFT) to get the LEDs reacting to the beat. As demonstrated in the video after the break, you can use the screen to navigate through the different lighting modes in real-time right on the instrument itself.
[Sam Kent] and friends built a sound-reactive LED display as part of the Leeds (UK) Digital Festival and exhibited it at Hyde Park Book Club. The installation consists of a grid of 25 tubes, each one made out of four recycled 2-liter bottles equipped with a string of a dozen WS2812B LEDs controlled by a central Arduino.
Connected to the Arduino via USB, a computer running a Processing application analyzes the audio input and tells the Arduino which LEDs to light and when. The red tube in the center responds to bass, the ring of yellow LEDs mids, and the outer ring glows blue in response to high frequencies.
It’s amazing how just a simple 2-liter makes a rather effective light pipe to amplify the effect of each burst of color. We think this installation would be a great addition to the magnificent LED dance floor we recently looked at from our friends up in Toronto. If you seek an LED art piece that’s a lot easier to move around, what you’re after is a rave shopping cart.
We’ve seen a lot of builds using electroluminescent wire, usually in the realm of costumes and props. Unfortunately, most electrical engineers don’t deal with blinking and dimming EL wire and panels and any tinkerer trying to control electroluminescence doesn’t have a lot of resources on how to control EL stuff. [ch00f] wanted to fill this knowledge gap, so he build a sound reactive EL panel driver and learned a lot in the process.
Nobody really knows how electroluminescent wire and panels work on a molecular level, but [ch00f] did know that changing the direction of an electric field will cause the EL material to glow. Changing the frequency of this electric field will change the EL material’s brightness, so all [ch00f] had to do was make a variable-frequency EL driver – something that’s a lot harder than it sounds.
We won’t bore you with the details because we couldn’t do [ch00f]’s write up any justice. We will skip to the end and tell you [ch00f] was able to make a sound reactive EL panel after a month of work that included making his own transformers and doing a whole bunch of math. You can check out the video of [ch00f]’s [Tony Stark]-esque EL panel after the break.
[Jonathan Thomson] was ruminating on EL wire displays and decided that most he has seen are boring, static fixtures or installations that simply flash EL wire on and off at a fixed rate. He thought that EL wire has far more potential than that, and set off to build something more exciting. Using a graphic equalizer T-shirt, with which we’re sure you are familiar, he put together a slick, sound-reactive EL wire display.
He started off by removing the EL panel and inverter from the aforementioned T-shirt, separating the display into two pieces. He set aside the panel and focused on wiring up the inverter’s ribbon cable to a set of EL wire strands he picked up for the project. Once he had everything hooked up, he put a design together on a cardboard box, which he intended to use for wrapping Christmas presents. With the holiday behind him, [Jonathan] broke down his original display and constructed another to offer up some fun birthday wishes.
While the EL inverter was originally built to display sounds detected by an onboard mic, [Jonathan] added a 3.5” stereo jack to his so that he can feed audio directly into the display using an MP3 player.
Continue reading to see the EL display in action, and be sure to check out his writeup if you are looking to spice up your gift giving this year.