Slack Off From Home With A Networked Jam Session

August 26, 2020 by Kristina Panos 6 Comments

Those of you who were regular office dwellers before the pandemic: do you miss being with your coworkers at all? Maybe just a couple of them? There’s only so much fun you can have through a chat window or a videoconference. Even if you all happen to be musicians with instruments at the ready, your jam will likely be soured by latency issues.

[Eden Bar-Tov] and some fellow students had a better idea for breaking up the work-from-home monotony — a collaborative sequencer built for 2020 and beyond. Instead of everyone mashing buttons at once and hoping for the best, the group takes turns building up a melody. Each person is assigned a random instrument at the beginning, and the first to go is responsible for laying down the beat.

Inside each music box is an ESP8266 that communicates with a NodeRed server over MQTT, sending each melody as a string of digits. Before each person’s turn begins, the LED matrix shows a three second countdown, and then scrolls the current state of the song. Your turn is over when the LED strip around the edge goes crazy.

Music can be frustrating if you don’t know what you’re doing, but this instrument is built with the non-musician in mind. There are only five possible notes to play, and they’re always from the same scale to avoid dissonance. Loops are always in 4/4, which makes things easy. Players don’t even have to worry about staying in time, because their contributions are automatically matched to the beat. Check it out after the break.

Tired of sitting indoors all day, but still want to make music? Build a modular synth into a bike and you’ve solved two problems.

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Unique LED Display Inspired By Fighter Jet Dashboard

August 22, 2020 by Tom Nardi 6 Comments

Last year, [Mangy_Dog] was asked by a few friends to consult on a project they were working on. The goal was to build an authentic replica of an F-18 cockpit, apparently for the purposes of creating a film. The project never materialized, but it did inspire him to take a hard look at the 1970s era alphanumeric displays utilized in the real aircraft. One thing lead to another, and he ended up using his own take on the idea to build his own “starburst” digit display.

As [Mangy_Dog] explains, while the faces of these original displays might have been quite small, there was a lot going on behind the scenes. Due to the technical limitations of the time, each alphanumeric character was made up of an array of incandescent light bulbs and fiber optic cables. This worked well enough, but was bulky and complex to manufacture.

Today, we can do better, even on the hobbyist level. As it turns out, 0402 LEDs are just about the right size to recreate the segments of the original starburst displays. So [Mangy_Dog] came up with a simple PCB design to not only align the LEDs properly, but drive them with a 74HC595 shift register and an array of MOSFETs. While assembly wasn’t without its challenges, he made good use of his custom built reflow oven to get all the diminutive components in place.

He went through a few different ideas for the diffuser, but eventually settled on black plastic with tiny holes drilled through courtesy of his laser cutter. Behind each set of three holes is a small pocket that got filled from both sides with transparent UV resin, which was then sanded down after curing. The end result isn’t perfect as you can still tell the center dot is brighter than its peers, but the overall effect is still very nice and definitely has a sort of faux-retro appeal.

The military naturally has access to some incredible technology, though they have a tendency to hold onto it for decades. That an individual with a meager budget and homemade tools can improve upon a piece of hardware installed in a $60+ million airplane is a testament to just how fast things are moving.

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Cakeday Countdown Clock Is A Sweet Little Scroller

July 8, 2020 by Kristina Panos 2 Comments

If you want strangers to give you well wishes on your birthday out in the real world, you have call attention to the occasion by wearing a pointy hat or a button that says ‘today is my birthday, gimme presents’. But on your reddit cakeday, aka the day you joined, you’re automatically singled out with the addition of a slice of 8-bit cake next to your username. The great thing about your cakeday is that you’re almost guaranteed to get some karma for once, especially if you make something cakeday related like [ScottyD]’s cakeday countdown clock. But plenty of people forget what their cakeday is and miss out on the fun.

This countdown clock works like you might expect — every day that isn’t your cakeday, a message scrolls by with the number of days remaining until your next one. When the big day comes, the message becomes TODAY IS YOUR CAKE DAY. Both messages are bookended by cute little pixelated cake slices that we would apply liberally to the day-of message if we made one of these.

This simple but fun project shouldn’t put too big of a dent in your parts box, since it’s essentially an Arduino, a real-time clock module, and a 32×8 LED matrix to display the text. We love the uni-body design of the enclosure because it creates a shelf for the Arduino and gives easy access for gluing in the display from the rear. If for some reason you don’t reddit, then make one anyway and use it to count down to your IRL birthday or something. We’ve got the build video cut and plated for you to consume after the break.

We would understand if 2020 is supplying you with enough existential crises, but if not, consider building a clock that counts down the rest of your life expectancy.

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Rolling Your Own LED Matrix Driver, With Copper Foil Tape To The Rescue

May 30, 2020 by Donald Papp 1 Comment

It all started when [Damien Walsh] got his hands on some surplus LED boards. Each panel contained 100 mini-PCBs hosting a single bright LED that were meant to be to be snapped apart as needed. [Damien] had a much better idea: leave them in their 20×5 array and design a driver allowing each LED to be controlled over WiFi. He was successful (a brief demo video is embedded down below after the break) and had a few interesting tips to share about the process of making it from scratch.

The first hurdle he ran into was something most of us can relate to; it’s difficult to research something when one doesn’t know the correct terms. In [Damien]’s case, his searches led him to a cornucopia of LED drivers intended to be used for room lighting or backlights. These devices make a large array of smaller LEDs act like a single larger light source, but he wanted to be able to individually address each LED.

Eventually he came across the IS32FL3738 6×8 Dot Matrix LED Driver IC from ISSI which hit all the right bases. Three of these would be enough to control the 100-LED panel; it offered I2C control and even had the ability to synchronize the PWM of the LEDs across multiple chips, so there would be no mismatched flicker between LEDs on different drivers. As for micontroller and WiFi connectivity, we all have our favorites and [Damien] is a big fan of Espressif’s ESP32 series, and used the ESP32-WROOM to head it all up.

LED pads bridged to copper tape, with Kapton (polyimide) tape insulating any crossovers.

The other issue that needed attention was wiring. Each of the LEDs is on its own little PCB with handy exposed soldering pads, but soldering up 100 LEDs is the kind of job where a little planning goes a long way. [Damien] settled on a clever system of using strips of copper tape, insulated by Kapton (a super handy material with a sadly tragic history.) One tip [Damien] has for soldering to copper tape: make sure to have a fume extractor fan running because it’s a much smokier process than soldering to wires.

A 3D-printed baffle using tracing paper to diffuse the light rounds out the device, yielding a 20 x 5 matrix of individually-controlled rectangles that light up smoothly and evenly. The end result looks fantastic, and you can see it in action in the short video embedded below.

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Jumbo LED Matrix Brings Classic Sprites To Life

May 18, 2020 by Tom Nardi 9 Comments

Despite all the incredible advancements made in video game technology over the last few decades, the 8-bit classics never seem to go out of style. Even if you weren’t old enough to experience these games when they were new, it’s impossible not to be impressed by what the early video game pioneers were able to do with such meager hardware. They’re a reminder of what can be accomplished with dedication and technical mastery.

The grid has been split up for easier printing.

If you’d like to put a little retro inspiration on your desk, take a look at this fantastic 16 x 16 LED matrix put together by [Josh Gerdes]. While it’s obviously not the only thing you could use it for, the display certainly seems particularly adept at showing old school video game sprites in all their pixelated glory. There’s something about the internal 3D printed grid that gives the sprites a three dimensional look, while the diffused glow reminds us of nights spent hunched over a flickering CRT.

The best part might be how easy it is to put one of these together for yourself. You’ve probably got most of what you need in the parts bin; essentially it’s just a WS2812B strip long enough to liberate 256 LEDs from and a microcontroller to drive them. [Josh] used an Arduino Nano, but anything compatible with the FastLED library would be a drop-in replacement. You’ll also need a 3D printer to run off the grid, and something to put the whole thing into. The 12×12 shadowbox used here looks great, but we imagine clever folks such as yourselves could make do with whatever might be laying around if you can’t nip off to the arts and crafts store right now.

Beyond looking great, this project is a fantastic reminder of how incredibly handy WS2812 LEDs really are. Whether you’re recreating iconic game sprites or fashioning your own light-up sunglasses, it’s hard to imagine how we managed before these little wonders hit the scene.

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LEGO My Colorful Custom Clock

March 23, 2020 by Kristina Panos 7 Comments

[Sofia] spent a lot of time looking around for the perfect LEGO clock. Eventually, she realized that the perfect LEGO clock is, of course, the one you build yourself. So if you find yourself staring at the same old boring clock, contemplating time and the meaning of time itself, why not spend some time making a new timepiece?

You probably already had the LEGO out (no judgment here). This build doesn’t take a whole lot of building blocks — just a microcontroller, a real-time clock module, some LED matrices to display the digits, shift registers if they’re not already built into the matrices, and a pair of buttons for control. [Sofia] used an Arduino Nano, but any microcontroller with enough I/O ought to work. Everybody needs a colorful new way to block out their time.

We love the way this clock looks, especially the transparent panels in front of the LED panels. Given the countless custom pieces out there from all the special sets over the years, we bet you could come up with some really interesting builds.

If your kid is too young to tell time, try building a kid-friendly clock to give them segmented structure.

Via r/duino

Arduino Drives A 600-Character Display

February 14, 2020 by Al Williams 7 Comments

[Peterthinks] admits he’s no cabinet maker, so his projects use a lot of hot glue. He also admits he’s no video editor. However, his latest video uses some a MAX7219 to create a 600 character scrolling LED sign. You can see a video of the thing, below. Spoiler alert: not all characters are visible at once.

The heart of the project is a MAX7219 4-in-1 LED display that costs well under $10. The board has four LED arrays resulting in a display of 8×32 LEDs. The MAX7219 takes a 16-bit data word over a 10 MHz serial bus, so programming is pretty easy.

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