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.

Continue reading “Arduino Drives A 600-Character Display” →

HackIt: Why Aren’t We Hacking On The LED Printer?

February 11, 2020 by Jenny List 54 Comments

Strings of LEDs are a staple of the type of project we see here at Hackaday, with addressable devices such as the WS2812 in particular having changed beyond recognition what is possible on a reasonable budget. They’ve appeared in all kinds of projects, but are perhaps most memorable when used in imaging projects such as screen-like arrays or persistence-of-vision systems. There’s another addressable LED product that we haven’t seen here, which is quite a surprise considering that it can be found with relative ease in junk piles and has been on the market for decades. We’re talking about the LED printer, and the addressable LED product in question is a very high density array of LEDs the width of a page, designed to place an image of the page to be printed on the toner transfer drum.

Continue reading “HackIt: Why Aren’t We Hacking On The LED Printer?” →

Fake That Fireplace Flicker With Flame Bulbs

February 10, 2020 by Kristina Panos 9 Comments

Ask anyone who’s ever tuned into Fireplace TV on a cold winter’s night — even though you can’t feel the heat or roast a marshmallow with it, fake fire is almost as soothing as the real thing. And if you have kids or pets, it’s a whole lot safer. But why go to the expense of buying a lighted insert when you could just make your own?

You don’t even need to get fancy with a microcontroller and RGB LEDs, either — just do what [Ham-made] did and dismantle some LED flame bulbs. They already have everything you need, and the flex PCB makes them easy to work with.

[Ham-made] adhered three bulbs’ worth to a piece of foam board with double-stick tape, soldered all the leads together, and wired in a toggle switch and a 2xAA battery pack. The bulbs each had a tilt switch so that the “flames” flow upward regardless of orientation, but [Ham-made] removed those to avoid flickering connectivity and fights with the toggle switch.

Once it was all wired up, [Ham-made] hot-glued some magnets to the foam board and attached it to the underside of the grate to keep it safe from the logs and the ash pit, while still allowing the glow to emanate from the right spot for realism. The only thing missing are the crackles and pops, and [Ham-made] is burning to hear your implementation ideas.

[Ham-made] wasn’t using his fireplace in the traditional way because the house is smallish and centrally heated. But if you rely on yours to keep you warm and cozy, why not make it voice-activated?

Huge Seven Segment Display Made From Broken Glass

February 10, 2020 by Tom Nardi 12 Comments

A staple of consumer devices for decades, seven segment displays are arguably one of the most recognizable electronic components out there. So it’s probably no surprise they’re cheap and easy to source for our own projects. But that doesn’t mean there isn’t room for personal interpretation.

[MacCraiger] wanted to build a wall clock with the classic seven segment LED look, only his idea was to make it slightly larger than average. With RGB LED strips standing in for individual LEDs, scaling up the concept isn’t really a problem on a technical level; the tricky part is diffusing that many LEDs and achieving the orderly look of a real seven segment display.

All those segments perfectly cut out of a sheet of plywood come courtesy of a CNC router. Once the rectangles had been cut out, [MacCraiger] had to fill them with something that could soften up the light coming from the LEDs mounted behind them. He decided to break up a bunch of glass bottles into small chunks, lay them inside the segments, and then seal them in with a layer of clear epoxy. The final look is unique, almost as though the segments are blocks of ice.

At first glance the use of a Raspberry Pi Zero to control the LED strips might seem overkill, but as it turns out, [MacCraiger] has actually added in quite a bit of extra functionality. The purists might say it still could have been done with an ESP8266, but being able to toss some Python scripts on the Linux computer inside your clock certainly has its appeal.

The big feature is interoperability with Amazon’s Alexa. Once he tells the digital home assistant to set an alarm, the clock will switch over to a countdown display complete with digits that change color as the timer nears zero. He’s also written some code that slowly shifts the colors of the digits towards red as the month progresses, a great way to visualize at a glance how close you are to blowing past that end of the month deadline.

We’ve seen something of a run on custom multi-segment displays recently. Just last month we saw a clock that used some incredible 25-segment LED displays, complete with their own unique take on the on epoxy-filled diffusers.

Continue reading “Huge Seven Segment Display Made From Broken Glass” →

Lightbulb Glows When You Have That Eureka Moment

February 8, 2020 by Lewin Day 9 Comments

We’re not entirely sure where the lightbulb-idea concept came from, but it’s a cultural touchstone rapidly becoming outmoded by the prevalence of compact fluorescent and LED lighting. Despite this, [Alex Glow] and [Moheeb Zara] whipped up the Prometheus Lamp to let you experience it for real.

The build starts with a glass lightbulb souvenir from the Neon Museum in Las Vegas. Inside, a TinyLily Mini microcontroller board is tasked with talking to an accelerometer to detect movement. When the lightbulb is picked up and oriented in the vertical axis, it lights up a NeoPixel LED, glowing to indicate that you’ve just had a remarkable idea! It’s all powered off a single CR2032 coin cell, thanks to the low voltage requirements of the modern TinyLily components.

It’s a build that serves as a good way to learn about accelerometers, and it makes a fun desk toy, too. We’ve seen some other projects go by the name “Prometheus”, too — like a wrist mounted flame thrower. How’s that for variety?

Lighting Up Your Spectrespecs

February 5, 2020 by Lewin Day 5 Comments

In the ever-popular world of Harry Potter, a pair of Spectrespecs are useful if you’re hunting for wrackspurts and nargles. While we’ve never spotted either of these creatures ourselves, if you’d like to go out on a hunt, [Laveréna]’s build might be for you.

To start with, you’ll need the frames for the Spectrespecs. [Laveréna] elected to source hers commercially, but you can 3D print them or even craft them by hand if you so desire. Then, a TinyLily microcontroller board is installed, with its small size allowing it to be tucked neatly out of sight in the top of the sunglasses. Two NeoPixels are then installed, with the TinyLily programmed to flash the LEDs in the requisite blue and red colors for easy identification of supernatural creatures.

Tools such as cheap microcontrollers designed for wearables and low-cost addressable LEDs are making advanced cosplay designs easier than ever. Whipping up custom blinkables no longer requires knowledge of advanced multiplexing techniques and how to properly drive high-power LEDs. Of course, LED wearables do still get properly advanced – like this skin-based 7-segment display. If you’ve got a glowable project of your own that you’re dying to share, be sure to let us know!

Art Imitates DNA

February 1, 2020 by Al Williams 8 Comments

It has recently been possible to pay a service a little bit of money and learn more about your own DNA. You might find out you really aren’t Italian after all or that you are more or less susceptible to some ailments. [Paul Klinger] had his DNA mapped and decided to make a sculpture representing his unique genetic code. The pictures are good, but the video below is even better.

The project requires a DNA sequencing, a 3D printer, and a Raspberry Pi Zero. Oh, you can probably guess you need a lot of RGB LEDs, too. Of course, the display doesn’t show the whole thing at one time — your DNA pattern scrolls across the double helix.

Continue reading “Art Imitates DNA” →