For all the hustle and bustle of the holiday season, people still find ways to make time for their passions. In the lead up to Christmas, [Edwin Mol] and a few co-workers built themselves an LED Christmas tree that adds a maker’s touch to any festive decor.
Before going too far, they cut out a cardboard mock-up of the tree. This an easy step to skip, but it can save headaches later! Once happy with the prototype, they printed off the design stencils and cut the chunks of clear acrylic using power tools — you don’t need a laser cutter to produce good stuff — and drilled dozens of holes in the plastic to mount LEDs, and run wires.
A Raspberry Pi 3 and Arduino Uno make this in league with some pretty smart Christmas trees. MAX6968 5.5V constant-current LED driver chips and MOFSETs round out the control circuit. During the build, the central LED column provided a significant challenge — how often do you build a custom jig to solder LEDs? That done, it’s time for a good ol’-fashioned assembly montage! The final product can cycle through several different lighting animations in a rainbow of colours — perfect for a festive build. Continue reading “A Clear Christmas Tree Means More Lights!”
We know, we know — yet another Nixie clock. But really, this one has a neat trick: an easy to use, feature packed driver for Nixies that makes good-looking projects a snap.
As cool as Nixies are — we’ll admit that to a certain degree, familiarity breeds contempt — they can be tricky to integrate. [dekuNukem] notes that aside from the high voltages, laying hands on vintage driver chips like the 7441 can be challenging and expensive. The problem was solved with about $3 worth of parts, including an STM32 microcontroller and some high-voltage transistors. The PCBs come in two flavors, one for the IN-12 and one for the IN-14, and connections for the SPI interface and both high- and low-voltage supplies are brought out to header pins. That makes the module easy to plug into a motherboard or riser card. The driver supports overdriving to accommodate poisoned cathodes, 127 brightness levels for smooth dimming, and a fully adjustable RBG backlight under the tube. See the boards in action in the video below, which features a nicely styled, high-accuracy clock.
From Nixie tachs to Nixie IoT clocks, [dekuNukem]’s boards should make creative Nixie projects even easier. But if you’re trying to drive a Nixie Darth Vader, you’re probably on your own.
If you’re looking for a home hub to display weather, time, and important family information, the formula is pretty simple: build yet another “magic mirror” project. We’re not complaining — magic mirrors look great. But if all you need is time and weather, this elegant pixel display is something just a little bit different.
Among his many criteria for the perfect hack, [Dominic] lists usefulness, visual appeal, and low cost. We’ll agree that his minimalist weather clock hits all those marks, and with the careful selection of a 16 x 32-pixel RGB display module, [Dominic] ended up giving back to the community by developing an Arduino driver for it. He points out that strips of Neopixels could have been used for the display, but they’d have ended up costing more, so the LED matrix was a sensible choice. A 3D-printed separator grid and a paper diffuser provide the proper pixelated look, and some simple animated icons display the two-day weather forecast. We find the time and temperature numerals a little hard to read, but it’s not bad considering the limited resolution of the display. And the case is a nice bit of woodworking too. Not a bad result for only €43.
We’re intrigued by the P10 LED matrix module [Dominic] used for this one. It might be a good choice for a word clock and weather station, or with his driver, a display for just about anything.
How often after being exposed to Star Wars did you dream of having your own working lightsaber? These days — well, we don’t quite have the technology to build crystal-based weapons, but tailor-made lightsabers like redditor [interweber]’s are very much real.
Piggybacking off the Korbanth Graflex 2.0 kit — a sort of bare-bones lightsaber ready to personalize — [interweber] is using a Teensy 3.5 to handle things under the hilt. Instead of taking the easy route and cramming everything into said handle, a 3D printed a cradle for the electronics and speaker keep things secure. The blade is made up of two meters of APA102 LEDs.
As well as all the sound effects appropriate to ‘an elegant weapon for a more civilized age’, a cluster of buttons handle the various functions; , playing and cycling through music(more on that in a second), changing the color of the lightsaber — Jedi today, Sith tomorrow — enabling a flickering effect that mimics Kylo Ren’s lightsaber, color cycling, and a…. rave mode?
Continue reading “A Lightsaber, With Rave Mode”
You think you like RGB LEDs? Columbus, OH art professor [Matthew Mohr] has more blinkenlove than you! His
airport– convention-center-scale installation piece is an incredible 850,000 RGB LEDs wrapped around a 14-foot tall face-shaped sculpture that projection-maps participants’ faces onto the display. To capture images, there is also a purpose-built room with even illumination and a slew of Raspberry Pi cameras to take pictures of the person’s face from many angles simultaneously.
Besides looking pretty snazzy, the scale of this is just crazy. For instance, if you figure that the usual strip of 60 WS2812s can draw just about 9.6 watts full on, that scales up to 136 kW(!) for the big head. And getting the control signals right? Forgeddaboutit. Prof. [Mohr], if you’re out there, leave us some details in the comments.
(Edit: He did! And his website is back up after being DOSed. And they’re custom LEDs that are even brighter to compete with daylight in the space.)
What is it with airports and iconic LED art pieces? Does anyone really plan their stopovers to see public art? How many of you will fly through Columbus on purpose now?
When you need to quantify the color of an object, you’ve got quite a few options. You can throw a Raspberry Pi camera and OpenCV at the problem and approach it through software, or you can buy an off-the-shelf RGB sensor and wire it up to an Arduino. Or you can go back to basics and build this reflective RGB sensor from an LED and a photocell.
The principle behind [TechMartian]’s approach is simplicity itself: shine different colored lights on an object and measure how much light it reflects. If you know the red, green, and blue components of the light that correspond to maximum reflectance, then you know the color of the object. Their sensor uses a four-lead RGB LED, but we suppose a Neopixel could be used as well. The photosensor is a simple cadmium sulfide cell, which measures the intensity of light bouncing back from an object as an Arduino drives the LED through all possible colors with PWM signals. The sensor needs to be white balanced before use but seems to give sensible results in the video below. One imagines that a microcontroller-free design would be possible too, with 555s sweeping the PWN signals and op-amps taking care of detection.
And what’s the natural endpoint for a good RGB sensor? A candy sorter, or course, of which we have many examples, from the sleek and polished to the slightly more hackish.
Continue reading “Color Sensor from an RGB LED and a Photocell”
[Krazer], a post-doctoral researcher at MIT, loves him some lasers. When out of boredom one afternoon he hatched an idea for a laser projector, it grew until a few years later he wound up with this RGB laser for a projector — Mark IV no less.
In addition to 3D-printing the parts, the major innovation with this version is the ability to re-align the lasers as needed; tweaking the vertical alignment is controlled by a screw on the laser mounts while the horizontal alignment is done the same way on the mirror mounts. This simplifies the design and reduces the possibility of part failure or warping over time. An additional aluminium base epoxied to the projector aims to keep the whole from deforming and adds stability. With the help of a mirror for the final alignment — sometimes you must use what you have— the projector is ready to put on a show.
True to the spirit of the art [Krazer] used all open source software for this iteration, and sharing his designs means you can build your own for around $200. As always with lasers take extra precautions to protect your eyes! This 200mW setup is no joke, but that doesn’t mean fun and games are out of the question.