What’s more fun than individually addressable RGB LEDs? Many, many individually addressable RGB LEDs. What’s more fun than all the miscellaneous soldering involved in connecting many of these cheap and cheerful strips together? Well, basically anything. But in particular, these little widgets that [todbot] designed help make connecting up strips of RGB LEDs a snap.
[todbot]’s connectors aren’t particularly groundbreaking, but they’re one of those things that you need the moment you first lay eyes on them. And they’re a testament to rapid prototyping: the mounting holes and improved routing patterns evolved as [todbot] made some, soldered them up, mounted them, and then made some more. We’d like to see some odd angles, of course, but that shouldn’t be too hard to arrange. Everything is up on GitHub, so you can go check it out.
Of course, necessity is the mother of invention, and she’s got many kids. Which is to say that we’ve seen a variation of this hack before precisely because other folks have stared at this matrix-of-strips problem before and come up with similar solutions. Still, we really like the mounting holes and overall aesthetic of [todbot]’s solution, and if you ever find yourself joining WS2812 strips together, give it a try.
It is so often the case with a particular technological advance, that it will be invented almost simultaneously by more than one engineer or scientist. People seem to like a convenient tale of a single inventor, so one such person is remembered while the work of all the others who trod the same path is more obscure. Sometimes the name we are familiar with simply managed to reach a patent office first, maybe they were the inventor whose side won their war, or even they could have been a better self-publicist.
When there are close competitors for the crown of inventor then you might just have heard of them, after all they will often feature in the story that grows up around the invention. But what about someone whose work happened decades before the unrelated engineer who replicated it and who the world knows as the inventor? They are simply forgotten, waiting in an archive for someone to perhaps discover them and set the record straight.
Meet [Oleg Losev]. He created the first practical light-emitting diodes and the first semiconductor amplifiers in 1920s Russia, and published his results. Yet the world has never heard of him and knows the work of unrelated American scientists in the period after the Second World War as the inventors of those technologies. His misfortune was to born in the wrong time and place, and to be the victim of some of the early twentieth century’s more turbulent history.
[Oleg Losev] was born in 1903, the son of a retired Russian Imperial Army officer. After the Russian Revolution he was denied the chance of a university education, so worked as a technician first at the Nizhny Novgorod Radio laboratory, and later at the Central Radio Laboratory in Leningrad. There despite his relatively lowly position he was able to pursue his research interest in semiconductors, and to make his discoveries.
Don’t watch [Jason Hotchkiss]’s video if flashing lights or bleepy-bloopy synthesizer noises give you seizures. Do watch, however, if you’re interested in a big honeycomb-shaped LED matrix being driven at audio frequencies through a dedicated square-wave synthesizer that’s built in.
The LED panel in question is housed in a snazzy laser-cut, honeycomb-shaped bezel: a nice change from the standard square in our opinion. The lights are 1/2 watt (whoa!) whites, and the rows and columns are driven by transistor drivers that are in turn controlled by shift registers. We’re not entirely sure how the matrix is driven — we’d love to see a circuit diagram — but it looks like it’s some kind of strange, non-scanning mode where all of the column and row drives are on at once. Whatever, it’s art.
And it’s driven by logic chips making audio-frequency square waves. Two of these are fed into an LFSR and into an R-2R DAC and then into the shift registers. The output is chaos, but the audio and the visuals do seem to influence each other. It’s an audio-visual embodiment of some of my wildest Logic Noise fantasies. Pretty cool. Enjoy the video.
Hardly a week goes by that some Hackaday post doesn’t elicit one of the following comments:
That’s stupid! Why use an Arduino when you could do the same thing with a 555?
That’s stupid! Why use a bunch of parts when you can use an Arduino?
However, we rarely see those two comments on the same post. Until now. [ZHut] managed to bring these two worlds together by presenting how to make an Arduino blink an LED in conjunction with a 555 timer. We know, we know. It is hard to decide how to comment about this. You can consider it while you watch the video, below.
[nolobot] and his bother struggled with setting up and squaring-off the t-slotted, extruded aluminium frame which makes up the desk. He recommends practicing with a smaller frame for anyone else attempting a similar build. The surface of the desk has a few inches between the polycarbonate top and the 1/4″ plywood painted black serving as the substrate for the LEDs. Those LEDs come in strip form but still required several hundred solders, and wiring headaches in an attempt to make future upgrades manageable. Dozens of support bolts with adjustable feet support the desk surface throughout. These all had to be individually adjusted and can be made out if you look closely at the demo videos.
An Arduino Mega controls the LEDs with the help of the FastLED library. Custom code was necessary because one of the major issues [nolobot] faced was the power draw. 1200 LEDs at 5V draw quite a bit of current, so the LEDs were coded to peak at about 50% brightness. The matrix was split into different banks, while also limiting the 40A PSU to only 15A.
Settle back and watch [mitxela]’s miniature wizardry in the video below, but be forewarned: it runs 36 minutes. Most of the video is necessarily shot through a microscope where giant fingers come perilously close to soldering iron and razor blade.
The heart of the project is an ATtiny9, a six-legged flea of a chip. The flexible PCB is fabricated from Pyralux, which is essentially copper-clad Kapton tape. [Mitxela] etched the board after removing spray-paint resist with a laser engraver – an interesting process in its own right.
After some ridiculously tedious soldering, the whole circuit wraps around a CR927 battery and goes into a custom aluminum and polypropylene case, which required some delicate turning. Hung from off-the-shelf ear hooks, the 12 multiplexed LEDs flash fetchingly and are sure to attract attention, especially of those who know Morse.
You can tell from looking around his workshop that [Paul Jackman] likes plywood even more than we do. And for the bases of these lamps, he sandwiches enough of the stuff together that it becomes a distinct part of the piece’s visuals. Some work with a router and some finishing, and they look great! You can watch the work, and the results, in his video embedded below.
The plywood bases also hide the electronics: a transformer and some LEDs. To make space for them in the otherwise solid blocks of wood, he tosses them in the CNC router and hollows them out. A little epoxy for the caps of the jars and the bases were finished. Fill the jars with colored glass, and a transparent tube to allow light all the way to the top, and they’re done.