Blue LED Streetlights Keeping You Awake?

If you’ve played around with “white” LEDs, you already know that there’s no such thing. There’s warm white and cool white and any numbers of whites in-between. And when white LEDs were new, the bluer “cool white” variety were significantly more prevalent.

Enough US states have swapped out their old street lights with LEDs that it may be having a measurable effect on people and on the animals around us. This is the claim in a recent position paper by the American Medical Association’s Council on Science and Public Health. (Report as PDF.)

Science strongly suggests that heavy doses of light can keep people from falling asleep, and that brighter LED streetlamps may be making the problem worse. The AMA report goes a step further, and pins extra blame on the color of the light. Blue light apparently suppresses the production of melatonin which helps you sleep at night. And it’s not just humans whose circadian rhythms are getting messed up — the effects are seen throughout the animal kingdom.

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Driving 16 WS2812B Strips with GPIOs and DMA

[Martin Hubáček] wrote in with his WS2812 LED library for the STM32F3 series processors. [Martin]’s library takes the same approach as [Paul Stoffregen]’s OctoWS2811 for the Teensy, and [Erich Styger]’s for the Freescale FRDM-K64F board. That is, it uses three DMA channels to get the signal out as fast as possible.

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LED Bulb-shade Cityscapes

Cost-effective LED lighting for your home has opened up many doors for more efficient living, but also some more creative illumination for your living space. If you want to bring the dazzle of city lights right into your home, [David Grass] has two projects to sate this desire in perhaps the most literal way possible: Huddle and Stalaclights.

These clever, 3D printed bulbshades are possible since LEDs emit very little heat, and can be printed in a variety of designs. Huddle is named for — and illustrates — humanity’s coalescing into cities as the centre of modern life from which most of our information and technology emits. Stalaclights offers an inverted perspective on the straining heights of skyscrapers and is inspired by the Art Deco era and the expansion of cities like New York and Chicago.

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SIM Card Connectors and White PCBs Make Huge LED Snowflakes Happen

[Mike Harrison] talked about designing and building a huge scale LED lighting installation in which PCBs were used as both electrical and mechanical elements, and presented at Electromagnetic Field 2016. The project involved 84,000 RGBW LEDs, 14,000 microcontrollers and 25,000 PCBs. It had some different problems to solve compared to small jobs, but [Mike] shared techniques that could be equally applied to smaller scale projects or applications. He goes into detail on designing for manufacture and assembly, sourcing the parts, and building the units on-site.

The installation itself was a snowflake display for a high-end shopping mall in Hong Kong in the 2015 Christmas season. [Mike] wanted a small number of modular boards that could be connected together on-site to make up the right shapes. In an effort to minimize the kinds of manufacturing and parts needed, he ended up using modular white PCBs as structural elements as well as electrical. With the exception of some minor hardware like steel wire supports, no part of the huge snowflakes required anything outside of usual PCB manufacturing processes to make. The fewer suppliers, the fewer potential problems. [Mike] goes into design detail at 6:28 in the video.

For the connections between the boards, he ended up using SIM card connectors intended for cell phones. Some testing led to choosing a connector that matched up well with the thickness of a 1.6mm PCB used as a spacer. About 28,000 of them were used, and for a while in 2015 it was very hard to get a hold of that particular part, because they had cleaned everyone out! Continue reading “SIM Card Connectors and White PCBs Make Huge LED Snowflakes Happen”

Hackaday Prize Entry: Under Cabinet LED Lighting Controller

[Matt Meerian]’s workbench seems to be in perpetual shadow, so he has become adept at mounting LED strips under all his shelves and cabinets. These solve any problems involving finding things in the gloom, but present a new problem in that he risks a lot of LED strips being left on, and going round turning them all off is tedious.

His solution is to make a wireless controller for all his home LED strips, under the command of a web app from his Android tablet. An ESP8266 and a set of MOSFETs provide the inner workings, and the whole is presented on a very compact and well-designed purple OSH Park PCB reflow soldered on a $20 Wal-Mart hotplate and set in a plastic enclosure. The web interface is still in development, but has a fairly simple CSS front end for the ESP8266 code. All software, the schematic, and BoM can be downloaded from the Hackaday.io page linked above.

This project isn’t going to end world hunger or stop wars, but it’s beautifully done and well documented, and it makes [Matt]’s life a lot easier. And that makes it a good entry for the Hackaday Prize.

Electronic Message In a Bottle

We remember going to grandfather’s garage. There he would be, his tobacco pipe clenched between his teeth, wisps of smoke trailing into the air around him as he focused, bent over another of his creations. Inside of a simple glass bottle was something impossible. Carefully, ever so carefully, he would use his custom tools to twist wire. He would carefully place each lead. Eventually when the time was right he would solder. Finally he’d place it on the shelf next to the others, an LED matrix in a bottle.

led-message-in-a-bottle-assemblyWell, maybe not, but [Mariko Kosaka]’s father [Kimio Kosaka] has done it. In order to build the matrix, he needed tools that could reach inside the mouth of the bottle without taking up too much space to allow for precise movement. To do this he bent, brazed, twisted, and filed piano wire into tools that are quite beautiful by themselves. These were used to carefully bend and position the LEDs, wires, and other components inside the bottle.

Once the part was ready, he used a modified Hakko soldering iron to do the final combination. We wonder if he even had to be careful to solder quickly so as not to build up a residue on the inside of the bottle? The electronics are all contained inside the bottle. One of the bottles contained another impressive creation of his: an entire Arduino with only wire, dubbed the Arduino Skeleton. Batteries are attached to the cork so when the power runs low it can be removed and replaced without disturbing the creation.

It’s a ridiculous labor of love, and naturally, we love it. There’s a video of it in operation as well as one with him showing how it was done which is visible after the break. He showed them off at the Tokyo Maker Faire where they were surely a hit.

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Pressure Plate LED Coasters!

Looking to use up some more of his flexible LED strip, Hackaday alum and Tindie writer [Jeremy Cook] tried for a funky accent to his dinner or coffee table: light up coasters.

Using his CNC router to carve out two pieces of translucent plastic to house four 3V CR2032 batteries, four pieces of LED strip, and some wire, [Cook] had created a pressure plate circuit that activated once a drink is set on it. The original layout of the circuit, however, didn’t work, and the space for the LED strips proved to be too small. A quick redesign and some more time with his router resulted in an almost working product. Initially intending to use screws to secure the coaster, hot glue provided the perfect amount of spring once he had thinned out the coaster top to allow it to more easily flex and complete the circuit.

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