Blooming Flower Lamp Will Test Your 3D Printer

[ossum] has a baby on the way. He admits that he got a bit carried away, brimming with parental excitement. What resulted is a fully articulated LED WiFi lamp that blooms and glows dramatically in the friendly confines of the oncoming baby’s room.

We’ve covered [ossum]’s work before. As usual, he started off by showing his complete mastery of Fusion360 and making the rest of us look bad. If you want to learn 360, we recommend scrobbing through his models to see how it’s done.  The base encloses an ESP8266 and a hobby servo. A clever mechanism pulls down on a stranded steel cable that runs through the stem along with some control lines for the LEDS. This opens and closes the petals. The LEDs are all held in a 3D printed frame which produces a nice even glow.

If you’d like to build one yourself, there’s a full video viewable after the break. Files are available on Thingiverse. Just make sure you tune up your printer first, this is a tough one.

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DIY Plant LED Light Prototype Lights Up The Winter

With winter on the way, our thoughts turn to indoor hacks. And what could be better in the cold winter than fresh veggies? This can be done by replacing the sun with an LED light, and [Margaret Johnson], aka [Bitknitting] has been working on building her own LED plant light.

She’s using a combination of red and blue LEDs that produce the ratio of light frequencies that plants thrive on, and has been experimenting with how bright to make them and how long to run them. This combination of factors determines how much light the plants get every day, called the Daily Light Integral, or DLI, and has a huge effect on how well the plants grow.

Her latest prototype uses nine red and two blue 3 Watt LEDs which run for about twenty hours a day. These lights shine onto the growing area, a bucket filled with nutrient solution. [Margaret] has done an excellent job of outlining why and how she made the choices she did and providing lots of links to more information for the home grower. It’s a great place to start for anyone looking to get something growing indoors in the depths of winter.

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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Cellular Automata Explorer

Well all know cellular automata from Conway’s Game of Life which simulates cellular evolution using rules based on the state of all eight adjacent cells. [Gavin] has been having fun playing with elementary cellular automata in his spare time. Unlike Conway’s Game, elementary automata uses just the left and right neighbors of a cell to determine the next cell ahead in the row. Despite this comparative simplicity, some really complex patterns emerge, including a Turing-complete one.

[Gavin] started off doing the calculations by hand for fun. He made some nice worksheets for this. As we can easily imagine, doing the calculations by hand got boring fast. It wasn’t long before his thoughts turned to automating his cellular automata. So, he put together an automatic cellular automator. (We admit, we are having a bit of fun with this.)

This could have been a quick software project but half the fun is seeing the simulations on a purpose-built ecosystem. The files to build the device are hosted on Thingiverse. Like other cellular automata projects, it uses LED matrices to display the data. An Arduino acts as the brain and some really cool retro switches from the world’s most ridiculously organized electronics collection finish the look of the project.

To use, enter the starting condition with the switches at the bottom. The code on the Arduino then computes and displays the pattern on the matrix. Pretty cool and way faster than doing it by hand.

Testing the Speed-of-Light Conspiracy

There are a number of ways to measure the speed of light. If you’ve got an oscilloscope and a few spare parts, you can build your own apparatus for just a few bucks. Don’t believe the “lies” that “they” tell you: measure it yourself!

OK, we’re pretty sure that conspiracy theories weren’t the motivation that got [Michael Gallant] to build his own speed-of-light measurement rig, but the result is a great writeup, and a project that includes one of our favorite circuits, the avalanche transistor pulse generator.

setupThe apparatus starts off with a very quickly pulsed IR LED, a lens, and a beam-splitter. One half of the beam takes a shortcut, and the other bounces off a mirror that is farther away. A simple op-amp circuit amplifies the resulting pulses after they are detected by a photodiode. The delay is measured on an oscilloscope, and the path difference measured with a tape measure.

If you happen to have a photomultiplier tube in your junk box, you can do away with the amplifier stage. Or if you have some really fast logic circuits, here’s another project that might interest you. But if you just want the most direct measurement we can think of that’s astoundingly accurate for something lashed up on breadboards, you can’t beat [Michael]’s lash-up.

Oh and PS: He got 299,000 (+/- 5,000) km/sec.