Hexagonal Lamp Is A Stylish Application Of Plywood

February 21, 2019 by Lewin Day 10 Comments

Lamps are useful things, and can be a great way to add style and lighting options to a room. Where overhead lights have to provide enough illumination for all manner of tasks, a subtle table lamp can add a nice moody glow to a room when it’s time to kick back and relax. Oftentimes, a stylish lamp can be let down by having a run of the mill plastic switch hanging off the power lead, but it doesn’t always have to be the case. [Emiel] designed this hexagonal lamp with a hidden switch, which works remarkably well.

[Emiel] starts by laying out hexagonal paper templates on plywood and perspex sheet. The plywood is cut on the bandsaw, while the interior cuts on the perspex are made on a scroll saw to avoid unsightly cut entry lines. The outer half of the lamp slides up and down on a pair of steel rods. Springs hold the outer half up, and it can be pressed down to activate a switch inside to turn the lamp on and off.

The build has a clean and attractive aesthetic, with the LEDs hidden inside, glowing through the perspex slices built into the body. It looks like something you’d find in the rooms at the Tranquility Base Hotel & Casino. If regular lamps aren’t enough for you, however, you could always consider building something interactive. Video after the break.

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Inefficient NeoPixel Control Solved With Hardware Hackery

February 18, 2019 by Eric Evenchick 40 Comments

Everyone loves NeoPixels. Individually addressable RGB LEDs at a low price. Just attach an Arduino, load the demo code, and enjoy your blinking lights.

But it turns out that demo code isn’t very efficient. [Ben Heck] practically did a spit take when he discovered that the ESP32 sample code for NeoPixels used a uint32 to store each bit of data. This meant 96 bytes of RAM were required for each LED. With 4k of RAM, you can control 42 LEDs. That’s the same amount of RAM that the Apollo Guidance Computer needed to get to the moon!

His adventure is based on the thought that you should be able to generate these signals with hardware SPI. First, he takes a look at Adafruit’s DMA-Driven NeoPixel example. While this is far more efficient than the ESP32 demo code, it still requires 3 SPI bits per bit of NeoPixel data. [Ben] eventually provides us with an efficient solution for SPI contro using a couple of 7400 series chips:

[Ben]’s solution uses some external hardware to reduce software requirements. The 74HC123 dual multi-vibrator is used to generate the two pulse lengths needed for the NeoPixels. The timing for each multi-vibrator is set by an external resistor and capacitor, which are chosen to meet the NeoPixel timing specifications.

The 74HC123s are clocked by the SPI clock signal, and the SPI data is fed into an AND gate with the long pulse. (In NeoPixel terms, a long pulse is a logical 1.) When the SPI data is 1, the long pulse is passed through to the NeoPixels. Otherwise, only the short pulse is passed through.

This solution only requires a 74HC123, an AND gate, and an OR gate. The total cost is well under a dollar. Anyone looking to drive NeoPixels with a resource-constrained microcontroller might want to give this design a try. It also serves as a reminder that some problems are better solved in hardware instead of software.

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Infinity Icosahedron Is Difficult To Contemplate Even Looking Right At It

February 17, 2019 by Lewin Day 13 Comments

Cubes and pyramids are wonderful primitive three-dimensional objects, but everyone knows that the real mystical power is in icosahedrons. Yes, the twenty-sided polyhedron does more than just ruin your saving throws in tabletop RPGs – it can also glow and look shiny in your loungeroom at home.

[janth]’s build relies on semitransparent acrylic mirrors for the infinity effect, lasercut into triangles to form the faces of the icosahedron. The frame is built out of 3D printed rails which slot on to the acrylic mirrors, and also hold the LED strips. [janth] chose high-density strips with 144 LEDs per meter for a more consistent effect, and added frosted acrylic diffusers to all the strips for a clean look with less hotspots from the individual LEDs.

An ESP32 runs the show, and the whole assembly is epoxied together for strength. The final effect is very future disco, and it’s probably against medical advice to stare at it for more than 5 minutes at a time.

The infinity effect is a popular one, and we’ve seen a beautiful cube build by [Heliox] in recent times. Of course, if you do manage to build an actual portal through time and space, and not just a lamp that looks like one, be sure to send us a tip. Video after the break.

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Is That A Word Clock In Your Pocket?

February 15, 2019 by Tom Nardi 10 Comments

Word clocks are one of those projects that everyone seems to love. Even if you aren’t into the tech behind how they work, they have a certain appealing aesthetic. Plus you can read the time without worrying about those pesky numbers, to say nothing of those weird little hands that spin around in a circle. This is the 21st century, who has time for that?

Now, thanks to [Gordon Williams], these decidedly modern timepieces just got a lot more accessible. His word clock is not only small enough to fit in the palm of your hand, but it’s the easiest-to-build one we’ve ever seen. If you were ever curious about these gadgets but didn’t want to put in the the time and effort required to build a full scale version, this diminutive take on the idea might be just what Father Time ordered.

The trick is to attach the microcontroller directly to the backside of an 8 x 8 LED matrix. As demonstrated by [Gordon], the Bluetooth-enabled Espruino MDBT42Q fits neatly between the rows of pins, which need only a gentlest of persuasions to get lined up and soldered into place. Since the time can be set remotely over Bluetooth, there’s not even so much as an additional button required. While driving the LEDs directly off of the digital pins of a microcontroller is never recommended, the specifics of this application (only a few of the LEDs on at a time, and not for very long) means he can get away with it.

Of course, that just gets you an array of square LEDs you blink. It wouldn’t be much of a word clock without, you know, words. To that end, [Gordon] has provided an overlay which you can print on a standard inkjet printer. While it’s not a perfect effect as the light still comes through the ink, it works well enough to get the point across. One could even argue that the white letters on the gray background helps with visibility compared to just the letters alone lighting up.

If you’re not in the market for a dollhouse-sized word clock, fear not. We’ve got no shortage of adult sized versions of these popular timepieces for your viewing pleasure.

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COB LED Teardown

February 15, 2019 by Al Williams 15 Comments

[Big Clive] picked up some chip-on-board (COB) LEDs meant for hydroponics that were very unusual and set out to examine them on video. Despite damaging the board almost right away, he managed to do some testing on these arrays and you can see the results in the video below. He also compares it to older LED modules.

The 144 LEDs produce a lot of light. In addition to powering the device up, he also looks at the construction of the LEDs under a magnification, comparing the older style that used tiny bond wires to make connections versus the new version soldered on the board directly.

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The Empire Strikes Back With The ESP8266

February 13, 2019 by Tom Nardi 1 Comment

Like many of us, [Matthew Wentworth] is always looking for a reason to build something. So when he found a 3D model of the “DF.9” laser turret from The Empire Strikes Back intended for Star Wars board games on Thingiverse, he decided it was a perfect ~~excuse~~ opportunity to not only try his hand at remixing an existing 3D design, but adding electronics to it to create something interactive.

As the model was originally intended for a board game, it was obviously quite small. So the first order of business was scaling everything up to twice the original dimensions. As [Matthew] notes, the fact that it still looks so good when expanded by such a large degree is a credit to how detailed the original model is. Once blown up to more useful proportions, he modified the head of the turret as well as the barrel to accept the electronics he planned on grafting into the model.

He created a mount for a standard nine gram servo inside the head of the turret which allows it to rotate, and the barrel got an LED stuck in the end. Both of which are controlled with a NodeMCU ESP8266 development board, allowing [Matthew] to control the direction and intensity of the pew-pew over WiFi. He mentions that in the future he would like to add sound effects that are synchronized to the turret rotation and LED blinking.

For the software side of the project, he used Blynk to quickly build a smartphone interface for the turret. This is the first time he had used Blynk, and reports that outside of a little trial and error, it was some of the easiest code he’s ever written for the Arduino. This is a sentiment we’ve been seeing a lot of recently towards Blynk, and it’s interesting to see how often it shows up in ESP8266 projects now.

Looking ahead [Matthew] says he wants to paint and detail the turret, as the bright orange color scheme probably wouldn’t do terribly well on Hoth. If he can manage the time, he’d also like to add it to the long list of OpenCV-powered turrets that hackers love harassing their friends and family with.

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Freeform Wire Frame Tulip Blooms To The Touch

February 12, 2019 by Roger Cheng 5 Comments

Holidays are always good for setting a deadline for finishing fun projects, and every Valentine’s Day we see projects delivering special one-of-a-kind gifts. Why buy a perishable bulk-grown biological commodity shipped with a large carbon footprint when we can build something special of our own? [Jiří Praus] certainly seemed to think so, his wife will receive a circuit sculpture tulip that blooms when she touches it.

This project drew from [Jiří]’s experience with aesthetic LED projects. His Arduino-powered snowflake, with LEDs mounted on a custom PCB, is a product available on Tindie. For our recent circuit sculpture contest, his entry is a wire frame variant on his snowflake. This tulip has 7 Adafruit NeoPixel in the center and 30 white SMD LEDs in the petals, which look great. But with the addition of mechanical articulation, this project has raised the bar for all that follow.

We hope [Jiří] will add more details for this project to his Hackaday.io profile. In the meantime, look over his recent Tweets for more details on how this mechanical tulip works. We could see pictures and short videos of details like the wire-and-tube mechanism that allowed all the petals to be actuated by a single servo, and the components that are tidily packaged inside that wooden base.

Need more digital expressions of love? We have no shortage of hearts. Animated LED hearts, illuminated acrylic hearts, and talking hearts. We’re a little short on flower projects, but we do have X-ray of a rose among others to accompany [Jiří]’s tulip.

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