Building A Neatly Framed Word Clock

Reading analog clocks is a pretty straightforward skill to learn. However, if you’ve already learned to read and don’t want to pick up the extra skill, a word clock is a perfect solution for telling time. [povey_tech] found some nice examples in the wild but didn’t appreciate the price, so he set about building his own.

The build is based around an ESP32 microcontroller. While many projects in this vein would use the onboard wireless connectivity to query network time servers, in this case, the board relies on the user manually setting the time and a DS1307 real-time-clock module to keep a steady tick. Also onboard is a VEML7700 ambient light sensor, which the microcontroller uses to control the brightness of the WS2812 LEDs inside the board.

The words themselves are laser cut out of acrylic panels, with everything set inside a tidy oak picture frame. A layer of anti-reflective glass in front helps cut down on glare, while [povey_tech] was so kind as to implement two LEDs per letter to allow for lovely color gradients to be displayed. Configuring the clock is easy thanks to a webpage hosted on the ESP32 that allows for control of dimming modes, colors, and setting the time. Home Assistant integration is something planned for the future.

We’ve seen many great word clocks over the years. Perhaps the biggest leap forward in this world was the development of the addressable LED strip which made constructing these clocks much easier.

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Driving WS2812Bs With Pure Logic

The WS2812B has become one of the most popular addressable LEDs out there. They’re easy to drive from just about any microcontroller you can think of. But what if you don’t have a microcontroller at all? [Povilas Dumcius] decided to try and drive the LEDs with raw logic only.

The project consists of a small board full of old-school ICs that can be used to drive WS2812Bs in a simplistic manner. A 74HC14 Schmitt trigger oscillator provides the necessary beat for this tune, generating an 800 kHz clock to keep everything in time and provide the longer pulse trains that represent logic one to a WS2812B. A phase-shifted AND gate generates the shorter pulses necessary to indicate logic zero. Meanwhile, a binary counter cycles through 24 bits (8 per R, G, and B) to handle color. Pressing each one of the three push-buttons allows each color channel to be activated or deactivated as desired. It can make the strip red, green, or blue, or combine the channels if you press multiple buttons at once. That’s all the control you get—it would take a bit more logic to enable variable levels of each channel. Certainly within the realms of possibility, though.

We’ve featured some other nifty tricks for driving WS2812Bs in unconventional ways, like using DMA hardware or even I2S audio outputs. If you’ve got your own tricks, don’t hesitate to notify the tipsline.

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Building An Interactive Climbing Wall

Climbing is a cool sport. With that said, like everything, it’s even better if you integrate lots of glowing colorful LEDs. To that end, [Superbender] worked up this fun climbing wall that features interactive lighting built right in.

Structurally, there’s nothing too wild going on here. It’s a wood-framed climbing structure that stands 10 meters long and 2.5 meters high, and can be covered in lots of climbing holds. It’s the electronic side of things where it gets fun. An Arduino Due is installed to run the show, hooked up with a small TFT display and some buttons for control. It’s then hooked up to control a whole bunch of LEDs and some buttons which are scattered all across the wall. It’s also paired with an Arduino Nano which runs sound feedback, and a 433 MHz remote for controlling the system at a distance.

[Superbender] uses the lighting for fun interactive games. One example is called Hot Lava, where after each climbing pass, more holds are forbidden until you can’t make the run anymore. Chase the Blues is another fun game, where you have to climb towards a given hold, at which point it moves and you have to scamper to the next one.

We’ve featured similar projects before from other inventive climbers.

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Modded Lightbox Makes For Attractive LED Matrix Display

If you’ve been to a wedding or a downtown coffee shop in the last 10 years, you’ve probably seen those little lightboxes that are so popular these days. They consist of letters placed on a plastic frame in front of a dim white light, and they became twee about five minutes after your hipster friend first got one. However, they can also make a neat basis for an LED display, as [Folkert van Heusden] demonstrates. 

The build is straightforward enough, using daisy chains of 32×8 LED matrix modules, two each for the three rows of the lightbox. This provides for a 24 character textual display, or a total display resolution of 64 x 24 pixels. An ESP8266 is used to command the matrixes, which are run by MAX7219 display controllers. Thanks to the microcontroller’s onboard wireless hardware, the display can be addressed in a number of ways, such as using the LedFX DDP protocol or [Folkert’s] Pixel Yeeter python library. Files are on GitHub for the curious.

Quite a few of these exist out in the wild — [Folkert] has built a variety of modded lightboxes over the years with varying internals. The benefit of the lightbox is that it effectively acts as a handy housing for LED matrixes and supporting electronics, while also providing a neat diffuser effect. The lightboxes are also readily wall mountable and generally look more like an intentional piece of signage than most things we might homebrew in the lab.

We’ve featured similar-looking builds before, like this public transit display that was hacked for custom use. If you’re building your own public information boards or other nifty LED displays, don’t hesitate to notify the tipsline!

A Candle-Powered Light

For a little over two thousand years, the primary light sources after the sun had set were oil lamps and candles. This was well before the age of fossil fuels, so these oil lamps were often fueled with a labor-intensive agricultural product like olive oil. Candles were similarly difficult to make, made from tallow, beeswax, or even butter. Labor and materials costs aside, though, there’s a surprising amount of energy in these fuels and [Maciej Nowak Projects] has a generator that help these ancient light sources generate some electricity on the side.

The generator is based around a piece of technology called a thermoelectric generator (TEG), which produces a voltage potential when placed in a temperature gradient. These aren’t new technologies, but their typically low efficiencies limit where they can be effectively used. In this case, however, [Maciej Nowak] has gone to great effort to boost this efficiency as high as possible by using a huge radiator on the cool side of the TEG and another one on the hot side, which in this case is heated by a small tea candle. The electricity produced is sent to a tiny DC converter which regulates the voltage to 3.3V, which then powers two custom-built pedestal lamps on either side of the TEG, each with a high-efficiency LED mounted to a custom-made circuit board.

Although this is certainly not the first time a TEG has been set up to run a small lighting system, we do appreciate this one for its polish, design, and high efficiency. It would make a fitting addition to anyone’s emergency power outage kit as it really increases the amount of available light produced from any given candle. When taken to the extreme, though, thermoelectric generators can be made to produce a surprising amount of energy, provided they are placed in the right environment.

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Real LED TVs Are Finally Becoming A Thing

Once upon a time, the cathode ray tube was pretty much the only type of display you’d find in a consumer television. As the analog broadcast world shifted to digital, we saw the rise of plasma displays and LCDs, which offered greater resolution and much slimmer packaging. Then there was the so-called LED TV, confusingly named—for it was merely an LCD display with an LED backlight. The LEDs were merely lamps, with the liquid crystal doing all the work of displaying an image.

Today, however, we are seeing the rise of true LED displays. Sadly, decades of confusing marketing messages have polluted the terminology, making it a confusing space for the modern television enthusiast. Today, we’ll explore how these displays work and disambiguate what they’re being called in the marketplace.

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LED Interior Lighting Could Compromise Human Visual Performance

LED lighting is now commonplace across homes, businesses, and industrial settings. It uses little energy and provides a great deal of light. However, a new study suggests it may come with a trade-off. New research suggests human vision may not perform at its peak under this particular form of illumination.

The study ran with a small number of subjects (n=22) aged between 23 to 65 years. They were tested prior to the study for normal visual function and good health. Participants worked exclusively under LED lighting, with a select group then later also given supplemental incandescent light (with all its attendant extra wavelengths) in their working area—which appears to have been a typical workshop environment.

Incandescent bulbs have a much broader spectrum of output than even the best LEDs. Credit: Research paper

Notably, once incandescent lighting was introduced, those experimental subjects showed significant increases in visual performance using ChromaTest color contrast testing. This was noted across both tritan (blue) and protan (red) axes of the test, which involves picking out characters against a noisy background. Interestingly, the positive effect of the incandescent lighting did not immediately diminish when those individuals returned to using purely LED lighting once again. At tests 4 and 6 weeks after the incandescent lighting was removed, the individuals continued to score higher on the color contrast tests. Similar long-lasting effects have been noted in other studies involving supplementing LED lights with infrared wavelengths, however the boost has only lasted for around 5 days.

The exact mechanism at play here is unknown. The study authors speculate as to a range of complex physical and biological mechanisms that could be at play, but more research will be needed to tease out exactly what’s going on. In any case, it suggests there may be a very real positive effect on vision from the wider range of wavelengths provided by good old incandescent bulbs. As an aside, if you’ve figured out how to get 40/40 vision with a few cheap WS2812Bs, don’t hesitate to notify the tip line.

Thanks to [Keith Olson] for the tip!