big LED flashlight

Own The Night With This Ludicrously Bright DIY Flashlight

If you’re a flashlight person, you know that there’s little you would do to get the brightest, most powerful, most ridiculous flashlight possible. You might even decide to build yourself a ludicrously powerful flashlight, like [Maciej Nowak] did.

If you choose the DIY route, be warned that it’s probably not going to be a simple process, at least if you follow [Maciej]’s lead. His flashlight is machined out of aluminum rounds, all turned down on the lathe to form the head of the flashlight. The head is made from three parts, each of which acts as a heat sink for the five 20-Watt CREE XHP70 LED modules. The LEDs are mounted with care to thermal considerations, and wired in series to DC-DC converter that provides the necessary 30 V using a battery pack made from four 21700 Li-ion cells. The electronics, which also includes a BMS for charging the battery and a MOSFET switching module, form a tidy package that fits into the aluminum handle.

The video below shows that the flashlight is remarkably bright, with a nice, even field with no hotspots. Given the 45-minute useful life and the three-hour recharge time, it might have been nice to make it so anywhere from one to five of the LEDs could be turned on at once. Some interesting effects might be had from switching the LEDs on sequentially, too.

Given the proclivities of our community, it’s no surprise that this is hardly the first powerful flashlight we’ve seen. This one broke the 100-Watt barrier with a single COB LED, while this ammo-can version sports an even higher light output. Neither of them looks much like a traditional flashlight, though, which is where [Maciej]’s build has the edge.

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PCB fluorescent 7-segment display

Unique Seven-Segment Display Relies On FR-4 Fluorescence

It’s interesting what you see when you train a black light on everyday objects. We strongly suggest not doing this in a hotel room, but if you shine UV light on, say, a printed circuit board, you might see what [Sam Ettinger] did, which led him to build these cool low-profile seven-segment fluorescent PCB displays.

UV light causing FR4 to fluoresceAs it turns out, at least some FR-4 PCBs fluoresce under UV light, giving off a ghostly blue-green glow. Seeing the possibilities, [Sam] designed a PCB with cutouts in the copper and solder mask in the shape of a traditional seven-segment display. The backside of the PCB has pads for UV LEDs and current-limiting resistors, which shine through the board and induce the segments to glow. Through-slots between the segments keep light from one segment from bleeding over into the next; while [Sam] left the slots unfilled, they could easily be filled with solder. The fluorescent property of FR-4, and therefore the brightness and tint of the segments, seems to vary by board thickness and PCB manufacturer, but it looks like most PCBs will show pretty good results.

We’d say the obvious first improvement might be to cover the back of the display with black epoxy, to keep stray light down, and to improve contrast. But they look pretty great just as they are. We can also see how displays with other shapes, like icons and simple symbols. Or maybe even alphanumeric characters — say, haven’t we seen something like that before?

FFT display on 16x16 RGB LED grid

Art Project Fast And Fouriously Transforms Audio Into Eye Candy

Fast Fourier Transforms. Spectrum Analyzers. Waterfall displays. Not long ago, such terms were reserved for high end test gear. But oh, how things have changed! It’s no surprise to many Hackaday readers that modern microcontrollers have transformed the scene as they become more powerful and as a result are endowed with more and more powerful software libraries. [mircemk] has used such a library along with other open source software combined with mostly off the shelf hardware to create what he calls the DIY FFT Spectrum Analyzer. Rather than being a piece of test gear, this artful project aims to please the eye.

The overall build is relatively simple. Audio is acquired via a line-in jack or a microphone, and then piped into an ESP32. The ESP32 runs the audio through the FFT routine, sampling, slicing, and dicing the audio into 16 individual bands. The visual output is displayed on a 16 x 16 WS2812 Led Matrix. [mircemk] wrote several routines for displaying the incoming audio, with a waterfall, a graph, and other visualizations that are quit aesthetically pleasing. Some of them are downright mesmerizing! You can see the results in the video below the break.

Of course the build doesn’t stop with slapping some hardware and a few passive components together. To really be finished, it needs to be encased in something worth displaying. [mircemk] does not disappoint, as a beautiful 3D-printed enclosure wraps it all up nicely.

We think that the final product is great, and it reminds us of some of the very things that inspired us early on in our hacking careers. We would love to see this project integrated with an Interactive Musical Art Installation of any kind, the more esoteric the better. Perhaps a 555 timer synth could fit the bill? Be sure to share your own hacks with us via the Tip Line!

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Exploring An Aftermarket LED Headlight Retrofit Kit

There’s plenty of debate about drop-in LED headlight bulbs, especially when they’re used with older reflector housings that were designed for halogen bulbs. Whether or not you personally feel the ultra-bright lights are a nuisance, or even dangerous, one thing we can all agree on is that they’re clearly the result of some impressive engineering.

Which is why we were fascinated to see the teardown [TechChick] did on a “Ultra 2 LED” retrofit from GTR Lighting. Apparently one of the diodes was failing, and as part of the warranty replacement process, she was informed she had to make it completely inoperable. Sounds like a teardown dream come true. If a manufacturer ever told us we needed to take something apart with extreme prejudice and provide photographic evidence that the deed was done, we’d be all too happy to oblige.

The driver itself ended up being completely filled with potting compound, so she doesn’t spend much time there. Some will no doubt be annoyed that [TechChick] didn’t break out the small pointy implements and dig all that compound out, but we all pretty much know what to expect when it comes to driving LEDs. The real interesting bit is the bulb itself.

As is common with these high-output automotive LEDs, the Ultra 2 is actively cooled with a small fan that’s actually enclosed within the heatsink. With the fan and the two-piece heatsink removed, she’s able to access the LED module itself. Here, two PCBs are sandwiched back to back with a hollow copper chamber that leads out of the rear of the module. When [TechChick] cut into the copper she said she heard a hiss, and assumed it was some kind of liquid cooling device. Specifically we think it’s a vapor chamber that’s being used to pull heat away from the diodes and into the heatsink at the rear of the module, which speaks to the advanced technology that makes these bulbs possible.

While laser headlights are arguably the future of automotive lighting, it’s going to be quite some time before they trickle down to those of us that don’t own supercars. Until then, when used responsibly, these LED retrofits can inject a bit of cutting-edge tech into your old beater without breaking the bank.

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Salvaging Working LEDs From “Dead” Light Bulbs

Sure the box said they would last for years or even decades, but anyone who’s picked up some bargain LED bulbs knows the reality is a bit more complicated. Sometimes a few LEDs in the array pop, reducing the overall light output. More commonly, the power supply starts to fail and the bulb begins to flicker or hum. In either event, you end up pulling the bulb and replacing it.

But [Bifferos] thinks we can do a bit better than that. Rather than just chalking it up to poor QA and tossing the bulb, why not do a little exploratory surgery to identify salvageable LEDs in an otherwise “dead” bulb? After pulling apart a couple of burned out bulbs (name brand and otherwise), he was able to pull out an impressive number of handy LED panels that could be easily repurposed. Naturally, with a little more coaxing, the individual SMD LEDs could be liberated and pushed into service as well.

Separate PCBs with banks of LEDs are ideal for reuse.

As you might expect, there are far too many different LED bulbs out there to create a comprehensive teardown guide, but [Bifferos] does provide some tricks to help get the bulb open without hurting yourself or destroying the thing in the process. Once inside, the design of the bulb will dictate what happens next. Bulbs with multiple arrays of LEDs on their own PCBs can be easily broken down, but if there’s just the single board, you may want to pull the LEDs off individually. To that end, the write-up demonstrates efficient methods of stripping the LEDs using either hot air or a pair of soldering irons.

We’ve talked previously about the rather underwhelming performance of modern LED bulbs compared to the manufacturer’s lofty claims. We’d rather see these bulbs designed well enough that they actually live up to their full potential, but the ability to salvage useful components from the failed luminaries at least softens the blow of having to toss them early. Though that’s not the only reason you should disassemble your LED bulbs before you put them in the trash.

Interactive LED Shoes That Anyone Can Build!

Normally when we see blinky projects these days, it’s using addressable LED strips with WS2812Bs, or similar alternatives. However, old-school blobby round LEDs are still on the market, and can still be put to great use. These DIY LED shoes from [TechnoChic] are an excellent example of just that.

The shoes use big 10mm LEDs that have color-changing smarts baked in. Simply power them up and they’ll fade between a series of colors. They’re run from a coin cell sewn on to the side of each shoe, with the LEDs jammed into the rear of the sole. A conductive product called Maker Tape is then used to create a circuit for the LEDs and the coin cell, along with a pressure switch inside each shoe. When the wearer puts weight on their heel, the switch conducts, lighting up the LEDs as the wearer takes each step.

This isn’t the first time we’ve seen a pair of shoes bedazzled with LEDs, but it’s arguably the easiest version of the concept to grace these pages. This is a quick way to create interactive flashing LED gadgets, and a great way for beginner makers to jazz up their projects.

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Automated musical instrument with LED array

ESP32 Is The Brains Behind This Art Installation

The ESP32 has enabled an uncountable number of small electronics projects and even some commercial products, thanks to its small size, low price point, and wireless capabilities. Plenty of remote sensors, lighting setups, and even home automation projects now run on this small faithful chip. But being relegated to an electronics enclosure controlling a small electrical setup isn’t all that these tiny chips can do as [Eirik Brandal] shows us with this unique piece of audio and visual art.

The project is essentially a small, automated synthesizer that has a series of arrays programmed into it that correspond to various musical scales. Any of these can be selected for the instrument to play through. The notes of the scale are shuffled through with some random variations, allowing for a completely automated musical instrument. The musical generation is entirely analog as well, created by some oscillators, amplifiers, and other filtering and effects. The ESP32 also controls a lighting sculpture that illuminates a series of LEDs as the music plays.

The art installation itself creates quite haunting, mesmerizing tunes that are illustrated in the video linked after the break. While it’s not quite to the realm of artificial intelligence since it uses pre-programmed patterns with some randomness mixed in, it does give us hints of some other projects that have used AI in order to compose new music.

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