Build Your Own RGB Fill Light For Photography

April 19, 2024 by Lewin Day 12 Comments

Photography is all about light, and capturing it for posterity. As any experienced photographer will tell you, getting the right lighting is key to getting a good shot. To help in that regard, you might like to have a fill light. If you follow [tobychui]’s example, you can build your own!

The build relies on addressable WS2812B LEDs as the core of the design. While they’re not necessarily the fanciest LEDs for balanced light output, they are RGB LEDs, so they can put out a ton of different colors for different stylistic effects. The LEDs are under the command of a Wemos D1, which provides a WiFI connection for wireless control of the light.

[tobychui] did a nice job of building a PCB for the project, including heatsinking to keep the array of 49 LEDs nice and cool. The whole assembly is all put together inside a 3D printed housing to keep it neat and tidy. Control is either via onboard buttons or over the WiFi connection.

Files are on GitHub if you’re seeking inspiration or want to duplicate the build for yourself. We’ve seen some other similar builds before, too. Meanwhile, if you’re cooking up your own rad photography hacks, don’t hesitate to let us know!

Trick Your (1970) Pickup Truck

March 26, 2024 by Al Williams 23 Comments

[Dave] wanted an old pickup, and he found a GMC Sierra Grande truck vintage 1970. While it had an unusual amount of options, there weren’t that many high-tech options over 50 years ago. The five-year-long restoration work was impressive, as you can see in the video below, but we were really interested in the electronics part. As [Dave] mentions, the truck was made when the Saturn V was taking people to the moon, but after his modifications, the truck has a lot more computing power than the famous rocket.

He was concerned that the taillights were not up to modern standards and that it would be too easy for someone using their cell phone to plow into the rear of the truck. So he broke out an ESP32 and some LEDs and made an attractive brake light that would have been a high-tech marvel in 1970.

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Celebrating Pi Day With A Ghostly Calculator

March 14, 2024 by Tom Nardi No comments

For the last few years, [Cristiano Monteiro] has marked March 14th by building a device to calculate Pi. This year, he’s combined an RP2040 development board and a beam-splitting prism to create an otherworldly numerical display inspired by the classic Pepper’s Ghost illusion.

The build is straightforward thanks to the Cookie board from Melopero Electronics, which pairs the RP2040 with a 5×5 matrix of addressable RGB LEDs. Since [Cristiano] only needed 4×5 LED “pixels” to display the digits 0 through 9, this left him with an unused vertical column on the right side of the array. Looking to add a visually interesting progress indicator for when the RP2040 is really wracking its silicon brain for the next digit of Pi, he used it to show a red Larson scanner in honor of Battlestar Galactica.

With the MicroPython code written to calculate Pi and display each digit on the array, all it took to complete the illusion was the addition of a glass prism, held directly over the LED array thanks to a 3D-printed mounting plate. When the observer looks through the prism, they’ll see the reflection of the display seemingly floating in mid-air, superimposed over whatever’s behind the glass. It’s a bit like how the Heads Up Display (HUD) works on a fighter jet (or sufficiently fancy car).

Compared to his 2023 entry, which used common seven-segment LED displays to show off its fresh-baked digits of Pi, we think this new build definitely pulls ahead in terms of visual flair. However, if we had to pick just one of [Cristiano]’s devices to grace our desk, it would still have to be his portable GPS time server.

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LED Choker Is A Diamond In The Junk Pile

March 12, 2024 by Kristina Panos 9 Comments

Isn’t it great when you find a use for something that didn’t work out for the project it was supposed to? That’s the story behind the LED strips in this lovely blinkenlights choker by [Ted].

The choker itself is a 15 mm wide leather strap with holes punched in it. According to [Ted], the hole punching sounds like the absolute worst and hardest part to do, because the spacing of the holes must be greater than that of the LEDs to account for flex in the strap. [Ted] tested several distances and found that there is little margin for error.

Controlling those blinkenlights is a Seeed Xiao S3, which fits nicely behind the neck in what looks like a heat shrink tube cocoon. [Ted] chose this because there was one lying around, and it happens to be a good fit with its LiPo charge controller.

The choker runs on four 300 mAh LiPo batteries, which makes for more bulk than [Ted] would like, but again, sometimes it’s about what you have lying around. Even so, the batteries last around two hours.

Sometimes it’s about more than just blinkenlights. Here’s an LED necklace that reports on local air quality.

The Photodiode You Never Knew You Had

February 28, 2024 by Jenny List 34 Comments

Optoelectronics hold a range of possibilities for the hardware experimenter — indeed who among us hasn’t added LEDs aplenty to our work? What many of us may be unaware of though is that an LED is also a photodiode, and can even be persuaded to generate usable quantities of power. [Voltative] takes a look at this phenomenon with a series of experiments.

Lighting up an LED from a set of other LEDs is pretty cool, as is powering a calculator, or even the calculator powering itself from its on-board LED. But what caught our eye was using two LEDs as a data link, with both of them acting as transmitter and receiver (something on searching we find we’ve seen before). The possibilities there become interesting indeed.

Given that we are now surrounded by LEDs, from OLED screens to LED lighting, we can’t help wondering what the photodiode performance of some other types of part might be. Would the large area of a lighting LED give a better result for example, or would the phosphorescent coating of a white LED make it useless. We feel there’s more scope for experimentation here.

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Tetris Goes Round And Round

February 24, 2024 by Al Williams 4 Comments

You’ve probably played some version of Tetris, but [the Center for Creative Learning] has a different take on it. Their latest version features a cylindrical playing field. While it wouldn’t be simple to wire up all those LEDs, it is a little easier, thanks to LED strips. You can find the code for the game on GitHub.

In all, there are 5 LED strips for a display and 13 strips for the playing area, although you can adjust this as long as there are at least 10 rows. The exact number of LEDs will depend on the diameter of the PVC pipe you build it on.

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LED Matrix Earrings Show Off SMD Skills

February 21, 2024 by Dan Maloney 12 Comments

We’ll be honest with you: we’re not sure if the use of “LED stud” in [mitxela]’s new project refers to the incomprehensibly tiny LED matrix earrings he made, or to himself for attempting the build. We’re leaning toward the latter, but both seem equally likely.

This build is sort of a mash-up of two recent [mitxela] projects — his LED industrial piercing, which contributes the concept of light-up jewelry in general as well as the power supply and enclosure, and his tiny volumetric persistence-of-vision display, which inspired the (greatly downsized) LED matrix. The matrix is the star of the show, coming in at only 9 mm in diameter and adorned with 0201 LEDs, 52 in total on a 1 mm pitch. Rather than incur the budget-busting expense of a high-density PCB with many layers and lots of blind vias, [mitexla] came up with a clever workaround: two separate boards, one for the LEDs and one for everything else. The boards were soldered together first and then populated with the LEDs (via a pick-and-place machine, mercifully) and the CH32V003 microcontroller before being wired to the power source and set in the stud.

Even though most of us will probably never attempt a build on this scale, there are still quite a few clever hacks on display here. Our favorite is the micro-soldering iron [mitxela] whipped up to repair one LED that went missing from the array. He simply wrapped a length of 21-gauge solid copper wire around his iron’s tip and shaped a tiny chisel point into it with a file. We’ll be keeping that one in mind for the future.

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