Give Your Solar Garden Lights A Color Changing LED Upgrade

White LEDs were the technological breakthrough that changed the world of lighting, now they are everywhere. There’s no better sign of their cost-effective ubiquity than the dollar store solar garden light: a complete unit integrating a white LED with its solar cell and battery storage. Not content with boring white lights on the ground, [Emily] decided to switch up their colors with a mix of single-color LEDs and dynamic color-changing LEDs, then hung them up high as colorful solar ornaments.

The heart of these solar devices is a YX8018 chip (or one of its competitors.) While the sun is shining, solar power is directed to charge up the battery. Once the solar cell stops producing power, presumably because the sun has gone down, the chip starts acting as a boost converter (“Joule thief”) pushing a single cell battery voltage up high enough to drive its white LED. Changing that LED over to a single color LED is pretty straightforward, but a color changing LED adds a bit of challenge. The boost converter deliver power in pulses that are too fast for human eyes to pick up but the time between power pulses is long enough to cause a color-changing circuit to reset itself and never get beyond its boot-up color.

The hack to keep a color-changing LED’s cycle going is to add a capacitor to retain some charge between pulses, and a diode to prevent that charge from draining back into the rest of the circuit. A ping-pong ball serves as light diffuser, and the whole thing is hung up using a 3D-printed sheath which adds its own splash of color.

Solar garden lights are great basis for a cheap and easy introduction to electronics hacking. We’ve seen them turn into LED throwies, into a usable flashlight, or even to power an ATTiny microcontroller.

Continue reading “Give Your Solar Garden Lights A Color Changing LED Upgrade”

Random Word Pairings Mark The Time On This Unusual Clock

Gosh, the fun we had when digital calculators became affordable enough that mere grade school students could bring one to class. The discovery that the numbers could be construed as the letters of various dirty words when viewed upside down was the source of endless mirth. They were simpler times.

This four-letter-word “clock” aims to recreate that whimsical time a bit, except with full control over the seven-segment displays and no need to look at it upside down. This descends from a word clock [WhiskeyTangoHotel] made previously and relies on a library of over 1000 four-letter words that can be reasonably displayed using seven-segment displays, most of them SFW but some mildly not. A PICAXE is used to select two of the four-letter words to display every second or so, making this a clock only by the loosest of definitions. Word selection is pseudorandom, seeded by noise from a floating ADC pin, but some of the word pairings in the video below seem to belie a non-random sense of humor. As is, there are over a million pairings possible; it might be fun to add in the full set of two- and three-letter words as well and see what sort of merriment ensues.

While we like the Back to the Future vibe here, we’ve seen some other really nice word clocks lately. There was the one that used PCBs as the mask for the characters, and then a rear-projection word clock that really looks great.

Continue reading “Random Word Pairings Mark The Time On This Unusual Clock”

Replicating 1970s LED Displays

In 1971, Texas Instruments released something no one else had ever seen before. The TIL305 was an alphanumeric display, powered by LEDs. Sure, the technology of the early 70s meant the LEDs weren’t very bright, and the displays were expensive, but if you want a display that’s simply classic, and relatively low-power, you won’t be able to do better than a vintage alphanumeric LED display.

As you would expect, new old stock TIL305s are still pricey, and now everybody has access to cheap PCB manufacturing capabilities and really small LEDs. The DIYTIL305 is an attempt to replicate the vintage stuff, and it looks great.

The vintage, TI-made TIL305 is a printed circuit board that clips into a DIP-14 socket. The LED array is 5×7 pixels, with an extra dot for a decimal point, set on a 0.05″ grid, and a translucent red diffuser. A PCB is easy, and with 0201 LEDs you can get the LED pitch you need. Turning a PCB into a DIP-14 only requires a few machine pin headers, and for the diffuser, this project is using laser cut cast acrylic. It’s simple if you have a pick and place machine or a steady hand, and assembly is a snap.

The final DIYTIL305 boards are being tested right now, but so far the results are great. With the right code on a microcontroller, these displays will blink through the digits 0 through 9, and the alphabet is just a little more code. Since this project is using 0201 LEDs, it also means green, white, blue, orange, and yellow displays are possible, something no one could have dreamed of in 1971.

An Even Smaller World’s Smallest LED Blinky

Everything can be done with a 555. It’s a universal law, as all readers know. And a flashing light, you might think, will have been done before many times. But nobody has ever created a 555 flashing light as small as thie one created by [TWires], who has taken a TI LMC555 chip-scale packaged 555 and dead-bugged a working flasher on its surface using 01005 discrete components. There is a video showing it in operation that we’ve placed below the break, and it’s tiny. We probably all consider ourselves to be quite good at soldering, but this piece of work is in another class entirely.

The project was inspired by [Mike Harrison]’s previous holder of the smallest blinky prize, which used a PIC microcontroller atop a tiny surface mount supercapacitor. It uses the same capacitor for power, but we’d say it’s taken the blinky to new levels of tininess. Does this mean a new arms race is upon us in the world of tiny blinkies? We hope so, and though it’s difficult to imagine they can get much smaller we can’t wait to see what people come up with. If there’s one thing about our community it’s that saying something can’t be done is unwise: one of you will find a way if it is at all possible. Even Microchip’s MIC1555 might be a bit big though, so something inventive is called for.

For a fascinating run-down of the state of the 555 art, read this article from our own [Ted Yapo].

Continue reading “An Even Smaller World’s Smallest LED Blinky”

A Word Clock, The Hard Way

We’ve all seen word clocks, and they’re great, but there are only so many ways to show the time in words. This word clock with 114 servos is the hard way to do it.

We’re not sure what [Moritz v. Sivers] was aiming for with this projection clock, but he certainly got it right. The basic idea is to project the characters needed to compose the time messages onto a translucent PVC screen, which could certainly have been accomplished with just a simple character mask and some LEDs. But for extra effect, [Moritz] mounted each character to a letterbox mounted over a Neopixel. The letterboxes are attached to a rack and pinion driven by a micro servo. The closer they get to the screen, the sharper the focus and the smaller the size of the character. Add in a little color changing and the time appears to float out from a jumbled, unfocused background. It’s quite eye-catching, and worth the 200+ hours of printing time it took to make all the parts. Complete build instructions are available, and a demo video is after the break.

We like pretty much any word clock – big, small, or even widescreen. This one really pushes all our buttons, though.

Continue reading “A Word Clock, The Hard Way”

Components Cut in Half Reveal their Inner Beauty

We rarely take a moment to consider the beauty of the components we use in electronic designs. Too often they are simply commodities, bought in bulk on reels or in bags, stashed in a drawer until they’re needed, and then unceremoniously soldered to a board. Granted, little scraps of black plastic with silver leads don’t exactly deserve paeans sung to their great beauty – at least not until you cut them in half to reveal the beauty within.

We’ve seen a little of what [Tube Time] has accomplished here; recall this lapped-down surface-mount inductor that [electronupdate] did a while back. The current work is more extensive and probably somewhat easier to accomplish because [TubeTime] focused mainly on larger through-hole components such as resistors and capacitors. It’s not clear how the sections were created, but it is clear that extreme care was taken to lap down the components with enough precision that the inner structures are clearly visible, and indeed, carefully enough that some, most notably the LED, still actually work. For our money, though, the best looking cross-sections are the capacitors, especially the electrolytic, for which [Tube Time] thoughtfully provides both radial and axial sections. The little inductor is pretty cool too. Some of the component diagrams are annotated, too, which makes for fascinating reading.

Honestly, we could look at stuff like this all day.

Thanks to [Stuart Rogers] for the tip.

Ammo Can Holds A 14,000 Lumen LED Flashlight

For most people, a flashlight is just something you keep in a drawer in the kitchen in case the power goes out. There’s even a good chance your “flashlight” is just an application on your phone at this point. But as we’ve seen many times before from mechanical keyboards to Power Wheels, hardcore niche communities can develop around the most innocuous pieces of hardware; and the lowly flashlight is no different.

Case in point, this 14,000 lumen LED flashlight built by [Bryson Hicks]. Designed around a 100 watt module from Stratus LED, the flashlight uses a number of 3D printed components to make itself at home in a suitably hardcore enclosure: a metal ammo can. With the addition of some modular electronics and a rather slick little control panel, his light is ready to deliver an unreasonable level of brightness anywhere he wishes.

The Stratus LED module includes its own driver, and just needs to be hooked up to a suitably beefy power source to do its thing. [Bryson] went with a 4500 mAh LiPo battery that he says gets him about a one hour runtime at full brightness. For somewhat less intense operation, he’s added a potentiometer which interfaces with the module’s driver board to control the LED output. Considering how fast the light sucks down the juice, adding a small LCD battery charge indicator to the top of the device seems like it was a prudent decision.

To prevent you from cooking anyone’s eyes at close range, the light requires you to first “arm” it by flipping the military style protected switch. Once the switch is in the on position, an illuminated push button is used to actually turn the LED module on and off. You can also snap the toggle switch back into the closed and covered position if you needed to kill the light in a hurry.

This isn’t the first preposterously bright LED flashlight we’ve seen around these parts. There’s something of an arms-race between hackers and makers to develop increasingly bright lights they can carry around, on the off chance they need to illuminate an entire neighborhood.