Surface Mount Breathing Light PCB, using LM358 op-amp

Surface-Mount Light Breathes Life Into Your Project

November 11, 2022 by Dave Walker 13 Comments

If you’ve ever seen those gadgets with the “breathing light” LEDs on them and wondered how to do it, then [DIY GUY Chris] can show you how to design your own surface-mount version, using only analogue electronics.

Simulation trace showing the LED breathing light circuit operating. Traces for voltage and current are shown over a few seconds — The LED current tracks up and down in an approximately triangular-wave pattern

The circuit itself is built around a slow triangular-wave oscillator, that ramps the current up and down in the LEDs to make it look as if the lights are breathing in and out. The overall effect is rather pleasing, and the oscillation speed can be adjusted using the on-board potentiometer.

This project is actually an update to a previous version that used through-hole components (also shown in the video below), and goes to show that revisiting completed projects can give them a new lease of life. It also shows how easy it has become to design and order custom circuit boards these days. It’s not so long ago that a project like this would have been either made on stripboard or etched from copper-plated FR4 in a bubbling tank of acid!

If you have revisited an old project that you’re proud of and would like to show others, why not drop us a message on our tips line?

We have covered some other options for breathing LEDs in the past, such as this digital logic version, and this Arduino library that has a host of other effects to choose from, too. Continue reading “Surface-Mount Light Breathes Life Into Your Project” →

A diagram showing an LED on the left, a lever-style plumbing valve in the center, and an Arduino Uno on the right.

Plumbing Valves As Heavy Duty Analog Inputs

October 24, 2022 by Navarre Bartz 36 Comments

Input devices that can handle rough and tumble environments aren’t nearly as varied as their more fragile siblings. [Alastair Aitchison] has devised a brilliant way of detecting inputs from plumbing valves that opens up another option. (YouTube) [via Arduino Blog]

While [Aitchison] could’ve run the plumbing valves with water inside and detected flow, he decided the more elegant solution would be to use photosensors and an LED to simplify the system. This avoids the added cost of a pump and flow sensors as well as the questionable proposition of mixing electronics and water. By analyzing the change in light intensity as the valve closes or opens, you can take input for a range of values or set a threshold for an on/off condition.

[Aitchison] designed these for an escape room, but we can see them being great for museums, amusement parks, or even for (train) simulators. He says one of the main reasons he picked plumbing valves was for their aesthetics. Industrial switches and arcade buttons have their place, but certainly aren’t the best fit in some situations, especially if you’re going for a period feel. Plus, since the sensor itself doesn’t have any moving parts, these analog inputs will be easy to repair should anything happen to the valve itself.

If you’re looking for more unusual inputs, check out the winners of our Odd Inputs and Peculiar Peripherals contest or this typewriter that runs Linux.

Continue reading “Plumbing Valves As Heavy Duty Analog Inputs” →

Neodriver Ornament Brightens Up Christmas

October 21, 2022 by Lewin Day 11 Comments

Stores will sell you all kinds of gaudy holiday ornaments, but there’s nothing like the style and class achieved by building your own. [w3arycod3r] did just that, whipping up the fun and festive Neodriver Ornament.

It’s a battery-powered build, and runs off an rechargeable 18650 cell which provides several days of operation at a low duty cycle. An ATtiny85 is charged with sending out commands to various NeoPixel devices, from rings to rectangular arrays. [w3arycod3r] then designed various PCBs that could carry the hardware and battery in a well-balanced package that would hang nicely when suspended from a ribbon on a Christmas tree.

As is always the fun part with addressable LEDs, [w3arycod3r] whipped up some fun animations to suit. The 5×5 rectangular arrays of NeoPixels are able to deliver scrolling text, while another animation blips out the RNA sequence of everyone’s least favorite coronavirus, SARS-CoV-2. Getting everything to fit into a ATtiny85’s 8 KB of code space and 512 byte EEPROM was a challenge, but slimming down the Adafruit NeoPixel library and using direct AVR register manipulation in place of regular Arduino functions helped.

Overall, it’s a fun holiday build that looks great on the tree. Alternatively, consider making yourself some rheoscopic ornaments this holiday season. And, if you’ve whipped up your own fun holiday build, throw it on the tipsline!

Two shots of a Thriller jacket with LED strips being worn by Louise Katzovitz, one from the front and the other from the back.

Thrills With An LED “Thriller” Jacket

October 11, 2022 by Abe Connelly 19 Comments

[Louise Katzovitz] has created a light-up jacket in the style of the jacket worn by Michael Jackson in the 1983 music video for “Thriller”. [Louise Katzovitz]’s Thriller jacket is the perfect example of combining sewing hacks and electronic hacks to make an awesome, wearable jacket.

A bomber jacket was used as the base form to layer on the sequins and LED strips. Instead of bands of metal studs, [Louise] used WS2812B 60 pixels/m LED strips. 3D-printed transparent PLA “gems” were placed on top of the LEDs to mimic the form of the metal studs in the original jacket and provide diffusion for the underlying LEDs.

Each LED strip was laid out on a piece of vinyl strip. Then, a top layer of vinyl was cut to allow each of the LEDs to poke through, with the 3D printed gems super-glued on top. The assembled LED bands are attached to the jacket by Velcro with the wiring fed behind the lining material, which can be removed easily via small hooks. The whole thing is driven by an Arduino Nano and a 5 V power bank.

With the details and process worked out, [Louise] even made a tiny version of the jacket for her dog. We’ve featured LED wearables and fashion before and [Louise]’s jacket is a great addition. These projects are perfect for anyone who wants to wow their friends this upcoming Halloween season. Video after the break!

Continue reading “Thrills With An LED “Thriller” Jacket” →

laser cut acrylic coaster with rgb leds inside

Your Mug Will Like This Glowy Coaster

September 28, 2022 by Abe Connelly 2 Comments

[Charlyn] wanted to highlight their friends beautiful mug collection, so the Glowy Coaster was born.

The coaster is made up of six layers of laser cut acrylic. The top and bottom layer are cut out of clear acrylic, providing a flat surface for the coaster. A top pattern layer made of pearl acrylic has a thin piece of vellum put underneath it to provide diffusion for the LED strip sandwiched inside. The middle layers are made of peach acrylic and have their centers hollowed out to provide room for the electronics inside. The top pearl acrylic layer gives the coaster, as [Charlyn] writes, a “subtle touch of elegance”. The coaster itself is screwed together by an M3 screw at each point of the hexagon that feed through to heat-set inserts.

The electronics consist of a short NeoPixel strip, cut to include 12 LEDs pointed in towards the center of the coaster. The LEDs are driven by a Trinket M0 microcontroller with a LiPo “backpack” to provide power, attachment points for the exposed power switch and recharging capability to the 110 mAh 3.7 V battery. The code is a slightly modified NeoPixel “rainbow” wheel loop (source available as a gist). The design files are available through Thingiverse.

Creations like these highlight how much care and work goes into a project with minimal beauty, where decisions, like the opacity and thickness of the acrylic or countersinking the M3 screws, can have huge consequences for the overall aesthetic. [Charlyn] has an attention to detail that brings an extra touch of professionalism and polish to the project.

Coasters are a favorite for laser cutting and we’ve covered many different types, including
coaster bots, coaster engravers and even a color changing, drink sensing coasters.

Continue reading “Your Mug Will Like This Glowy Coaster” →

As Europe Goes To LEDs, Scientists Worry

September 19, 2022 by Al Williams 271 Comments

There was a time when street lighting means someone had to go light the lamps. Electricity changed that, but street and outdoor lighting has been quietly going through a new revolution: LEDs. The problem, though, is that LEDs provide what scientists call “broad white” light and there are concerns about the impact the unnatural lighting will have on ecosystems, including people and animals.

Of course, the first step in worrying about something is to measure it. You would think that satellites would have a bird’s-eye view of the nighttime lighting landscape, and, of course, they do. But most of the imagery isn’t suitable for looking at the spectrum of wavelength data scientists need to quantify what they call ALAN — Artificial Light at Night.

The ISS imaging is, however, sufficient. Using special data techniques, they were able to track the adoption of LEDs over sodium lights and other technologies between 2012-2013 and 2014-2020 across Europe. For example, in the title image, you can see Belgium with an orange tint indicating low-pressure sodium lights. The Netherlands, France, and the UK have a more yellow hue, indicating high-pressure sodium lamps. Germany is more of a blue color due to fluorescent and mercury vapor bulbs.

Continue reading “As Europe Goes To LEDs, Scientists Worry” →

Circuit-less PCB Featured As Faceplate For A Digital Clock

August 17, 2022 by Dan Maloney 9 Comments

If there’s no circuitry on a printed circuit board, does it cease being a “PCB” and perhaps instead become just a “PB”?

Call them what you will, the fact that PCBs have become so cheap and easy to design and fabricate lends them to more creative uses than just acting as the wiring for a project. In this case, [Jeremy Cook] put one to work as the faceplate for his “742 Clock,” a name that plays on the fact that his seven-segment display is 42 mm tall, plus it’s “24/7” backward.

In addition to the actual circuit board that holds the Wemos ESP32 module and the LEDs, a circuit-less board was designed with gaps in the solder mask to act as light pipes. Sandwiched between the boards is a 3D printed mask, to control the light and direct it only through the light pipes. [Jeremy] went through a couple of iterations of diffuser and mask designs, finally coming up with a combination that works well and looks good. He mentions a possible redesign of the faceplate board to include a copper backplane for better opacity, which we think is a good idea. We’d also like to see how different substrates work; would boards of different thickness or using FR-4 with different glass transition temperatures work better? Check out the video below and see what you think.

We’re seeing more and more PCBs turn up as structural elements, from enclosures to control panels and even tools, and we approve of this trend. But what we really approve of is what [Jeremy] did here by making this clock just a dumb display that gets network time over NTP. Would that all three digital clocks in our kitchen did the same thing — maybe then they wouldn’t each be an infuriating minute out of sync with the others.

Continue reading “Circuit-less PCB Featured As Faceplate For A Digital Clock” →