Technoblogy presents an adjustable load that provides a constant-current load for testing power supplies and batteries. It allows setting the load current to up to 1.05A, using a potentiometer, and displays the current on a three-digit LED display controlled by an ATtiny84.

As well as testing power supplies, the adjustable load can be used for testing rechargeable NiMH and Li-ion batteries under different load conditions. It measures the current over time, and displays the battery’s capacity in mAh or Ah. This is useful for comparing different makes of battery, or for deciding whether a battery has reached the end of its life.

The constant-current circuit is based on an LT3080 regulator. This uses a current reference of 10µA, rather than a voltage reference like regulators such as the LM317, and will operate down to 1.5V and a few mA.

The current is sensed by a 1Ω resistor, and this is fed to the sense input of the regulator, via a 100kΩ potentiometer and 5.1kΩ resistor. Since the current through the potentiometer and resistor is 10µA, at the potentiometer’s maximum setting the voltage across them will be 1.05V, so the output of the regulator will be maintained at 1.05V across the 1Ω resistor, producing a constant current of 1.05A.

The current is displayed on a three-digit 7-segment display. I used a 0.28″ three-digit common anode seven-segment LED display.

See this project in the post here.

Fusion of Helios is a 140 megapixel image of the sun created by Andrew McCarthy and Jason Guenzel. Here’s more from @AJamesMcCarthy on Twitter:

A blend of science and art, this photo combined over 90,000 images meticulously layered and processed to reveal our star in a way you’ve never seen before.

see more more on Twitter purchase from Cosmic Background

Every Tuesday is Art Tuesday here at Adafruit! Today we celebrate artists and makers from around the world who are designing innovative and creative works using technology, science, electronics and more. You can start your own career as an artist today with Adafruit’s conductive paints, art-related electronics kits, LEDs, wearables, 3D printers and more! Make your most imaginative designs come to life with our helpful tutorials from the Adafruit Learning System. And don’t forget to check in every Art Tuesday for more artistic inspiration here on the Adafruit Blog!

Charlie Schick was inspired by this clever little Valentine’s Day card from the delightfully creative Charlyn (left), made with a wee Trinket M0 (a fave), NeoPixels (blikenlights!), laser cut parts, a 3D printed case, and rechargeable battery.

I took a side step in my head and got a brainwave to do something similar on my 3D printer. And I could mount it all into an Ikea frame I had left over from my lithophane project.

Then I started thinking of my heartbeat, and that I always wanted to do something around it. Y’see, my wife has the same number of letters in her first name to match the PQRST of an EKG trace – hence there’s a connection between my EKG and her – my heart, indeed, beats for her.

I was experimenting and refactoring the (CircuitPython) code, such that when I was ready, I was able to just copy and paste it, and then tweak it, for the QtPy I ended up using (actually, a QtPy Haxpress I had made a long time ago).

See the details on this project in the blog post here.

Matt Millman blogs about two designs which provide additional PCIe slots in modern computers.

The first, above, is a small form factor OCuLink/U.2 To PCIe X4 adapter.

Some time ago I designed an “as small as possible” adapter to make use of spare OCuLink/U.2 ports that are often seen on PC motherboards these days. There are of course ready made products which more-or-less do the same thing, but they were all oversized, awkward and difficult to incorporate into an small form factor (SFF) build.

OCuLink is an extension for the “cable version of PCI Express”, acting as a competitor to versions 3 and 4 of the Thunderbolt interface. See this on GitHub and the blog post.

Second is a PCIe Bifurcation Riser,

I designed a couple of PCIe Bifurcation risers to solve some difficult build problems I was faced with, namely fitting a second PCIe card into a case which was only designed for one.

See this project on GitHub and the blog post.

via NPR

No one…has, to my knowledge, ever met Tiptree, ever seen him, ever talked with him on the phone. No one knows where he lives, what he looks like, what he does for a living…. He volunteers no information about his personal life, and politely refuses to answer questions about it…. Most SF people…are wild to know who Tiptree “really” is. — Gardner Dozois, 1976

From the New York Times

In an introduction to “Warm Worlds and Otherwise,” a 1975 collection of short stories by the elusive and enigmatic James Tiptree Jr., his editor and fellow author Robert Silverberg attempted to sketch a portrait of a cult figure who had never been seen in public, and whose only tangible connection to the known universe was a steady stream of letters originating from a post office box in McLean, Va. Though some fans believed that the mysterious Tiptree was actually J.D. Salinger or Henry Kissinger, Silverberg speculated that the writer was probably employed as a federal bureaucrat, around 50 or 55 years old, and enjoyed the outdoors…

As science fiction readers would learn just a few months later, Tiptree was closer in age to 61 but was an avid traveler and gun enthusiast who had worked for the United States government. Also, James Tiptree Jr. was a woman named Alice Sheldon.

Tiptree’s writing won Sheldon the epistolary friendships of science fiction masters like Philip K. Dick, Ursula K. Le Guin and Harlan Ellison, as well as awards she could not easily claim (at least not in person), but her gamesmanship was growing exponentially more complicated. In 1976, she let it slip in a letter from Tiptree to a fanzine editor named Jeffrey D. Smith that Tiptree’s mother, already known by devoted readers to be an African explorer, had died. After consulting a recent obituary in The Chicago Tribune, Smith wrote back to Tiptree, “Word is spreading very fast that your true name is Alice Sheldon.” A few days later, the author dutifully replied: “Yeah. Alice Sheldon. Five ft 8, 61 yrs, remains of a good-looking girl vaguely visible, grins a lot in a depressed way, very active in spurts.”

From NPR

In 1921 in the Belgian Congo, a six-year-old girl from Chicago with a pith helmet on her blond curls walks at the head of a line of heavily laden native porters. Her mother walks next to her, holding a rifle and her daughter’s hand.

In 1929, the girl huddles under quilts in a cabin in the Great North Woods, reading Weird Tales. The candle by her bed flickers as an alien gently removes a young human’s brassiere.

On Christmas Eve 1934, a nineteen-year-old in a white beaded evening gown makes her debut. At the party she meets a handsome, dark-haired boy in a tie and tails. She makes a joke; he laughs, and makes another. Five days later they elope and marry.

In 1942, a divorcee wearing three-inch heels and a fox fur jacket goes down to a Chicago recruiting station and enlists in the Army.

Sometime in the near future, a woman and a man meet an extraterrestrial exploring party. The man tries to protect the woman. The woman says she doesn’t believe in women’s chances on Earth, and asks the aliens to take her away.

In 1970, a man who does not exist sits down at a typewriter. He writes, “At last I have what every child wants, a real secret life. Not an official secret, not a Q-clearance polygraph-enforced bite-the-capsule-when-they-get-you secret, nobody else’s damn secret but MINE.”

Her legacy has led to the James Tiptree, Jr. Literary Award

In February of 1991 at WisCon (the world’s only feminist-oriented science fiction convention), award-winning SF author Pat Murphy announced the creation of the James Tiptree, Jr. Literary Award, an annual literary prize for science fiction or fantasy that expands or explores our understanding of gender. Pat created the award in collaboration with author Karen Joy Fowler. The aim of the award is not to look for work that falls into some narrow definition of political correctness, but rather to seek out work that is thought-provoking, imaginative, and perhaps even infuriating. The Tiptree Award is intended to reward those writers and other creative artists who are bold enough to contemplate shifts and changes in gender roles, a fundamental aspect of any society.

Read more

James Tiptree, Jr.: The Double Life of Alice B. Sheldon

Great video from Insider showing a professional restoration of a 1940s neon sign. There are few things that evoke nostalgia for early 20th century Americana quite as quickly and overwhelmingly as a neon sign.

Howie Cohen, who owns Just Neon Sign Company, shows us how it’s done:

The pieces he works on often go into private collections, never to be seen again. Howie walks us through the steps for restoring a $30,000 Hudson neon sign from the 1940s.

North American Signs posted a neat, brief history of the golden age of neon lights back in 2021 if you’re interested in learning more.

Some fascinating inventions from a ancient Turkish polymath. Reminscant of Da Vinci; some of Ismail al-Jazari‘s diagrams are practical some are a bit fantastical. From Open Culture.

A resident of Diyar-Bakir, in modern-day Turkey, he was employed as a court engineer, and indeed, proved to be the finest engineer for which a Mesopotamian ruler of that era could hope. He worked out a variety of functional camshafts, crankshafts, pumps, fountains, and clocks, not to mention his more ambitious designs, including a host of humanoid automata meant to handle tasks like serving beverages and even playing music.

Read more! and See many more of them illustrated at Flashbak

#circuitpythonparsec
How to use DotStar RGB LEDs in CircuitPython

Who better to explain how synthesizers work but Thomas Dolby, with help from some muppets? Here’s more from the Jim Henson Company:

When Farkas buys a robot to help him get rid of the musicians of Faffner Hall on Make a New Sound Day, the gang borrows some parts from the robot to construct a synthesizer so they can make all kinds of new sounds. Fughetta doesn’t understand how a synthesizer works so the Wild Impressario turns to his best source, Thomas Dolby, to explain it to her.

See and hear more!

The Microsoft MakeCode team has announced the preview release of the MakeCode Arcade extension for Visual Studio Code.

You can now import your games into the Visual Studio Code environment, or even start a MakeCode Arcade game from scratch in VS Code. Why would you want to do this? You might if you:

• Are comfortable writing your MakeCode Arcade games in Typescript/JavaScript.
• Would like access to full language support and intellisense.
• Have a complex game that you might want to split up into multiple code files.
• Want to build skills using a professional development tool.
• Are itching for richer editing tools like syntax highlighting, bracket-matching, auto-indentation, keyboard shortcut mappings and refactoring tools.
• Want to use Live Share or other VS Code extensions.

To get started, see this brief setup page.

Adam Ragusea, host of The Pub, interviews NPR’s senior director of audio engineering Shawn Fox to ask the question NPR listeners want to know – How did you come up with what’s been described as NPR’s “secret sauce”? for Current:

Current: What is ingredient number one of the secret sauce? Is it the NPR studio microphone?

Fox: The NPR sound has so many tentacles. If we’re just focusing on the studio side, which was actually the easiest thing, it all starts with the microphone. We use a simple Neumann U87 microphone as the house-standard microphone at all of our facilities. They’re expensive, but that’s what we’ve used for years.

In the new building, we knew we had the old microphones — and microphones don’t die unless somebody really works hard at it — and we had more facilities, so we bought a few more. But it really comes down to the U87 with the bass rolled off.

Current: The bass rolled off? Could you explain what that means?

Read more

AI-powered chatbots are part of the future of computing, and it’s only a matter of time before you’ll see them appear on every internet-connected gadget. If you thought you were safe from this by sticking to an ancient MS-DOS PC though, think again: Yeo Kheng Meng has recently written a ChatGPT client that runs on DOS.

Yeo Kheng Meng tested the client on a real 1984 vintage IBM 5155 Portable PC. This semi-portable PC/XT model sports a 4.77 MHz 8088 CPU, 640 kB of RAM and a CGA video card with a built-in monochrome monitor. An NE2000 ISA network card, running in 8-bit mode, enables the Portable to connect to the internet.

See the video below and more details on Hackaday.

(Video) While doing a teardown of a toy cactus that mimics people by recording & replaying the last few seconds of audio, we were reminded of ISD audio chips.

These record-and-playback chips have been around for decades and are a favorite with makers and engineers who want to quickly add audio prompt playback without big processing capability. These chips don’t require battery backup or a flash memory chip, they keep the audio clips stored internally in a compressed format.

Originally these were popularized in use cases like “digital greeting cards” that you could record a message onto. Despite being quite old, they’re still used a lot and are very simple and often available in large packages, so for many projects they’re still the easiest way to do add simple sound effects or audio messages. Digi-Key has a wide range of ISD audio chips available for purchase, let’s look at the large range and pick a good one to start with.

See the chosen chip on Digi-Key

Todd at Project Farm was curious to know how a cheap knockoff of a $500 Stihl chainsaw would perform against the real deal.

As you might imagine, the real Stihl outperformed both of the cheap saws Todd tested. But what was surprising is that the $100 Topteng saw (on Amazon on time of testing) performed amazingly well and looks like a decent purchase if you’re in the market for a chainsaw, but don’t want/need a top-of-line tool.

Carnivorous plants are definitely the bad boys of botany (in a good way).

Volume 190 Issue 1 of Plant Physiology, published back in September 2022, devotes a significant amount of time to carnivorous plants and detailing their many systems.

Here’s a succinct tidbit from the article that describes the main difference between animal and carnivorous plant digestive systems:

Although trap leaves share many functions with animal digestive tracts, there are striking differences in their spatial arrangements (Figure 1). Most vertebrate digestive tracts are divided into functionally specialized organs such as the mouth, stomach, and intestines, where food is digested and absorbed in distinct compartments (Hedrich, 2015). In carnivorous plants, however, the prey does not travel through a digestive tract but instead remains in the same organ where it was captured for subsequent digestion and absorption

Chris of Clickspring continues his video series on setting up a home machine shop. In this video, he looks at the very intimidating subject of choosing a metal lathe. He starts off by applying three basic criteria: cost, space, and what are you planning to make.

Answering these questions will instantly help narrow down your field of choices. He cautions you to remember to include all of the tooling and accessories you’ll need to operate your lathe and to consider an ample amount of space to move freely around your lathe for cleaning and maintenance.

From there he runs through what specifications to pay attention to and what features to look for. He also discusses the possible weaknesses of cheaper import lathes and what can be done to overcome them.

And through it all, you get to hear the awesome way he pronounces “lathe” in his Aussie accent.

I first saw the 1956 sci-fi masterpiece, Forbidden Planet, on a late night “Creature Feature” when I was maybe 13 or 14 years old. With it’s eerie “electronic tonalities” score, the strange, craggy planet of Altair IV, the endlessly thrumming underground machinery a lost advanced civilization below it, and a monster from the ID, I’m sure I had the strangest nightmares that night.

As an older teen and adult, watching it countless times since, I marvel at how well much of it holds up. My god, 1956! And I’ve come to understand the innovative brilliance of the Cedric Gibbons and Arthur Lonergan sets, the Joshua Meador animations, the pioneering electronic music–so incredible ahead of its time–by Bebe and Louis Barron, and the MGM art department’s now-iconic design of Robby the Robot.

Here are a few snippets of recovered “lost” footage from the film and some deleted scenes.

That is one way to improve on the often maligned MVMT watch! The maker on W&M Levsha crafts this itty bitty chess set. Through some meticulous machining, laser printing and more they craft every piece on the board. Love these mellow process videos!

Today I will show you the process of remaking a wristwatch. I will make an unusual dial with chess pieces for them. I hope you enjoy the result!

See more!

Adafruit 3D Printed Chess Set

Mystery Box: Remote Chess Board Puzzle Lock

ADAFRUIT WEEKLY EDITORIAL ROUND-UP

We’ve got so much happening here at Adafruit that it’s not always easy to keep up! Don’t fret, we’ve got you covered. Each week we’ll be posting a handy round-up of what we’ve been up to, ranging from learn guides to blog articles, videos, and more.

BLOG

100 CircuitPython Community Libraries!

The CircuitPython community reached a big milestone together! There are now 100 libraries in the CircuitPython Community Bundle! CircuitPython libraries are separate files designed to work with CircuitPython code.

Check out the full post here!

More BLOG:

Keeping with tradition, we covered quite a bit this past week. Here’s a kinda short nearing medium length list of highlights:

• This week in Women’s History Month
• World Pupperty Day
• World Water Day 2023
• Anne Barela on Hackster Café
• The Monarch could be the next big thing in Braille
• Vintage Synth Service Note
• New Yorkers friendlier than expected as robots take out the trash
• Rose B. Simpson’s Road Less Traveled
• Cheers to 37,000 members in the Adafruit Discord community!

LEARN

MIDI Controlled Robot Lyre with CircuitPython

What they don’t tell you about starting a band is that the hardest part is organizing the people. So, why not skip that step and build a bunch of MIDI controlled robots to play music with?

In this project, you’ll mount servo motors over the strings of a lyre. The servos will pluck those strings when they receive MIDI NoteOn messages via a Feather RP2040 running CircuitPython. You can control the lyre with an eternal MIDI controller or by sending MIDI out from your favorite DAW program.

See the full guide here!

More LEARN:

• Adafruit Metro M7 1011 with AirLift

Browse all that’s new in the Adafruit Learning System here!

New nEw NEWs From Adafruit is an email newsletter sent out once a week to subscribers only. It features new products, special offers, exciting original content, and more. Sign-up NOW for the Adafruit weekly Newsletter here: https://www.adafruit.com/newsletter