Day: March 19, 2025

World’s Smallest Blinky, Now Even Smaller

March 19, 2025 by 21 Comments

Here at Hackaday, it’s a pretty safe bet that putting “World’s smallest” in the title of an article will instantly attract comments claiming that someone else built a far smaller version of the same thing. But that’s OK, because if there’s something smaller than this nearly microscopic LED blinky build, we definitely want to know about it.

The reason behind [Mike Roller]’s build is simple: he wanted to build something smaller than the previous smallest blinky. The 3.2-mm x 2.5-mm footprint of that effort is a tough act to follow, but technology has advanced somewhat in the last seven years, and [Mike] took advantage of that by basing his design on an ATtiny20 microcontroller in a WLCSP package and an 0201 LED, along with a current-limiting resistor and a decoupling capacitor. Powering the project is a 220-μF tantalum capacitor, which at a relatively whopping 3.2 mm x 1.6 mm determines the size of the PCB, which [Mike] insisted on using.

Assembling the project was challenging, to say the least. [Mike] originally tried a laboratory hot plate to reflow the board, but when the magnetic stirrer played havoc with the parts, he switched to a hot-air rework station with a very low airflow. Programming the microcontroller almost seemed like it was more of a challenge; when the pogo pins he was planning to use proved too large for the job he tacked leads made from 38-gauge magnet wire to the board with the aid of a micro hot air tool.

After building version one, [Mike] realized that even smaller components were available, so there’s now a 2.4 mm x 1.5 mm version using an 01005 LED. We suspect there’ll be a version 3.0 soon, though — he mentions that the new TI ultra-small microcontrollers weren’t available yet when he pulled this off, and no doubt he’ll want to take a stab at this again.

Pick Up A Pebble Again

March 19, 2025 by 23 Comments

A decade ago, smartwatches were an unexplored avenue full of exotic promise. There were bleeding-edge and eye-wateringly expensive platforms from the likes of Samsung or Apple, but for the more experimental among technophiles there was the Pebble. Based on a microcontroller and with a relatively low-resolution display, it was the subject of a successful crowdfunding campaign and became quite the thing to have. Now long gone, it has survived in open-source form, and now if you’re a Pebble die-hard you can even buy a new Pebble. We’re not sure about their choice of name though, we think calling something the “Core 2 Duo” might attract the attention of Intel’s lawyers.

The idea is broadly the same as the original, and remains compatible with software from back in the day. New are some extra sensors, longer battery life, and an nRF52840 BLE microcontroller running the show. It certainly captures the original well, however we’re left wondering whether a 2013 experience still cuts it in 2025 at that price. We suspect in that vein it would be the ideal compliment to your game controller when playing Grand Theft Auto V, another evergreen 2013 hit.

We look forward to seeing where this goes, and we reported on the OS becoming open source earlier this year. Perhaps someone might produce a piece of open source hardware to do the same job?

Closeup of the original Manchester Baby CRT screen

Modern Computing’s Roots Or The Manchester Baby

March 19, 2025 by 13 Comments

In the heart of Manchester, UK, a groundbreaking event took place in 1948: the first modern computer, known as the Manchester Baby, ran its very first program. The Baby’s ability to execute stored programs, developed with guidance from John von Neumann’s theory, marks it as a pioneer in the digital age. This fascinating chapter in computing history not only reshapes our understanding of technology’s roots but also highlights the incredible minds behind it. The original article, including a video transcript, sits here at [TheChipletter]’s.

So, what made this hack so special? The Manchester Baby, though a relatively simple prototype, was the first fully electronic computer to successfully run a program from memory. Built by a team with little formal experience in computing, the Baby featured a unique cathode-ray tube (CRT) as its memory store – a bold step towards modern computing. It didn’t just run numbers; it laid the foundation for all future machines that would use memory to store both data and instructions. Running a test to find the highest factor of a number, the Baby performed 3.5 million operations over 52 minutes. Impressive, by that time.

Despite criticisms that it was just a toy computer, the Baby’s significance shines through. It was more than just a prototype; it was proof of concept for the von Neumann architecture, showing us that computers could be more than complex calculators. While debates continue about whether it or the ENIAC should be considered the first true stored-program computer, the Baby’s role in the evolution of computing can’t be overlooked.

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This M5Stack Game Is Surprisingly Addictive

March 19, 2025 by 3 Comments

For those of us lucky enough to have been at Hackaday Europe in Berlin, there was a feast of hacks at our disposal. Among them was [Vladimir Divic]’s gradients game, software for an M5Stack module which was definitely a lot of fun to play. The idea of the game is simple enough, a procedurally generated contour map is displayed on the screen, and the player must navigate a red ball around and collect as many green ones as possible. It’s navigated using the M5Stack’s accelerometer, which is what makes for the engaging gameplay. In particular it takes a moment to discover that the ball can be given momentum, making it something more than a simple case of ball-rolling.

Underneath the hood it’s an Arduino .ino  file for the M5Stack’s ESP32, and thus shouldn’t present a particular challenge to most readers. Meanwhile the M5Stack with its versatile range of peripherals has made it onto these pages several times over the years, not least as a LoRA gateway.

From The Ashes: Coal Ash May Offer Rich Source Of Rare Earth Elements

March 19, 2025 by 33 Comments

For most of history, the world got along fine without the rare earth elements. We knew they existed, we knew they weren’t really all that rare, and we really didn’t have much use for them — until we discovered just how useful they are and made ourselves absolutely dependent on them, to the point where not having them would literally grind the world to a halt.

This dependency has spurred a search for caches of rare earth elements in the strangest of places, from muddy sediments on the sea floor to asteroids. But there’s one potential source that’s much closer to home: coal ash waste. According to a study from the University of Texas Austin, the 5 gigatonnes of coal ash produced in the United States between 1950 and 2021 might contain as much as $8.4 billion worth of REEYSc — that’s the 16 lanthanide rare earth elements plus yttrium and scandium, transition metals that aren’t strictly rare earths but are geologically associated with them and useful in many of the same ways. Continue reading “From The Ashes: Coal Ash May Offer Rich Source Of Rare Earth Elements” →

Reviving A Maplin 4600 DIY Synthesizer From The 1970s

March 19, 2025 by 15 Comments

A piece of musical history is the Maplin 4600, a DIY electronic music synthesizer from the 1970s. The design was published in an Australian electronics magazine and sold as a DIY kit, and [LOOK MUM NO COMPUTER] got his hands on an original Maplin 4600 that he refurbishes and puts through its paces.

Inserting conductive pegs is how the operator connects different inputs and outputs.

The Maplin 4600 is a (mostly) analog device with a slightly intimidating-looking layout. It features multiple oscillators, mixers, envelope generators, filters, and a complex-looking patch bay on the right hand side that is reminiscent of a breadboard. By inserting conductive pins, one can make connections between various inputs and outputs.

Internally the different features and circuits are mostly unconnected from one another by default, so the patch board is how the instrument is “programmed” and the connections made can be quite complex. The 4600 is one of a few synthesizer designs by [Trevor Marshall], who has some additional details about on his website.

The video (embedded below) is a complete walk-through of the unit, including its history, quirks, and design features. If you’d like to skip directly to a hands-on demonstrating how it works, that begins around the 10:15 mark.

Synthesizers have a rich DIY history and it’s fascinating to see an in-depth look at this one. And hey, if you like your synths complex and intimidating, do yourself a favor and check out the Starship One.

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