Lithium-Ion Batteries Are Easy To Find

October 3, 2022 by Arya Voronova 43 Comments

In the first article, I’ve given you an overview of Lithium-Ion batteries and cells as building blocks for our projects, and described how hackers should treat their Lithium-Ion cells. But what if you don’t have any LiIon cells yet? Where do you get LiIon cells for your project?

Taking laptop batteries apart, whether the regular 18650 or the modern pouch cell-based ones, remains a good avenue – many hackers take this road and the topic is extensively covered by a number of people. However, a 18650 cell might not fit your project size-wise, and thin batteries haven’t quite flooded the market yet. Let’s see what your options are beyond laptops. Continue reading “Lithium-Ion Batteries Are Easy To Find” →

Picture showing the way the cut-down piece of chip is soldered onto the mainboard - looking, indeed, like a QFN package.

Making A Handheld NES By Turning DIP Chips Into…QFN?

October 2, 2022 by Arya Voronova 51 Comments

You can achieve a lot with a Dremel. For instance, apparently you can slim the original NES down into the hand-held form-factor. Both the CPU and the PPU (Picture Processing Unit) are 40-pin DIP chips, which makes NES minification a bit tricky. [Redherring32] wasn’t one to be stopped by this, however, and turned these DIP chips into QFN-style-mounted dies (Nitter) using little more than a Dremel cutting wheel. Why? To bring his TinyTendo handheld game console project to fruition, of course.

DIP chip contacts go out from the die using a web of metal pins called the leadframe. [Redherring32] cuts into that leadframe and leaves only the useful part of the chip on, with the leadframe pieces remaining as QFN-like contact pads. Then, the chip is mounted onto a tailored footprint on the TinyTendo PCB, connected to all the other components that are, thankfully, possible to acquire in SMD form nowadays.

This trick works consistently, and we’re no doubt going to see the TinyTendo being released as a standalone project soon. Just a year ago, we saw [Redherring32] cut into these chips, and wondered what the purpose could’ve been. Now, we know: it’s a logical continuation of his OpenTendo project, a mainboard reverse-engineering and redesign of the original NES, an effort no doubt appreciated by many a NES enthusiast out there. Usually, people don’t cut the actual chips down to a small size – instead, they cut into the mainboards in a practice called ‘trimming’, and this practice has brought us many miniature original-hardware-based game console builds over these years.

Continue reading “Making A Handheld NES By Turning DIP Chips Into…QFN?” →

In A Way, 3D Scanning Is Over A Century Old

October 2, 2022 by Donald Papp 23 Comments

In France during the mid-to-late 1800s, one could go into François Willème’s studio, sit for a photo session consisting of 24 cameras arranged in a circle around the subject, and in a matter of days obtain a photosculpture. A photosculpture was essentially a sculpture representing, with a high degree of exactitude, the photographed subject. The kicker was that it was both much faster and far cheaper than traditional sculpting, and the process was remarkably similar in principle to 3D scanning. Not bad for well over a century ago.

This article takes a look at François’ method for using the technology and materials of the time to create 3D reproductions of photographed subjects. The article draws a connection between photosculpture and 3D printing, but we think the commonality with 3D scanning is much clearer.

Continue reading “In A Way, 3D Scanning Is Over A Century Old” →

Hackaday Links: October 2, 2022

October 2, 2022 by Dan Maloney 22 Comments

“Necessity is the mother of invention,” or so the saying goes. We’ve never held to that, finding that laziness is a much more powerful creative lubricant. And this story about someone who automated their job with a script is one of the best examples of sloth-driven invention since the TV remote was introduced. If we take the story at face value — and it’s the Internet, so why wouldn’t we? — this is a little scary, as the anonymous employee was in charge of curating digital evidence submissions for a law firm. The job was to watch for new files in a local folder, manually copy them to a cloud server, and verify the file with a hash to prove it hasn’t been tampered with and support the chain of custody. The OP says this was literally the only task to perform, so we can’t really blame them for automating it with a script once COVID shutdowns and working from home provided the necessary cover. But still — when your entire job can be done by a Windows batch file and some PowerShell commands while you play video games, we’re going to go out on a limb and say you’re probably underemployed.

People have been bagging on the US Space Force ever since its inception in 2019, which we think is a little sad. It has to be hard being the newest military service, especially since it branched off of the previously newest military service, and no matter how important its mission may be, there’s still always going to be the double stigmas of being both the new kid on the block and the one with a reputation for digging science fiction. And now they’ve given the naysayers yet more to dunk on, with the unveiling of the official US Space Force service song. Every service branch has a song — yes, even the Army, and no, not that one — and they all sound appropriately martial. So does the Space Force song, but apparently people have a problem with it, which we really don’t get at all — it sounds fine to us.

Continue reading “Hackaday Links: October 2, 2022” →

Rib Cage Lamp Kicks It Up A Notch With Party Mode

October 1, 2022 by Donald Papp 8 Comments

We think [Michelle]’s sound-reactive rib cage lamp turned out great, and the photos and details around how it was made are equally fantastic. The lamp is made of carved and waxed wood, and inside is a bundle of LED lighting capable of a variety of different color palettes and patterns, including the ability to react to sound. Every rib cage should have a party mode, after all.

The LED strip is fashioned into an atom-like structure.

Turns out that designing good rib cage pieces is a bigger challenge than one might think. [Michelle]’s method was to use an anatomical 3D model as reference, tracing each piece so that it could be cut from a flat sheet of wood.

The resulting flat pieces then get assembled into a stack, with each rib pointed downward at a roughly 20 degree angle. This process is a neat hack in itself: instead of drilling holes all at exactly the same angle, [Michelle] simply made the holes twice the diameter of the steel rod they stack on. The result? The pieces angle downward on their own.

The LED lighting is itself a nice piece of work. The basic structure comes from soldered solid-core wire. The RGB LED strip gets wound around that, then reinforced with garden wire. The result is an atomic-looking structure that sits inside the rib cage. An ESP32 development board drives everything with the FastLED library.

Code for everything, including the sound-reactive worky bits, which rely on an INMP441 I²C microphone module is all available on GitHub. And if you want to make your own sound-reactive art, make sure to check out these arms as well.

Want to see the rib cage in action? A short demo video is embedded below that demonstrates the sound reactivity. Equally applicable to either party or relaxation modes, we think.

Continue reading “Rib Cage Lamp Kicks It Up A Notch With Party Mode” →

DIY Wind Tunnel Aims To Educate The Youth

October 1, 2022 by Lewin Day 20 Comments

Typically, when we talk about wind tunnels, we think of the big facilities in use by the aerospace and motorsports industries. However, there’s nothing stopping you building a wind tunnel of your very own, and it may even be easier than you think! [Jude Pullen] has whipped up just such a design with DIY in mind.

Intended for high school Design & Technology (D&T) classes, it uses relatively simple materials construction techniques. The airflow straightener is built out of PVC pipes, and the end boxes built out of cardboard. The transparent walls for observation are created out of acrylic, while a simple fan provides the necessary flow. The desk-sized wind tunnel can then be instrumented with a manometer, tachometer, and anemometer to measure pressure, fan speed, and wind speed. [Jude] also explores experiments that can be run in the wind tunnel, such as working with a small balsa wood glider and measuring the lift it generates with a scale.

[Jude] has a very pragmatic and real-world understanding of such projects, too. He notes the difference between making things to measure, and making them to fit, and highlights the values of both approaches. It’s a much more holistic approach than simply berating students to “do it right” or “do it better” when making things in a D&T class.

Use of a basic wind tunnel is often not taught to engineering students until at least the second or third year of an engineering degree, after all the boring math and static analysis has been dealt with. However, there’s no reason high school physics students can’t understand the physics involved, and they’re more than capable of undertaking such a build. Starting such education early often nets huge benefits for individuals and their eventual careers.

Once you’ve got yourself a wind tunnel, you might want to start thinking about some flow visualization, which gets really exciting.

Continue reading “DIY Wind Tunnel Aims To Educate The Youth” →

Unintentional Emissions

October 1, 2022 by Elliot Williams 40 Comments

First, it was the WiFi router: my ancient WRT54G that had given me nearly two decades service. Something finally gave out in the 2.4 GHz circuitry, and it would WiFi no more. Before my tears could dry, our thermometer went on the fritz. It’s one of those outdoor jobbies that transmits the temperature to an indoor receiver. After that, the remote for our office lights stopped working, but it was long overdue for a battery change.

Meanwhile, my wife had ordered a new outdoor thermometer, and it too was having trouble keeping a link. Quality control these days! Then, my DIY coffee roaster fired up once without any provocation. This thing has worked quasi-reliably for ten years, and I know the hardware and firmware as if I had built them myself – there was no way one of my own tremendously sophisticated creations would be faulty. (That’s a joke, folks.) And then the last straw: the batteries in the office light remote tested good.

We definitely had a poltergeist, a radio poltergeist. And the root cause would turn out to be one of those old chestnuts from the early days of CMOS ICs – never leave an input floating that should have a defined logic level. Let me explain.

The WRT54G was the hub of my own home automation system, an accretion of ESP8266 and other devices that all happily speak MQTT to each other. When it went down, none of the little WiFi nodes could boot up right. One of them, described by yours truly in this video, is an ESP8266 connected to a 433 MHz radio transmitter. Now it gets interesting – the thermometers and the coffee roaster and the office lights all run on 433 MHz.

Here’s how it went down. The WiFi-to-433 bridge failed to connect to the WiFi and errored out before the part of the code where it initialized GPIO pins. The 433 MHz transmitter was powered, but its digital input was left flopping in the breeze, causing it to spit out random data all the time, with a pretty decent antenna. This jammed everything in the house, and apparently even once came up with the command to turn on the coffee roaster, entirely by chance. Anyway, unplugging the bridge fixed everything.

This was a fun one to troubleshoot, if only because it crossed so many different devices at different times, some homebrew and some commercial, and all on different control systems. Until I put it together that everything on 433 MHz was failing, I hadn’t even thought of it as one event. And then it turns out to be a digital electronics classic – the dangling input!

Anyway, hope you enjoyed the ride. And spill some copper for the humble pull-down resistor.