Automated musical instrument with LED array

ESP32 Is The Brains Behind This Art Installation

The ESP32 has enabled an uncountable number of small electronics projects and even some commercial products, thanks to its small size, low price point, and wireless capabilities. Plenty of remote sensors, lighting setups, and even home automation projects now run on this small faithful chip. But being relegated to an electronics enclosure controlling a small electrical setup isn’t all that these tiny chips can do as [Eirik Brandal] shows us with this unique piece of audio and visual art.

The project is essentially a small, automated synthesizer that has a series of arrays programmed into it that correspond to various musical scales. Any of these can be selected for the instrument to play through. The notes of the scale are shuffled through with some random variations, allowing for a completely automated musical instrument. The musical generation is entirely analog as well, created by some oscillators, amplifiers, and other filtering and effects. The ESP32 also controls a lighting sculpture that illuminates a series of LEDs as the music plays.

The art installation itself creates quite haunting, mesmerizing tunes that are illustrated in the video linked after the break. While it’s not quite to the realm of artificial intelligence since it uses pre-programmed patterns with some randomness mixed in, it does give us hints of some other projects that have used AI in order to compose new music.

Continue reading “ESP32 Is The Brains Behind This Art Installation”

Pinewood Derby Scale Measures CG

If you suffer from nostalgia, you might remember carving a block of wood into a car, adding some wheels, and racing it against other contestants in a pinewood derby. Today’s derby is decidedly high tech though, and we were impressed with this car scale that also figures out the car’s center of gravity.

Based on an Arduino, of course, along with a pair of HX711 load cells. Why a pair? That’s how the device measures the center of gravity is by weighing the front and rear of the car separately.

Continue reading “Pinewood Derby Scale Measures CG”

A Model Of Dry Humor

If you want to see a glorious combination of model bananas in a treehouse mixed with a lot of tongue-in-cheek humor, you will appreciate [Studson]’s build video. Video also after the break. He is making an homage to Donkey Kong 64 from 1999, which may be a long time ago for some folks’ memory (Expansion Pak). Grab a piece of your favorite banana-flavored fruit and sit tight for joke delivery as dry as his batch of baked bark.

The treehouse uses a mixture of found material and crafting supplies. In a colorful twist, all the brown bark-wielding sticks are green, while the decorative greenery came from a modeling store shelf. It all starts with a forked branch pruned from the backyard and a smooth-sided container lid that might make you look twice the next time you nuts are buying a bin of assorted kernels. If you thought coffee stirrers couldn’t be used outside their intended purpose, prepare to have your eyes opened, but remember to wear eye protection as some of the wood clippings look like they could achieve escape velocity. The key to making this look like an ape abode, and not a birdhouse, is the color choices and finishing techniques. Judging by the outcome and compared to the steps, making a model of this caliber is the sign of an expert.

If you wish to binge on wooden Donkey Kong, we can grant your desire, but if you prefer your treehouses life-sized, this may launch your imagination.

Continue reading “A Model Of Dry Humor”

Baby C-17 Sends Imaginations Soaring

The C-17 Globemaster III is a military cargo jet that can carry what their commercial counterparts can’t, to places those other planes can’t go. The people who keep these planes flying are proud of their capable airlifter, but it’s hard to show them off. Solution: build a scaled-down version more suitable for driving off base for a parade down Main Street and other community events.

While the real thing was built under an expensive and contentious military procurement process, the miniature was built with volunteer labor using castoff materials. The volunteer force included maintenance crew whose job is to know the C-17 inside and out. Combined with fabrication skills that comes with the job, the impressive baby plane faithfully copied many curvatures and details from full-sized originals. (Albeit with some alteration for its cartoony proportions.) Underneath are mechanicals from a retired John Deere Gator utility vehicle. They usually resemble a large golf cart except with a cargo bed and more rugged suspension. Basically they are to golf carts as a C-17 is to a 767. Amusingly, the little plane has its own rear loading ramp, superficially preserving the cargo-carrying capacity of the original Gator chassis.

Interior features continue, though the official picture gallery doesn’t show them. There is a flight deck with control panels and various sights and sounds to keep visitors entertained. Enough details were poured into the exhibit that some people had to ask if the little plane can fly, and the answer is a very definite no. The wings, and the engine pods mounted to them, are only for show carrying The Spirit of Hope, Liberty & Freedom. It is quite a long official name for such a short stubby thing.

We always love to admire impressively put-together miniatures, and not all projects require skill of aircraft mechanics. Like this very approachable miniature forklift project. But there are plenty of other projects whose skills put us in awe, like this remote-control car powered by a miniature V-10 engine.

[via The Museum of Flight]

3D-Printed Scale Model Of Perseverance Rover Seems As Complicated As The Real One

Sometimes the best way to figure out how something works is to make a model of it. 3D-modeling software makes it possible to do the job in silico, and sometimes that’s enough. But to really get inside the designer’s head, executing a physical model, like this quarter-scale RC-controlled Perseverance rover, is a great way to go.

If you’re looking for cutting-edge tech or groundbreaking design, this build will probably not light your fire. But a closer look will show not only great details about how JPL designs robots that can operate on Mars, but some great design and 3D-printing tips too. [Dejan]’s modeling process started with the 3D renderings of Perseverance available on the NASA website, which went into SolidWorks via Blender. [Dejan] was intent on capturing all the details of the rover, even those that ended up just for looks. But there’s plenty of functionality, too — the running gear looks and functions just like the six-wheel double-bogie design used on Perseverance, as well as Curiosity before it. This revealed an interesting fact that we didn’t previously realize — that the hull is suspended from a single pivot point on each side, while a linkage across the deck both prevents the body from pivoting and provides differential control of the drive bogies on either side of the rover.

The video below shows both the impressive amount of 3D printing needed to make all the model’s parts as well as the involved assembly process. It also shows the Arduino-controlled model being piloted around via radio control. There’s a lot to learn from this model, and [Dejan]’s craftsmanship here is top-notch too. We’ve seen such builds before from him, like this 3D-printed SCARA arm, a CNC hot-wire foam cutter, and an automated wire bender.

Continue reading “3D-Printed Scale Model Of Perseverance Rover Seems As Complicated As The Real One”

Homebrew Slide Rule Gets Back To Mathematical Basics

In the grand scheme of things, it really wasn’t all that long ago that a slide rule was part of an engineer’s every day equipment. Long before electronic calculators came along, a couple of sticks of wood inscribed with accurate scales was all it took to do everything from simple multiplication to logarithms and trig functions.

While finding a slide rule these days isn’t impossible, it’s still not exactly easy, and buying one off the shelf isn’t as fun or as instructive as building one yourself. [JavierL90]’s slide rule build started, ironically enough, on the computer, with a Python program designed to graphically plot the various scales needed for the fixed sections of the slide rules (the “stators”) and the moving bit (the “slide”).  His first throught was to laser-engrave the scales, but the route of printing them onto self-adhesive vinyl stock proved to be easier.

With the scale squared away, work turned to the mechanism itself. He chose walnut for the wood, aluminum for the brackets, and a 3D-printed frame holding a thin acrylic window for the sliding cursor. The woodworking is simple but well-done, as is the metalwork. We especially like the method used to create the cursor line — a simple line scored into the acrylic with a razor, which was then filled with red inks. The assembled slide rule is a thing of beauty, looking for all the world like a commercial model, especially when decked out with its custom faux leather carry case.

We have to admit that the use of a slide rule is a life skill that passed us by, but seeing this puts us in the mood for another try. We might have to start really, really simple and work up from there.

Cheap Lab Balance Needs Upgrades, Gets Gutted Instead

What is this world coming to when you spend seven bucks on a digital scale and you have to completely rebuild it to get the functionality you need? Is nothing sacred anymore?

Such were the straits [Jan Henrik] found himself in with his AliExpress special, a portable digital scale that certainly looks like it’s capable of its basic task. Sadly, though, [Jan] was looking for a few more digits of resolution and a lot more in the way of hackability. And so literally almost every original component was ripped out of the scale, replaced by a custom PCB carrying an STM32 microcontroller and OLED display. The PCB has a complicated shape that allows the original lid to attach to it, as well as the stainless steel pan and load cell. [Jan] developed new firmware that fixes some annoying traits, for example powering down after 30 seconds, and adds new functionality, such as piece-counting by weight. The video below shows some of the new features in action.

Alas, [Jan ] reports that even the original load cell must go, as it lacks the accuracy his application requires. So he’ll essentially end up building the scale from scratch, which we respect, of course. At this rate, he might even try to build his own load cell from SMD resistors too.

Continue reading “Cheap Lab Balance Needs Upgrades, Gets Gutted Instead”