Year: 2022

MIDI Controller Looks Good, Enables Your Air Guitar Habit

May 18, 2022 by 8 Comments

We all want to be guitar heroes, but most of us have to settle for letting a MIDI board play our riffs using a MIDI controller. [Joris] thinks a MIDI controller should look like a cool instrument and thus the Ni28 was born. Honestly, we first thought we were looking at wall art, but on closer look, you can see the fretboard and the soundhole are festooned with buttons.

Actually, they aren’t really buttons. The Ni in the name is because the buttons are nickel-plated brass plates that act like touch switches. There’s virtually no activation force required and you can easily touch more than one plate at a time.

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3D Printed Linear Actuator Is Cheap And Strong

May 18, 2022 by 29 Comments

Motors are all well and good for moving things, but they’re all about the round-and-round. Sometimes, you need to move something back and forth, and for that a linear actuator will do the trick. While they can be readily sourced for under $50 online, [Michael Rechtin] genuinely felt like reinventing the wheel, and managed to whip up a 3D-printed design that costs under 20 bucks.

The basic design is simple, consisting of a small motor which is geared down through several stages using simple spur gears. The last gear in the train is tasked with turning a lead screw which drives the arm of the linear actuator back and forward.

For simplicity, [Michael] used a 24V brushed DC gearmotor for its low cost and the fact it already has a step-down gearbox integrated into the design. It’s paired with a couple more 3D-printed spur gears to provide even more torque. Instead of a fancy lead screw, the build instead just uses a quarter-inch bolt sourced from Home Depot, which can be had much cheaper. This pushes a 3D-printed arm back and forth thanks to a nut stuck in the arm. It’s all wrapped up in a neat-and-tidy 3D-printed housing. The design is able to push with a force of roughly 220 lbs. For a more practical idea of its strength, it can readily crush an empty soda can.

The video on the design is great, showing how important features like limit switches are added, and how the wiring can be neatly hidden away inside the housing. We’ve seen [Michael’s] work before, too, like strength testing various types of 3D printed gears. Video after the break.

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Hackaday Prize 2022: Recycled Tire Table Is Where The Rubber Meets The Road

May 18, 2022 by 43 Comments

The problem with good inventions is that we usually end up with way too many of that particular widget lying around, which can cause all kinds of problems. Take the car tire, for instance. They were a great invention that helped spell the end of buggy whips and broken wagon wheels. But there are so many used-up tires about today that some people end up burning them in large piles, of all possible things.

Not [Vaibhav], who prefers to turn trash into utilitarian treasures. With little more than an old tire, some jute rope, and four plastic drink bottles, they made a sturdy, low-slung piece of furniture that could be used as a coffee table, a foot stool, or whatever life calls for.

Construction was fairly simple and involved stabilizing the hollow core with a round piece of cardboard glued to either side of the tire. Then came the jute rope and glue artistry, which hides any trace of the foundational materials. Finally, [Vaibhav] glued four plastic bottles to the bottom to act as legs. We think that steel cans would last longer and support more weight, but if plastic bottles are the only option, you could always fill them with dirt or sand.

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The Little Big Dogs Of Invention

May 18, 2022 by 53 Comments

This is a story about two dogs I know. It is also a story of the U.S. Navy, aviation, and nuclear weapons. Sometimes it is easy to see things in dogs or other people, but hard to see those same things in ourselves. It’s a good thing that dogs can’t read (that we know of) because this is a bit of an embarrassing story for Doc. He’s a sweet good-natured dog and he’s a rather large labradoodle. He occasionally visits another usually good-natured dog, Rocky — a sheltie who is much smaller than Doc.

I say Rocky is good-natured and with people, he is. But he doesn’t care so much for other dogs. I often suspect he doesn’t realize he’s a dog and he is puzzled by how other dogs behave. You would think that when Doc comes to visit, the big dog would lord it over the little dog, right? Turns out, Doc doesn’t realize he’s way bigger than Rocky and — apparently — Rocky doesn’t realize he should be terrified of Doc. So Rocky bullies Doc to the point of embarrassment. Rocky will block him from the door, for example, and Doc will sit quaking unable to muster the courage to pass the formidable Rocky.

Big Doc…
Somewhat smaller Rocky….

It makes you wonder how many times we could do something except for the fact that we “know” we can’t do it. Or we believe someone who tells us we can’t. Doc could barge right past Rocky if he wanted to and he could also put Rocky in his place. But he doesn’t realize that those things are possible.

You see this a lot in the areas of technology and innovation. Often big advances come from people who don’t know that the experts say something is impossible or they don’t believe them. Case in point: people were anxious to fly around the start of the 1900s. People had dreamed of flying since the dawn of time and it seemed like it might actually be possible. People like Alberto Santos-Dumont, the Wright brothers, Clément Ader, and Gustave Whitehead all have claimed that they were the first to fly. Others like Sir George Cayley, William Henson, Otto Lilienthal, and Octave Chanute were all experimenting with gliders and powered craft even earlier with some success.

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A self-service checkout computer game

Practice Your Shopping Skills With This Self-Service Checkout Game

May 18, 2022 by 13 Comments

Self-service checkouts have become a common feature in supermarkets the world over, a trend accelerated by the coronavirus pandemic. While some may lament the loss of human contact, others relish the opportunity to do their own scanning: with a bit of practice, self-service can provide for a very fast checkout experience. Assuming, of course, that the machine recognizes each product, the built-in weight sensor works correctly, and you don’t get selected for a random check.

If you want to practice your checkout game without spending loads of money, you might want to have a look at [Niklas Roy] and [Kati Hyyppä]’s latest project: Bonprix is a game where the goal is to scan as many items as possible within a 90-second time limit. Installed at the Eniarof DIY festival, it’s designed to resemble a typical supermarket checkout with a display, a barcode scanner and a shopping basket filled with random items. The screen indicates which item should be scanned next; if you’re too slow, the checkout will begin to offer discounts, which you obviously don’t want. When the 90 seconds are over, the machine spits out a receipt indicating your total score.

The checkout desk is made from wooden pallets and cardboard; inside is a laptop running Linux, with a handheld barcode scanner attached via USB. An LED strip provides a beam of bright red light to indicate the scanning area, and turns green when a barcode is successfully scanned. Arduinos control the LEDs and the big red-and-yellow “start” button, while a thermal printer from an ATM prints the receipts at the end of each game.

Apart from a bit of fun, the Bonprix project tries to address questions relating to consumer culture and self-checkouts: is it fair to let customers do their own work? Should they be paid for it? Is it even ethical to encourage people to spend as much as possible?

While this is the first time we’ve seen a self-service checkout computer game, we’ve done a few deep dives into the fascinating technology of barcodes that makes it all possible. Check this out!

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Natural Language AI In Your Next Project? It’s Easier Than You Think

May 18, 2022 by 25 Comments

Want your next project to trash talk? Dynamically rewrite boring log messages as sci-fi technobabble? Happily (or grudgingly) answer questions? Doing that sort of thing and more can be done with OpenAI’s GPT-3, a natural language prediction model with an API that is probably a lot easier to use than you might think.

In fact, if you have basic Python coding skills, or even just the ability to craft a curl statement, you have just about everything you need to add this ability to your next project. It’s not free in the long run, although initial use is free on signup, but for personal projects the costs will be very small.

Basic Concepts

OpenAI has an API that provides access to GPT-3, a machine learning model with the ability to perform just about any task that involves understanding or generating natural-sounding language.

OpenAI provides some excellent documentation as well as a web tool through which one can experiment interactively. First, however, one must create an account and receive an API key. After that is done, the doors are open.

Creating an account also gives one a number of free credits that can be used to experiment with ideas. Once the free trial is used up or expires, using the API will cost money. How much? Not a lot, frankly. Everything sent to (and received from) the API is broken into tokens, and pricing is from $0.0008 to $0.06 per thousand tokens. A thousand tokens is roughly 750 words, so small projects are really not a big financial commitment. My free trial came with 18 USD of credits, of which I have so far barely managed to spend 5%.

Let’s take a closer look at how it works, and what can be done with it!

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Sunrise Keyboard Looks The Part

May 18, 2022 by 9 Comments

If you’ve been to a bar sometime since the 1930s, you’ve probably spied someone drinking a Tequila Sunrise. It’s a drink that mimics the beautiful colors of the dawn. In much the same way, so does this Sunriser keyboard build from [crashl1445].

Built for a high-school engineering project, the build looks resplendent with its yellow case, paired with yellow, orange and pink keycaps to produce the wonderful sunrise aesthetic. The build relies on an Elite-C v4 microcontroller, an off-the-shelf device specifically designed for building custom keyboards. As you might guess from the name, it features a USB-C port, serving as a modernized alternative to the Arduino Pro Micro for custom keyboard builders. KTT Rose switches are used as per [crashl1445’s] own preference, and there’s even a rotary encoder which acts as a volume knob, installed right by the arrow keys. The case is printed in several parts on a Prusa Mk3+, as the keyboard wouldn’t fit entirely on the build plate as a single piece.

The best thing about building your own keyboard is that you can design it entirely to suit your own preferences and aesthetic; we think [crashl1445] did a great job in this regard. If you’re cooking up your own sweet keyboard build, don’t hesitate to let us know!