These DIY Super Headphones Take Sound Seriously

October 1, 2023 by Donald Papp 2 Comments

[Pete Lewis] from SparkFun takes audio and comfort seriously, and recently shared details on making a customized set of Super Headphones, granting quality sound and stereo ambient passthrough, while providing hearing protection at the same time by isolating the wearer from the environment.

Such products can be purchased off the shelf (usually called some variant of “electronic hearing protection”), but every hacker knows nothing beats some DIY to get exactly the features one wants. After all, off-the-shelf solutions are focused on hearing protection, not sound quality. [Pete] also wanted features like the ability to freely adjust how much ambient sound was mixed in, as well as the ability to integrate a line-level audio source or Bluetooth input.

Early prototype of Super Headphones (click to enlarge)

On the surface the required components are straightforward, but as usual, the devil is in the details. Microphone selection, for example, required a lot of testing. A good microphone needed to be able to deal with extremely loud ambient sounds without distortion, yet still be sensitive enough to be useful. [Pete] found a good solution, but also muses that two sets of microphones (one for loud environments, and one for quieter) might be worth a try.

After several prototypes, the result is headphones that allow safe and loud band practice in a basement as easily as they provide high-quality music and situational awareness while mowing the lawn. Even so, [Pete]’s not done yet. He’s working on improving comfort by using photogrammetry to help design and 3D print custom-fitted components.

Powder Your Prints For Baby-Smoothness

September 24, 2023 by Kristina Panos 47 Comments

Layer lines are a dead giveaway to non-normies that a thing was 3D printed. There are things you can do to smooth them — sanding, chemical smoothing, and fillers come to mind. Although this technique technically uses all three, it starts with something very simple.

In the video after the break, [DaveRig] gets right to the point: baby powder and resin mixed together make a fine smoothing agent when cured. Having read about it online, he decided to give it a try.

Starting with a half sphere that had admittedly pretty big layer lines, [DaveRig] mixed up enough resin and baby powder to make the consistency of milk or cream. Then he put five coats on, curing and sanding with 120 in between each one.

Then it’s on to standard post-processing stuff. You know, wipe it down with alcohol, sand it a little more, wet sand, and then it’s on to the airbrush and clear-coat. The end result looks to be as smooth as your average bowling ball, as you can see in the main photo.

What’s your favorite post-processing method? Have you tried annealing them in salt?

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This Keyboard Doesn’t Work Without Game Boy Cartridges

September 11, 2023 by Kristina Panos 9 Comments

Just when we though we’d seen it all when it comes to custom keyboards (or most of it, anyway), along comes [Stu] with the TypeBoy and TypePak. Like the title implies, TypeBoy and TypePak are inseparable.

Let’s talk about TypePak first. Somehow, some way, [Stu] managed to fit the following into an aftermarket Game Boy Advance cartridge: a XIAO BLE microcontroller, a Sharp Memory Display, a shift register, and a LiPo battery. It’s all there in [Stu]’s incredibly detailed blog post linked above.

Amazing, no? And although [Stu] claims that the TypePak is mostly for aesthetics (boy howdy), it will make swapping microcontrollers much easier in the future.

If this looks sort of familiar, you may remember a likely render of [mujimaniac]’s board called the GIGA40 that also employed a cartridge system. Allegedly there is now a working prototype of the GIGA40.

Would you like to give the TypeBoy and TypePak a go? Files are available on GitHub, but this doesn’t seem like a project for the faint of heart.

Speaking of stuffing things in to Game Boy cartridges, check out this SNES cartridge turned hard drive enclosure.

Via KBD

3D-Printed Woven Coasters Save Tabletops In Style

August 20, 2023 by Kristina Panos 6 Comments

When regular people think of 3D printing, they likely imagine semi-newfangled objects like twisty vases and useless trinkets. But there is so much more to 3D printing, as [andrei.erdei]’s printed, woven coasters demonstrate.

The design is based on the stake and strand basket weaving technique, which uses rigid strips called stakes in one direction and thinner strips called strands in the other. Since the flexibility of PLA is questionable, [andrei] printed the stakes already bent in a square wave pattern that accommodates the strands fairly easily. To tie the coasters together and make them look more polished and commercial, [andrei] designed a holder as well.

The awesome thing about this technique is that you can do so much with it, like varying the stakes’ widths or making them diagonal instead of square. [andrei] designed these in Tinkercad using Codeblocks; of course, they are open source. Be sure to check out the assembly video after the break.

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All About USB-C: Example Circuits

August 7, 2023 by Arya Voronova 7 Comments

In the six months that have passed after the last USB-C article has been released, I have thought up a bunch of ways that these articles could have been improved. It’s, of course, normal to have such a feeling — expected, even. I now believe that there’s a few gaps that I could bridge. For instance, I have not provided enough example circuits, and sometimes one schematic can convey things better than a thousand words.

Let’s fix that! I’ll give you schematics for the kinds of USB-C devices you’re actually likely to want to build. I’ll also share a bunch of IC part numbers in this article, but I don’t have an exhaustive collection, of course – if you find more cool ICs that work for USB-C purposes and aren’t mentioned here, please do let us all know in the comments!

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Importing EAGLE Projects Into KiCad 7, And How To Fix Them

July 1, 2023 by Donald Papp 10 Comments

Migrating a PCB design from one CAD software package to another is no one’s favorite task. It almost never works cleanly. Often there are missing schematic symbols, scrambled PCB footprints, and plenty of other problems. Thankfully [shabaz] shows how to import EAGLE projects into KiCad 7 and fix the most common problems one is likely to encounter in the process. Frankly, the information couldn’t come at a better time.

This is very timely now that EAGLE has gone the way of the dodo. CadSoft EAGLE used to be a big shot when it came to PCB design for small organizations or individual designers, but six years after being purchased by Autodesk they are no more. KiCad 7 is a staggeringly capable open-source software package containing some fantastic features for beginner and advanced designers alike.

Of course, these kinds of tutorials tend to be perishable because software changes over time. So if you’re staring down a migration from EAGLE to KiCad and could use some guidance, there’s no better time than the present. [shabaz]’s video showing the process is embedded below.

Thanks to [problemchild68] for the tip!

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Smart Sphere Or Magnetic Magic

June 19, 2023 by Brian McEvoy 10 Comments

Sometimes a coworker sees something on your desk, and they have to ask, “Where can I get one of those?” and that has to be one of the greatest compliments to a maker. [Greg Zumwalt] nailed it with his “Marblevator Line Follower.” Roboticists will immediately recognize a black line on a white surface, but this uses hidden mechanics instead of light/dark sensors. Check out the video after the break to see the secrets, or keep bearing with us.

Inside the cylinder is a battery, charging circuit, inductive receiving coil, and a motor turning a magnet-laden arm beneath the cap. The overall effect is an illusion to convince people that the marble has a mind of its own. You can pick up the cylinder, and it keeps moving as expected from an autonomous bot. The black line is actually a groove, so the bearing follows a curvy course without any extra movements from the magnets within. The two-tone look is super-clean, but the whimsy of a “smart bearing” makes this an all-around winner.

“Marblevator Line Follower” is not the first Marblevator we featured, and we love our bouncing-bearing baubles and music-making machines.

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