Author: Zoe Skyforest

3644 Articles

Build Yourself A Useful Resistor Decade Box

November 22, 2024 by 18 Comments

If you’ve ever worked with guitar pedals or analog audio gear, you’ve probably realized the value of a resistor decade box. They substitute for a resistor in a circuit and let you quickly flick through a few different values at the twist of a knob. You can still buy them if you know where to look, but [M Caldeira] decided to build his own.

At its core, the decade box relies on a number of 11-position rotary switches. Seven are used in this case—covering each “decade” of resistances, from 1 ohm to 10 ohm and all the way up to 1 megaohm. The 11 positions on each switch allows the selection of a given resistance. For example, position 7 on the 100 ohm switch selects 700 ohms, and adds it to the total resistance of the box.

[M Caldeira] did a good job of building the basic circuit, as well as assembling it in an attractive, easy-to-use way. It should serve him well on his future audio projects and many others besides. It’s a simple thing, but sometimes there’s nothing more satisfying than building your own tools.

We’ve seen other neat designs like this in the past, including an SMD version and this neat digital decade box. Video after the break.

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Enhiker Helps You Decide If Its A Good Day To Hike

November 22, 2024 by 10 Comments

Many of us check the weather before heading out for the day — we want to know if we’re dressed (or equipped) properly to handle what Mother Nature has planned for us. This is even more important if you’re going out hiking, because you’re going to be out in a more rugged environment. To aid in this regard, [Mukesh Sankhla] built a tool called Enhiker.

The concept is simple; it’s intended to tell you everything you need to know about current and pending conditions before heading out on a hike. It’s based around Unihiker, a single-board computer which also conveniently features a 2.8-inch touch screen. It’s a quad-core ARM device that runs Debian and has WiFi and Bluetooth built in, too. The device is able to query its GPS/GNSS receiver for location information, and then uses this to get accurate weather data online from OpenWeatherMap. It makes some basic analysis, too. For example, it can tell you if it’s a good time to go out, or if there’s a storm likely rolling in, or if the conditions are hot enough to make heat stroke a concern.

It’s a nifty little gadget, and it’s neat to have all the relevant information displayed on one compact device. We’d love to see it upgraded further with cellular connectivity in addition to WiFi; this would make it more capable when out and about.

We’ve seen some other neat hiking hacks before, too, like this antenna built with a hiking pole. Meanwhile, if you’ve got your own neat hacks for when you’re out on the trail, don’t hesitate to let us know!

Learn About Robot Arms By Building Pedro 2.0

November 22, 2024 by 25 Comments

Whether you’re a kid or a kid at heart, learning about science and engineering can be a lot more fun if it’s practical. You could sit around learning about motors and control theory, or you could build a robot arm and play with it. If the latter sounds like your bag of hammers, you might like Pedro 2.0.

Pedro 2.0 is a simple 3D-printable robot arm intended for STEAM education. If you’re new to that acronym, it basically refers to the combination of artistic skills with education around science, technology, engineering and mathematics.

The build relies on components that are readily available pretty much around the world—SG90 servo motors, ball bearings, and an Arduino running the show. There’s also an NRF24L01 module for wireless remote control. All the rest of the major mechanical parts can be whipped up on a 3D printer, and you don’t need a particularly special one, either. Any old FDM machine should do the job just fine if it’s calibrated properly.

If you fancy dipping your toes in the world of robot arms, this is a really easy starting point that will teach you a lot along the way. From there, you can delve into more advanced designs, or even consider constructing your own tentacles. The world really is your octopus oyster.

Custom Mouse Rocks Neat Thumbstick Design

November 21, 2024 by 20 Comments

A mouse is just two buttons, and a two-dimensional motion tracking system, right? Oh, and a scroll wheel. And a third button. And…now you’re realizing that mice can be pretty complicated. [DIY Yarik] proves that in spades with his impressive—and complex—mouse build. The only thing is, you might argue it isn’t really a mouse.

The inspiration for the mouse was simple. [Yarik] wanted something that was comfortable to use. He also wanted a mouse that wouldn’t break so often—apparently, he’s had a lot of reliability issues with mice in recent years. Thus, he went with a custom 3D-printed design with a wrist rest at the base. This allows his hand to naturally rest in a position where he can access multiple buttons and a central thumbstick for pointing. In fact, there’s a secondary scroll control and a rotary dial as well. It’s a pretty juicy control surface. Code is up on GitHub.

The use of a thumbstick is controversial—some might exclaim “this is not a mouse!” To them, I say, “Fine, call it a pointing device.” It’s still cool, and it look like a comfortable way to interface with a computer.

We’ve seen some other neat custom mice over the years, too, like this hilarious force-feedback mouse. Video after the break. Continue reading “Custom Mouse Rocks Neat Thumbstick Design” →

There’s Now A Wiki For Hacking Redbox Machines

November 21, 2024 by 11 Comments

With the rapidly evolving situation surrounding the Redbox vending machines still out in the wild, it’s about time somebody put together a Wiki to keep it all straight.

The unredbox wiki has information on the various different hardware revisions that Redbox put out into the wild, from the regular outdoor machines to the weird indoor blue variant. The site also has breakdowns on individual components. For example, it covers the computers inside the machines, built by Dell, Lenovo, and Premio, and bits and pieces like the DVD carousel and the modems used inside.

Basically, if you’re working with these machines and you don’t have a manual, this resource could help you out.  As could the neat video below that shows the internals of a Redbox machine during the reloading process.

Whatever you do, though, don’t steal the kiosks. There’s folks handling that already, you’re not allowed to just walk up and haul them away. Check out our earlier coverage of people that are still out there renting from these machines, too.

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Simple Hydrogen Generator Makes Bubbles And Looks Cool

November 21, 2024 by 18 Comments

Hydrogen! It’s a highly flammable gas that seems way too cool to be easy to come by. And yet, it’s actually trivial to make it out of water if you know how. [Maciej Nowak] has shown us how to do just that with his latest build.

The project in question is a simple hydrogen generator that relies on the electrolysis of water. Long story short, run a current through water and you can split H2O molecules up and make H2 and O2 molecules instead. From water, you get both hydrogen to burn and the oxygen to burn it in! Even better, when you do burn the hydrogen, it combines with the oxygen to make water again! It’s all too perfect.

This particular generator uses a series of acrylic tanks. Each is fitted with electrodes assembled from threaded rods to pass current through water. The tops of the tanks have barbed fittings which allow the gas produced to be plumbed off to another storage vessel for later use. The video shows us the construction of the generator, but we also get to see it in action—both in terms of generating gas from the water, and that gas later being used in some fun combustion experiments.

Pedants will point out this isn’t really just a hydrogen generator, because it’s generating oxygen too. Either way, it’s still cool. We’ve featured a few similar builds before as well.

(Pedantic editor’s note: Because this build doesn’t separate the H2 from the O2, what you get is a stoichiometric mix, or HHO, or “Oxyhydrogen“. By virtue of being in exactly the right ratio to combust, this stuff is significantly more explosive than pure H2. Be careful!)

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The Great Redbox Cleanup: One Company Is Hauling Away America’s Last DVD Kiosks

November 19, 2024 by 91 Comments

Remember Redbox? Those bright red DVD vending machines that dotted every strip mall and supermarket in America, offering cheap rentals when Netflix was still stuffing discs into paper envelopes? After streaming finally delivered the killing blow to physical rentals, Redbox threw in the towel in June 2024, leaving around 34,000 kiosks standing as silent monuments to yet another dead media format.

Last month, we reported that these machines were still out there, barely functional and clinging to life. Now, a company called The Junkluggers has been tasked with the massive undertaking of clearing these mechanical movie dispensers from the American retail landscape, and they’re doing it in a surprisingly thoughtful way. I chatted to them to find out how it’s going.

Continue reading “The Great Redbox Cleanup: One Company Is Hauling Away America’s Last DVD Kiosks” →