Physically Huge SD Card Technically Has Some Benefits

January 24, 2021 by Lewin Day 27 Comments

SD cards were developed and released just before the turn of the millenium. Since then, we’ve seen smaller formats, miniSD and microSD, become popular for portable devices. However, sometimes bigger is better. [Useless Mod] dared to dream that dream, and put together a (physically) gigantic SD card.

In card is a full 10x scale reproduction of a SanDisk Extreme Pro SD card, complete with packaging, too. Built out of layers of laser cut MDF, it’s spray painted and given a high-quality label to complete the effect. The write protect slider instead serves in this case as a latch to open the assembly. Inside, there’s a simple regular SD card slot, wired up to the bigger card’s giant contacts made with copper tape. These interface with an huge 10x scale SD card slot, which acts as an adapter, allowing the giant SD to be used with regular hardware like cameras.

The giant SD might seem silly, but it has plenty of useful features. There’s flashing LEDs behind the label that make it easy to find if you drop it, along with an Apple Watch hidden inside that means it can be located using the Find My iPhone service. We’d have loved if it featured a RAID array full of 10 or more SD cards, as well, just to justify its enormous size. That said, [Useless Mod] points out that it’s big enough to keep a DSLR dry in a rainstorm when fitted to the hotshoe, so there’s that.

It’s a fun build, not a serious one, but one that we enjoyed on its merits. We suspect that, regardless of the card inside, you’ll have little luck recording at 4K with such long wire lengths in play. If you’ve ever had more normal compatability problems with the format, consider that it could be size causing your issues. Video after the break.

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Collapsible Pattern Projector Is A Bright Idea

January 24, 2021 by Kristina Panos 13 Comments

It’s fantastic that we’re living in the age of downloadable PDF patterns, it really is. But printing out a bunch of sheets of paper and taping them together is a tedious and tiresome process that can introduce error right from the start. This goes for any type of pattern, from sewing to R/C planes.

[Quinn]’s quarantine project is designed to cover both of those and everything in between. It’s a pattern projector made from stuff already on hand — a couple of offset projectors to scavenge parts from, and a large, trapezoidal mylar mirror from an old rear projection TV. At maximum zoom it projects a 4′ x 3′ image onto the tabletop, which sounds perfect for a whole lot of sewing patterns. At minimum zoom, the projected image fits on a foam core board.

We love that this dreamy setup can be stowed away so easily on hooks in the ceiling. [Quinn] had to perform a few hacks to make it all work together, including fabricating a bracket and some adjustable ties to hold the mirror aloft at just the ~~right~~ correct angle.

Need something smaller? Check out this Pi-powered pocket projector. Want a cinema-quality setup? You just have to find the right auctions.

A Big Set Of Logic Gates For Teaching The Basics

January 24, 2021 by Lewin Day 22 Comments

Teaching students about logic gates is often done in two parts, once on the whiteboard for the theory, and again on the breadboard for the practice. [shurik179] wasn’t a fan of the abstraction between easy-to-understand symbols on the whiteboard, and small IC packages full of many gates in reality. Instead, he built a set of real-world logic gates that can be wired together as a teaching tool.

Each “gate’ consists of a PCB roughly the size of a business card that features LEDs to indicate the state of its inputs and outputs, and a silkscreen indicating the name and symbol of the gate in question. There’s also a master PCB, which features three seed values, A, B, and C, to feed into the system. Students can set these values to 1 or 0, and feed them into the gates, which are wired together with 3-conductor servo cables, and observe the input on the built-in LEDs.

It’s a great way to demonstrate logic gates in the classroom. The design also allows the PCBs to be flipped over to show the actual electronic components responsible for implementing the logic, serving as a great bridge towards better understanding of real electronic design. Of course, it’s not the only way to learn – even Fallout 4 has a fully fledged logic toolkit these days!

RGB Glasses Built From PCBs

January 16, 2021 by Lewin Day 8 Comments

Shutter shades were cool once upon a time, but if you really want to stand out, it’s hard to go past aggressively bright LEDs right in the middle of your face. A great way to achieve that is by building a pair of RGB glasses, as [Arnov Sharma] did.

The design intelligently makes use of PCBs to form the entire structure of the glasses. One PCB makes up the left arm of the glasses, carrying an ESP12F microcontroller and the requisite support circuitry. It’s fitted to the front PCB through a slot, and soldered in place. The V+, GND, and DATA connections for the WS2812B LEDs also serve as the mechanical connection. The right arm of the glasses is held on in the same way, being the same as the left arm PCB but simply left unpopulated. A little glue is also used to stiffen up the connection.

It’s a tidy build, and one that can be easily controlled from a smartphone as the ESP12F runs a basic webserver which allows the color of the glasses to be changed. It’s not the first time we’ve seen a flashy pair of LED shades either! Video after the break.

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DIY LEGO Record Cleaner Is Revolutionary

January 16, 2021 by Kristina Panos 31 Comments

There are many schools of thought when it comes to keeping vinyl records clean. It’s a ritual that’s nearly as important as the one that comes after it — queuing up the record and lowering the needle. We’ve seen people use everything from Windex and microfiber towels to ultrasonic cleaning machines that cost hundreds or even thousands. In the midst of building a beefier ultrasonic record cleaner and waiting for parts, [Baserolokus] looked around at all the LEGO around the house and decided to build a plastic prototype in the interim.

The idea behind ultrasonic cleaning is simple — high-frequency sound waves pumped through distilled water produce tons of tiny bubbles. These bubbles gently knock all the dirt and grime out of the grooves without using any brushes, rags, or harsh cleaners. [Baserolokus] built two pieces that hang on the edge of a washtub. On one side, a Technic motor spins the record at just under one RPM, it spins against a 3D printer wheel embedded in the other side. Check it out in action after the break.

Cleaning your vinyl is a great first step, but you might be ruining your records with a sub-par turntable. Take a deep dive with [Jenny List]’s thorough primer on the subject.

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Interference Patterns Harnessed For Optical Logic Gates

January 16, 2021 by Dan Maloney 16 Comments

The basics of digital logic are pretty easy to master, and figuring out how the ones and zeroes flow through various kinds of gates is often an interesting exercise. Taking things down a level and breaking the component AND, OR, and NOR gates down to their underlying analog circuits adds some complexity, but the flow of electrons is still pretty understandable. Substitute all that for photons, though, and you’ll enter a strange world indeed.

At least that’s our take on [Jeroen Vleggaar]’s latest project, which is making logic gates from purely optical components. As he himself admits in the video below, this isn’t exactly unexplored territory, but his method, which uses constructive and destructive interference, seems not to have been used before. The basic “circuit” consists of a generator, a pair of diffraction patterns etched into a quartz plate, and an evaluator, which is basically a pinhole in another plate positioned to coincide with the common focal point of the generator patterns. An OR gate is formed when the two generators are hit with in-phase monochromatic light. Making the two inputs out of phase by 180° results in an XOR gate, as destructive interference between the two inputs prevents any light from making it out of the evaluator.

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Lego Tank Fires Soccer Ball Cannon

January 15, 2021 by Lewin Day 5 Comments

Back in the 20th century, Lego Technic was a popular toy designed to teach kids about mechanical technology, and be a lot of fun to boot. Motors and pneumatics were available, but by and large you had to move your creations and make the noises yourself. That’s not the case these days, as the [Brick Experiment Channel] demonstrates with this impressive Lego tank.

The drivetrain is straightforward, using standard Lego tank treads with each side given its own motor for easy skid steering. However, the real party piece is the slingshot cannon, which launches Lego soccer balls at 60 km/h. Utilizing several motors, it’s complete with elevation adjustment for accurate ranging, and a 6 round magazine so you can (slowly) prosecute your targets with rounds downrange.

What really makes this build great is the control system, with the tank being controlled by a PS4 controller via Sbrick, a device that lets Lego motors be controlled via Bluetooth. We’d love to build a couple of Lego vehicles and have them blast away at each other. We’ve seen the technology used before for a secret heist robot. Video after the break.

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