Remote-Control Kinetic Sand Table Uses A Single Arduino

January 7, 2024 by Kristina Panos 11 Comments

There’s nothing fun about a Sisyphean task unless you’re watching one being carried out by someone or something else. In that case, it can be mesmerizing like this Arduino-driven kinetic sand table.

What you can’t see. Image via [thang010146] on YouTube

Like many of these builds, it all started with an ordinary coffee table from the hacker’s favorite furnitüre store. [NewsonsElectronics] opened it up and added a 3mm-thick board to hold the sand and another to hold the rails and magnets.

After designing some pieces to connect the rails and pulleys together, [NewsonsElectronics] let the laser cutter loose on some more 3mm stock. A pair of stepper motors connected to a CNC shield do all of the work, driving around a stack of magnets that causes the ball bearing to trudge beautifully through the sand.

Be sure to check out the videos after the break. The first is a nice demonstration, and the second is the actual build video. In the third video, [NewsonsElectronics] explains how they could write the world’s smallest GRBL code to swing this with a single Arduino. Hint: it involves removing unnecessary data from the g-code generated by Sandify.

Don’t have a laser cutter? Here’s a sand table built from 3D printer parts.

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1D Fireworks Are Nice And Quiet

January 6, 2024 by Kristina Panos 17 Comments

Maybe you do it out of respect for the dogs and parents of young children in the neighborhood. Or maybe you do it because they’re harmful to the environment, or just because it’s too darn cold outside. Whatever your reasoning for not setting off fireworks, don’t fret — you can probably put together your own silent one-dimensional “fireworks” display from what you’ve got in the parts bin.

[Daniel Westhof]’s design is simple, requiring little more than a Wemos D1 Mini and a strip of WS2812 LEDs. Once activated, a red rocket shoots up from the ground and detonates, sending lights in both directions on the strip to imitate the bombs bursting in air. It’s controlled with a small push button switch, and there’s a deliciously large red LED indicator that shows the thing is ready for detonation.

You might be surprised to find that there’s a wide array of 1D gaming and animation projects out there, many of which made possible by the ubiquitous addressable RGB LED strip. We’ve seen a dungeon crawler, at least two different versions of the classic PONG, and even the makings of a simplified Wolfenstein.

3D Printed Eel Could Cost Less At Scale

January 6, 2024 by Kristina Panos 38 Comments

Be it a matter of cost, principle, or just plain being landlocked, the idea of 3D printed vegan eel over the real deal is quite an attractive development. An Israeli company called Steakholder Foods has introduced this very thing — something they claim is the world’s first plant-based, printed eel.

One thing to note about eel is that they are quite intricately textured, a problem which seems tailored for 3D printing. The company say they achieve similarity through precise layering and “a unique combination of materials”, which are proprietary. Although the current product is based solely on plant materials, the plan is to incorporate eel cells in the future. Right now, the company is looking to collaborate by providing printers and ink so that participants can create short-term revenue.

While it’s unclear whether the eel is printed and then cooked, or print-cooked like this chicken, it sure looks tasty. Would you eat printed food? Have you done so already? Let us know in the comments.

3D Printed Cookies, Sort Of

January 5, 2024 by Kristina Panos 1 Comment

Are there any cookies that taste better than the ones you make yourself? Well, maybe, but there’s a certain exquisite flavoring to effort. Just ask [jformulate], who created these custom chocolate-topped butter cookies using a mixture of 3D printing, silicone, and of course, baking and tempering.

[jformulate] did this project along with a makerspace group, and the first thing they did was decide on some images for the cookies. Once a hexagon-shaped mold was created in Fusion360, the images were added in. Some had to be height-adjusted in order for the detail to come out.

Once these positives were printed, it was time to make the food-safe silicone molds that would form the custom chocolate toppers. If you don’t have a vacuum de-gasser, [jformulate] recommends pouring a thin stream from a high place to avoid air bubbles. You can always tap the mold several times on a flat surface as well to bring trapped air to the top.

Finally, it’s time to make cookies. [jformulate] has good instructions for tempering chocolate, as well as a recipe for the butter cookies that support the designs. As a bonus, [jformulate] shows how to make a fish-shaped hot chocolate bomb, and made Jolly Rancher (sadly not Wrencher) medallions using the silicone molds and a microwave.

For the semi-disappointed, directly 3D printing cookies is definitely a thing.

The ScottoKatana Keyboard Is Cutting-Edge

January 5, 2024 by Kristina Panos 9 Comments

The lovely thing about a hobby like keyboard building is that the melting pot of designs manages to never turn into a nasty porridge. Rather, it remains a tasty chili that keeps getting more flavorful with time. It’s a simple recipe, really; someone becomes dissatisfied enough with their peripherals to do something about it, often trying various designs until they either settle on one, or come up with yet another awesome variant that suits their needs — and possibly someone else’s down the line.

The inimitable [Joe Scotto] has happened upon the katana layout, which has an inverse left-hand row stagger that lends symmetry to the design, and Scotto-ized it into a 33-key build that he says is the best-sounding one yet with lubed Gateron Milky Yellows.

The case and the keycaps are both 3D-printed, and as with all Scotto builds, it is beautifully hand-wired. This one uses an RP2040 Pro Micro, but an ATMega Pro Micro will work, too.

Everything is available on GitHub, and [Joe] promises a typing test soon, as well as a gasket version that foregoes the integrated plate.

Do you need a fast keyboard? Like, ridiculously fast? Then you should use an FPGA.

Via KBD and Make:

Flashlight Door Lock Is A Bright Idea

December 29, 2023 by Kristina Panos 45 Comments

There are many ways to lock a door. You could use a keypad, an RFID card, a fingerprint or retina scan, Wi-Fi, Bluetooth, the list goes on. You could even use a regular old metal key. But none of these may be as secure as [mircemk]’s Arduino-based door lock that employs a smartphone’s flashlight as a pass code.

At first blush, this seems horribly insecure. Use a plain old flashlight to open a door? Come on. But the key is in the software. In fact, between the typed-in pass code and the flash of light it generates, this lock kind of has two layers of security.

Here’s what’s going on: inside the accompanying smart phone application, there’s a list of passwords. Each of these passwords corresponds to a flash of light in milliseconds. Enter the correct password to satisfy the Arduino, and the phone’s flashlight is activated for the appropriate number of milliseconds to unlock the door.

As you’ll see in the video below, simply flashing the light manually doesn’t unlock the door, and neither does entering one of the other, bogus passwords. Although it does activate the flashlight each time, they don’t have the appropriate light-time length defined.

Hardware-wise, there is an Arduino Nano Every in charge of the LDR module that reads the flashlight input and the 12 V relay that unlocks the door. Be sure to check it out it the video after the break.

If you want to keep your critters from bringing wild critters back inside, check out this Wi-Fi cat door that lets you have a look at what might be dangling from their jaws before unlocking the door.

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Liftoff! The Origin Of The Countdown

December 27, 2023 by Kristina Panos 18 Comments

What’s the most thrilling part of rocketry? Well, the liftoff, naturally. But what about the sweet anticipation in those tense moments leading up to liftoff? In other words, the countdown. Where did it come from?

Far from being simply a dramatic device, the countdown clock serves a definite purpose — it lets the technicians and the astronauts synchronize their actions during the launch sequence. But where did the countdown — those famed ten seconds of here we go! that seem to mark the point of no return — come from? Doesn’t it all seem a little theatrical for scientists?

It may surprise you to learn that neither technicians nor astronauts conceived of the countdown. In their book, “Lunar Landings and Rocket Fever: Rediscovering Woman in the Moon”, media scholars Tom Gunning and Katharina Loew reveal that a little-known Fritz Lang movie called Woman In the Moon both “predicted the future of rocketry” and “played an effective role in its early development”.

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