Office Supplies Make Math Sculptures If You Know What You’re Doing

July 17, 2024 by Lewin Day 7 Comments

Ever been fiddling around at your desk in the office, wondering if some grander structure might come from an assemblage of paper clips, pens, and binder clips? You’re not alone. Let your mind contemplate these beautiful maths sculptures from [Zachary Abel].

[Zachary] has a knack for both three-dimensional forms and the artistic use of color. His Möbius Clips sculpture ably takes 110 humble pieces of office equipment in multiple colors, and laces them into a continuous strip that has beguiled humanity for generations. The simple paper clip becomes a dodecahedron, a colorful spiralling ball, or a tightly-stitched box. He does great things with playing cards too.

What elevates his work is that there’s a mathematical structure to it. It’s so much more than a pile of stationary, there’s always a geometry, a pattern which your mind latches on to when you see it. He also often shares the mathematical background behind his work, too.

If you’re fumbling about with the contents of your desk drawer while another Zoom meeting drags on, you might want to challenge yourself to draw from [Zachary’s] example. If you pull off something fantastical, do let us know!

Playing Rock, Paper Scissors With A Time Of Flight Sensor

July 16, 2024 by Lewin Day 3 Comments

You can do all kinds of wonderful things with cameras and image recognition. However, sometimes spatial data is useful, too. As [madmcu] demonstrates, you can use depth data from a time-of-flight sensor for gesture recognition, as seen in this rock-paper-scissors demo.

If you’re unfamiliar with time-of-flight sensors, they’re easy enough to understand. They measure distance by determining the time it takes photons to travel from one place to another. For example, by shooting out light from the sensor and measuring how long it takes to bounce back, the sensor can determine how far away an object is. Take an array of time-of-flight measurements, and you can get simple spatial data for further analysis.

The build uses an Arduino Uno R4 Minima, paired with a demo board for the VL53L5CX time-of-flight sensor. The software is developed using NanoEdge AI Studio. In a basic sense, the system uses a machine learning model to classify data captured by the time-of-flight sensor into gestures matching rock, paper, or scissors—or nothing, if no hand is present. If you don’t find [madmcu]’s tutorial enough, you can take a look at the original version from STMicroelectronics, too.

It takes some training, and it only works in the right lighting conditions, but this is a functional system that can determine real hand sign and play the game. We’ve seen similar techniques help more advanced robots cheat at this game before, too! What a time to be alive.

CUDA, But Make It AMD

July 16, 2024 by Lewin Day 40 Comments

Compute Unified Device Architecture, or CUDA, is a software platform for doing big parallel calculation tasks on NVIDIA GPUs. It’s been a big part of the push to use GPUs for general purpose computing, and in some ways, competitor AMD has thusly been left out in the cold. However, with more demand for GPU computation than ever, there’s been a breakthrough. SCALE from [Spectral Compute] will let you compile CUDA applications for AMD GPUs.

SCALE allows CUDA programs to run as-is on AMD GPUs, without modification. The SCALE compiler is also intended as a drop-in swap for nvcc, right down to the command line options. For maximum ease of use, it acts like you’ve installed the NVIDIA Cuda Toolkit, so you can build with cmake just like you would for a normal NVIDIA setup. Currently, Navi 21 and Navi 31 (RDNA 2.0 and RDNA 3.0) targets are supported, while a number of other GPUs are undergoing testing and development.

The basic aim is to allow developers to use AMD hardware without having to maintain an entirely separate codebase. It’s still a work in progress, but it’s a promising tool that could help break NVIDIA’s stranglehold on parts of the GPGPU market.

You Can Use A CRT As An Audio Amplifier Tube

July 11, 2024 by Lewin Day 36 Comments

When we talk about audio amplifier tubes, we’re normally talking about the glass little blobby things you might find in a guitar amplifier. We’re not normally talking about big ol’ color CRTs, but apparently they can do the job too. That’s what [Termadnator] is here to show us.

The CRT in question is a 14″ unit from a common garden variety Philips color TV. [Termadnator] pulled out the TV’s original circuitry, and replaced much of it with his own. He had to whip up a high-voltage power supply with a 555 and a laptop power supply, along with a bunch of fake MOSFETs pressed into service. He also had to build his own Leyden jar capacitor, too. The specifics of converting it to audio operation get a bit messy, but fear not—[Termadnator] explains the idea well, and also supplies a schematic. Perhaps the coolest thing, though, is the crazy color pattern that appears on the display when it’s working as an amp.

Sound output isn’t exactly loud, and it’s a little distorted, too. Still, it’s amusing to see an entire TV instead doing the job of a single amplifier tube. Video after the break.

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Building A Cassette Deck Controller To Save A Locked Out Car Stereo

July 9, 2024 by Lewin Day 26 Comments

Cars have had DRM-like measures for longer than you might think. Go back to the 1990s, and coded cassette decks were a common way to stop thieves being able to use stolen stereos. Sadly, they became useless if you ever lost the code. [Simon] had found a deck in great condition that was locked out, so he set about building his own controller for it.

The build relies on the cassette transport of a car stereo and a VFD display, but everything else was laced together by Simon. It’s a play-only setup, with no record, seeing as its based on an automotive unit. [Simon]’s write up explains how he reverse engineered the transport, figuring out how the motors and position sensors worked to control the playback of a cassette.

[Simon] used an Atmega microcontroller as the brains of the operation, which reads the buttons of the original deck via an ADC pin to save I/O for other tasks. The chip also drives the VFD display for user feedback, and handles auto reverse too. The latter is thanks to the transport’s inbuilt light barriers, which detect the tape’s current status. On the audio side, [Simon] whipped up his own head amplifier to process the signal from the tape head itself.

Fundamentally, it’s a basic build, but it does work. We’ve seen other DIY tape decks before, too. There’s something about this format that simply refuses to die. The fans just won’t let Compact Cassette go down without a fight. Video after the break.

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Dad? Where Did Printed Circuit Boards Come From?

July 5, 2024 by Al Williams 18 Comments

These days, it is hard to imagine electronics without printed circuit boards. They are literally in everything. While making PCBs at home used to be a chore, these days, you design on a computer, click a button, and they show up in the mail. But if you go back far enough, there were no PC boards. Where did they come from? That’s the question posed by [Steven Leibson] who did some investigating into the topic.

There were many false starts at building things like PCBs using wires glued to substrates or conductive inks. However, it wasn’t until World War II that mass production of PC boards became common. In particular, they were the perfect solution for proximity fuzes in artillery shells.

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A small 3D-printed printing press with a print that says THE QUICK BROWN FOX JUMPED OVER THE LAZY BROWN DOG.

Mini 3D-Printed Press Is Sure To Make An Impression

July 4, 2024 by Kristina Panos 9 Comments

Making stamps out of potatoes that have been cut in half is always a fun activity with the kids. But if you’ve got a 3D printer, you could really step up your printing game by building a mini relief printing press.

To create the gear bed/rack, [Kevr102] used a Fusion 360 add-in called GF Gear Generator. At first this was the most finicky part of the process, but then it was time to design the roller gears. However, [Kevr102] got through it with some clever thinking and a little bit of good, old-fashioned eyeballing.

Per [Kevr102], this press is aimed at the younger generation of printers in that the roller mechanism is spring-loaded to avoid pinched fingers. [Kevr102] 3D-printed some of the printing tablets, which is a cool idea. Unfortunately it doesn’t work that well for some styles of text, but most things came out looking great. You could always use a regular linocut linoleum tile, too.

This isn’t the first 3D-printed printing press to grace these pages. Here’s one that works like a giant rubber stamp.