Messing With A Cassette Player Never Sounded So Good

April 24, 2023 by Donald Papp 8 Comments

Cassette players and tapes are fertile hacking ground. One reason is that their electromechanical and analog nature provides easy ways to fiddle with their operation. For example, slow down the motor and the playback speed changes accordingly. As long as the head is moving across the tape, sound will be produced. The hacking opportunities are nicely demonstrated by [Lara Grant]’s cassette player mod project.

The device piggybacks onto a battery-powered audio cassette player and provides a variety of ways to fiddle with the output, including adjustable echo and delay, and speed control. At the heart of the delay and echo functionality is the PT2399, a part from the late 90s capable of some pretty impressive audio effects (as long as a supporting network of resistors and capacitors are in place, anyway.)

[Lara] provides a schematic for the PT2399’s interface to the cassette player’s output, which is handy should anyone want to try a similar modification. Speed of playback is controlled by adjusting the cassette player’s motor with PWM. Volume control swaps a photocell in place of a rotary volume potentiometer, and additional audio jacks provide flexibility for mixing and matching input and output with other equipment.

You can see it in action in the video embedded below. Intrigued, and want a few more examples of modified tape players? How about a strange sort of cassette synth, or this unique take on a mellotron that uses a whopping 14 modified tape players under the hood? And really out there is the Magnetotron, which consists of a large rotating cylinder with tape loops stuck to it — the magnetic read head is mounted on a wand which the user manually moves across the tapes to create sounds.

Tape players are accessible, hackable things, so remember to drop us a line if you make something neat!

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Chatting With Local AI Moves Directly In-Browser, Thanks To Web LLM

April 24, 2023 by Donald Papp 7 Comments

Large Language Models (LLM) are at the heart of natural-language AI tools like ChatGPT, and Web LLM shows it is now possible to run an LLM directly in a browser. Just to be clear, this is not a browser front end talking via API to some server-side application. This is a client-side LLM running entirely in the browser.

The ability to run an LLM (natural language AI) directly in-browser means more ways to implement local AI while enjoying GPU acceleration via WebGPU.

Running an AI system like an LLM locally usually leverages the computational abilities of a graphics card (GPU) to accelerate performance. This is true when running an image-generating AI system like Stable Diffusion, and it’s also true when implementing a local copy of an LLM like Vicuna (which happens to be the model implemented by Web LLM.) The thing that made Web LLM possible is WebGPU, whose release we covered just last month.

WebGPU provides a way for an in-browser application to talk to a local GPU directly, and it sure didn’t take long for someone to get the idea of using that to get a local LLM to run entirely within the browser, complete with GPU acceleration. This approach isn’t just limited to language models, either. The same method has been applied to successfully create Web Stable Diffusion as well.

It’s a fascinating (and fast) development that opens up new possibilities and, hopefully, gives people some new ideas. Check out Web LLM’s GitHub repository for a closer look, as well as access to an online demo.

3D Scanning A Room With A Steam Deck And A Kinect

April 24, 2023 by Donald Papp 2 Comments

It may not be obvious, but Valve’s Steam Deck is capable of being more than just a games console. Demonstrating this is [Parker Reed]’s experiment in 3D scanning his kitchen with a Kinect and Steam Deck combo, and viewing the resulting mesh on the Steam Deck.

The two pieces of hardware end up needing a lot of adapters and cables.

[Parker] runs the RTAB-Map software package on his Steam Deck, which captures a point cloud and color images while he pans the Kinect around. After that, the Kinect’s job is done and he can convert the data to a mesh textured with the color images. RTAB-Map is typically used in robotic applications, but we’ve seen it power completely self-contained DIY 3D scanners.

While logically straightforward, the process does require some finessing and fiddling to get it up and running. Reliability is a bit iffy thanks to the mess of cables and adapters required to get everything hooked up, but it does work. [Parker] shows off the whole touchy process, but you can skip a little past the five minute mark if you just want to see the scanning in action.

The Steam Deck has actual computer chops beneath its games console presentation, and we’ve seen a Steam Deck appear as a USB printer that saves received print jobs as PDFs, and one has even made an appearance in radio signal direction finding.

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Wolfram Alpha With ChatGPT Looks Like A Killer Combo

April 17, 2023 by Donald Papp 32 Comments

Ever looked at Wolfram Alpha and the development of Wolfram Language and thought that perhaps Stephen Wolfram was a bit ahead of his time? Well, maybe the times have finally caught up because Wolfram plus ChatGPT looks like an amazing combo. That link goes to a long blog post from Stephen Wolfram that showcases exactly how and why the two make such a wonderful match, with loads of examples. (If you’d prefer a video discussion, one is embedded below the page break.)

OpenAI’s ChatGPT is a large language model (LLM) neural network, or more conventionally, an AI system capable of conversing in natural language. Thanks to a recently announced plugin system, ChatGPT can now interact with remote APIs and therefore use external resources.

ChatGPT’s natural language processing ability enables some pretty impressive interactions with Wolfram, enabling the kind of exchange you see here (click to enlarge.)

This is meaningful because LLMs are very good at processing natural language and generating plausible-sounding output, but whether or not the output is factually correct can be another matter. It’s not so much that ChatGPT is especially prone to confabulation, it’s more that the nature of an LLM neural network makes it difficult to ask “why exactly did you come up with your answer, and not something else?” In addition, asking ChatGPT to do things like perform nontrivial calculations is a bit of a square peg and round hole situation.

So how does the Wolfram plugin change that? When asked to produce data or perform computations, ChatGPT can now hand it off to Wolfram Alpha instead of attempting to generate the answer by itself. Both sides use their strengths in this arrangement. First, ChatGPT interprets the user’s question and formulates it as a query, which is then sent to Wolfram Alpha for computation, and ChatGPT structures its response based on what it got back. In short, ChatGPT can now ask for help to get data or perform a computation, and it can show the receipts when it does.

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3D-Printable Foaming Nozzle Shows How They Work

April 16, 2023 by Donald Papp 8 Comments

[Jack]’s design for a 3D-printable foaming nozzle works by mixing air with a fluid like liquid soap or hand sanitizer. This mixture gets forced through what looks like layers of fine-mesh sieve and eventually out the end by squeezing the bottle. The nozzle has no moving parts but does have an interesting structure to make this possible.

The fine meshes are formed by multiple layers of bridged filament.

Creating a foam with liquid soap requires roughly one part soap to nine parts air. The idea is that the resulting foam makes more efficient use of the liquid soap compared to dispensing an un-lathered goop directly onto one’s hands.

The really neat part is that the fine mesh structure inside the nozzle is created by having the printer stretch multiple layers of filament across the open span on the inside of the model. This is a technique similar to that used for creating bristles on 3D-printed brushes.

While this sort of thing may require a bit of expert tweaking to get the best results, it really showcases the way the fundamentals of how filament printers work. Once one knows the process, it can be exploited to get results that would be impossible elsewhere. Here are a few more examples of that: printing only a wall’s infill to allow airflow, manipulating “vase mode” to create volumes with structural ribs, and embedding a fine fabric mesh (like tulle) as either a fan filter or wearable and flexible armor. Everything’s got edge cases, and clever people can do some pretty neat things with them (when access isn’t restricted, that is.)

Need To Pick Objects Out Of Images? Segment Anything Does Exactly That

April 14, 2023 by Donald Papp 7 Comments

Segment Anything, recently released by Facebook Research, does something that most people who have dabbled in computer vision have found daunting: reliably figure out which pixels in an image belong to an object. Making that easier is the goal of the Segment Anything Model (SAM), just released under the Apache 2.0 license.

The online demo has a bank of examples, but also works with uploaded images.

The results look fantastic, and there’s an interactive demo available where you can play with the different ways SAM works. One can pick out objects by pointing and clicking on an image, or images can be automatically segmented. It’s frankly very impressive to see SAM make masking out the different objects in an image look so effortless. What makes this possible is machine learning, and part of that is the fact that the model behind the system has been trained on a huge dataset of high-quality images and masks, making it very effective at what it does.

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Tree Supports Are Pretty, So Why Not Make Them Part Of The Print?

April 10, 2023 by Donald Papp 5 Comments

Here’s an idea that [Nephlonor] shared a couple years ago, but is worth keeping in mind because one never knows when it might come in handy. He 3D printed a marble run track and kept the generated tree supports. As you can see in the image above, the track resembles a roller-coaster and the tree supports function as an automatically-generated scaffolding for the whole thing. Clever!

As mentioned, these results are from a couple of years ago; so this idea should work even better nowadays. Tree supports have come a long way since then, and are available in more slicers than just Cura.

Tree supports without an interface layer is easy mode for “generate me some weird-looking scaffolding”

If you’re going to do this, we suggest reducing or eliminating the support interface and distance, which is the spacing between the supports and the rest of the model. The interface makes supports easier to remove, but if one is intending to leave it attached, it makes more sense to have a solid connection.

And while we’re on the topic of misusing supports, we’d like to leave you with one more trick to keep in mind. [Angus] of Maker’s Muse tucked a great idea into one of his videos: print just the support structure, and use it as a stand for oddly-shaped objects. Just set the object itself to zero walls and zero infill, and the printer will generate (and print) only the support structure. Choose an attractive angle, and presto! A display stand that fits the object like a glove.

You can watch a brief video of the marble run embedded below. Again, tree supports both look better and are available in more slicers nowadays. Have you tried this? If so we’d love to hear about it, so let us know in the comments!

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