Make DIY Conductive, Biodegradable String Right In Your Kitchen

March 28, 2025 by Donald Papp 3 Comments

[ombates] shares a step-by-step method for making a conductive bio-string from scratch, no fancy equipment required. She demonstrates using it to create a decorative top with touch-sensitive parts, controlling animations on an RGB LED pendant. To top it off, it’s even biodegradable!

The string is an alginate-based bioplastic that can be made at home and is shaped in a way that it can be woven or knitted. Alginate comes primarily from seaweed, and it gels in the presence of calcium ions. [ombates] relies on this to make a goopy mixture that, once extruded into a calcium chloride bath, forms a thin rubbery length that can be dried into the strings you see here. By adding carbon to the mixture, the resulting string is darkened in color and also conductive.

There’s no details on what the actual resistance of a segment of this string can be expected to measure, but while it might not be suitable to use as wiring it is certainly conductive enough to act as a touch sensor in a manner similar to the banana synthesizer. It would similarly be compatible with a Makey Makey (the original and incredibly popular hardware board for turning household objects into touch sensors.)

What you see here is [ombates]’ wearable demonstration, using the white (non-conductive) string interwoven with dark (conductive) portions connected to an Adafruit Circuit Playground board mounted as an LED pendant, with the conductive parts used as touch sensors.

Alginate is sometimes used to make dental molds and while alginate molds lose their dimensional accuracy as they dry out, for this string that’s not really a concern. If you give it a try, visit our tip line to let us know how it turned out!

Handheld Console Plays Original Pong With Modern E-Waste

March 24, 2025 by Donald Papp 8 Comments

[Simon] wrote in to let us know about DingPong, his handheld portable Pong console. There’s a bit more to it than meets the eye, however. Consider for a moment that back in the 1970s playing Pong required a considerable amount of equipment, not least of which was dedicated electronics and a CRT monitor. What was huge (in more than one way) in the 70s has been shrunk down to handheld, and implemented almost entirely on modern e-waste in the process.

The 1970s would be blown away by a handheld version of Pong, made almost entirely from salvaged components.

DingPong is housed in an old video doorbell unit (hence the name) and the screen is a Sony Video Watchman, a portable TV from 1982 with an amazing 4-inch CRT whose guts [Simon] embeds into the enclosure. Nearly everything in the build is either salvaged, or scrounged from the junk bin. Components are in close-enough values, and power comes from nameless lithium-ion batteries that are past their prime but still good enough to provide about an hour of runtime. The paddle controllers? Two pots (again, of not-quite-the-right values) sticking out the sides of the unit, one for each player.

At the heart of DingPong one will not find any flavor of Arduino, Raspberry Pi, or ESP32. Rather, it’s built around an AY-3-8500 “Ball & paddle” (aka ‘Pong’) integrated circuit from 1977, which means DingPong plays the real thing!

We have seen Pong played on a Sony Watchman before, and we’ve also seen a vintage Pong console brought back to life, but we’re pretty sure this is the first time we’ve seen a Sony Watchman running Pong off a chip straight from the 70s. Watch it in action in the video (in German), embedded below.

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Wearable Computing Goes Woven, Wireless, And Washable

March 24, 2025 by Donald Papp 5 Comments

Sometimes we come across a wild idea that really tries to re-imagine things, and re-conceiving wearable computing as a distributed system of “fiber computers” embedded into textiles is definitely that. The research paper presents fully-functional fiber computers and sensors that are washable, weave-able, wireless, and resist both stretching and bending.

The research paper with all the details is behind a paywall at this time, but we’ll summarize the important parts that are likely to get a hacker’s mind working.

Each fiber strand (like the one shown here) is a self-contained system. Multiple fibers can communicate with one another wirelessly to create a network that, when integrated into garments, performs tasks like health and activity monitoring while using very little power. And what’s really interesting about these fibers is their profound lack of anything truly exotic when it comes to their worky bits.

The inner components of a fiber computer are pretty recognizable: each contains a surface-mount microcontroller, LEDs, BLE (Bluetooth Low Energy) radio, light sensor, temperature sensor, accelerometer, and photoplethysmography (PPG) sensor for measuring blood volume changes through skin. Power is supplied by a separate segment containing a tiny cylindrical lithium-polymer battery, with a simple plug connector. It’s a tiny battery, but the system is so low-power that it still provides hours of operation.

If there’s a secret sauce, it’s in the fabrication. The first step is stretching a system into a long, thin circuit. Each component is nested onto a small piece of flex PCB that acts a little like a breakout board, and that flex PCB gets rolled around each component to make as tiny a package as possible. These little payloads are connected to one another by thin wires, evenly spaced to form a long circuit. That circuit gets (carefully!) sealed into a thermoformed soft polymer and given an overbraid, creating a fiber that has a few lumps here and there but is nevertheless remarkably thin and durable. The result can be woven into fabrics, worn, washed, bent, and in general treated like a piece of clothing.

Closeups of components that make up a single strand of “fiber computer”.

Multiple fibers are well-suited to being woven into clothing in a distributed way, such as one for each limb. Each fiber is self-contained but communicates with its neighbors using a BLE mesh, or transmitting data optically via embedded LEDs and light sensors. Right now, such a distributed system has been shown to be able to perform health monitoring and accurately classify different physical activities.

We’ve seen sensors directly on skin and transmitting power over skin, but this is a clever fusion of conventional parts and unconventional design — wearable computing that’s not just actually wearable and unobtrusive, but durable and even washable.

Cloudflare’s AI Labyrinth Wants Bad Bots To Get Endlessly Lost

March 24, 2025 by Donald Papp 37 Comments

Cloudflare has gotten more active in its efforts to identify and block unauthorized bots and AI crawlers that don’t respect boundaries. Their solution? AI Labyrinth, which uses generative AI to efficiently create a diverse maze of data as a defensive measure.

This is an evolution of efforts to thwart bots and AI scrapers that don’t respect things like “no crawl” directives, which accounts for an ever-growing amount of traffic. Last year we saw Cloudflare step up their game in identifying and blocking such activity, but the whole thing is akin to an arms race. Those intent on hoovering up all the data they can are constantly shifting tactics in response to mitigations, and simply identifying bad actors with honeypots and blocking them doesn’t really do the job any more. In fact, blocking requests mainly just alerts the baddies to the fact they’ve been identified.

Instead of blocking requests, Cloudflare goes in the other direction and creates an all-you-can-eat sprawl of linked AI-generated content, luring crawlers into wasting their time and resources as they happily process an endless buffet of diverse facts unrelated to the site being crawled, all while Cloudflare learns as much about them as possible.

That’s an important point: the content generated by the Labyrinth might be pointless and irrelevant, but it isn’t nonsense. After all, the content generated by the Labyrinth can plausibly end up in training data, and fraudulent data would essentially be increasing the amount of misinformation online as a side effect. For that reason, the human-looking data making up the Labyrinth isn’t wrong, it’s just useless.

It’s certainly a clever method of dealing with crawlers, but the way things are going it’ll probably be rendered obsolete sooner rather than later, as the next move in the arms race gets made.

Reviving A Maplin 4600 DIY Synthesizer From The 1970s

March 19, 2025 by Donald Papp 16 Comments

A piece of musical history is the Maplin 4600, a DIY electronic music synthesizer from the 1970s. The design was published in an Australian electronics magazine and sold as a DIY kit, and [LOOK MUM NO COMPUTER] got his hands on an original Maplin 4600 that he refurbishes and puts through its paces.

Inserting conductive pegs is how the operator connects different inputs and outputs.

The Maplin 4600 is a (mostly) analog device with a slightly intimidating-looking layout. It features multiple oscillators, mixers, envelope generators, filters, and a complex-looking patch bay on the right hand side that is reminiscent of a breadboard. By inserting conductive pins, one can make connections between various inputs and outputs.

Internally the different features and circuits are mostly unconnected from one another by default, so the patch board is how the instrument is “programmed” and the connections made can be quite complex. The 4600 is one of a few synthesizer designs by [Trevor Marshall], who has some additional details about on his website.

The video (embedded below) is a complete walk-through of the unit, including its history, quirks, and design features. If you’d like to skip directly to a hands-on demonstrating how it works, that begins around the 10:15 mark.

Synthesizers have a rich DIY history and it’s fascinating to see an in-depth look at this one. And hey, if you like your synths complex and intimidating, do yourself a favor and check out the Starship One.

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Make Fancy Resin Printer 3D Models FDM-Friendly

March 19, 2025 by Donald Papp 17 Comments

Do you like high-detail 3D models intended for resin printing, but wish you could more easily print them on a filament-based FDM printer? Good news, because [Jacob] of Painted4Combat shared a tool he created to make 3D models meant for resin printers — the kind popular with tabletop gamers — easier to port to FDM. It comes in the form of a Blender add-on called Resin2FDM. Intrigued, but wary of your own lack of experience with Blender? No problem, because he also made a video that walks you through the whole thing step-by-step.

Resin2FDM separates the model from the support structure, then converts the support structure to be FDM-friendly.

3D models intended for resin printing aren’t actually any different, format-wise, from models intended for FDM printers. The differences all come down to the features of the model and how well the printer can execute them. Resin printing is very different from FDM, so printing a model on the “wrong” type of printer will often have disappointing results. Let’s look at why that is, to better understand what makes [Jacob]’s tool so useful.

Rafts and a forest of thin tree-like supports are common in resin printing. In the tabletop gaming scene, many models come pre-supported for convenience. A fair bit of work goes into optimizing the orientation of everything for best printed results, but the benefits don’t carry directly over to FDM.

For one thing, supports for resin prints are usually too small for an FDM printer to properly execute — they tend to be very thin and very tall, which is probably the least favorable shape for FDM printing. In addition, contact points where each support tapers down to a small point that connects to the model are especially troublesome; FDM slicer software will often simply consider those features too small to bother trying to print. Supports that work on a resin printer tend to be too small or too weak to be effective on FDM, even with a 0.2 mm nozzle.

To solve this, [Jacob]’s tool allows one to separate the model itself from the support structure. Once that is done, the tool further allows one to tweak the nest of supports, thickening them up just enough to successfully print on an FDM printer, while leaving the main model unchanged. The result is a support structure that prints well via FDM, allowing the model itself to come out nicely, with a minimum of alterations to the original.

Resin2FDM is available in two versions, the Lite version is free and an advanced version with more features is available to [Jacob]’s Patreon subscribers. The video (embedded below) covers everything from installation to use, and includes some general tips for best results. Check it out if you’re interested in how [Jacob] solved this problem, and keep it in mind for the next time you run across a pre-supported model intended for resin printing that you wish you could print with FDM.

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How To Use LLMs For Programming Tasks

March 11, 2025 by Donald Papp 60 Comments

[Simon Willison] has put together a list of how, exactly, one goes about using a large language models (LLM) to help write code. If you have wondered just what the workflow and techniques look like, give it a read. It’s full of examples, strategies, and useful tips for effectively using AI assistants like ChatGPT, Claude, and others to do useful programming work.

It’s a very practical document, with [Simon] emphasizing realistic expectations and the importance of managing context (both in terms of giving the LLM direction, as well as the model’s context in terms of being mindful of how much the LLM can fit in its ‘head’ at once.) It is useful to picture an LLM as a capable and obedient but over-confident programming intern or assistant, albeit one that never gets bored or annoyed. Useful work can be done, but testing is crucial and human oversight simply cannot be automated away.

Even if one has no interest in using LLMs to help in writing production code, there’s still a lot of useful work they can do to speed up the process of software development in general, especially when learning. They can help research options, interactively explore unfamiliar codebases, or prototype ideas quickly. [Simon] provides useful strategies for all these, and more.

If you have wondered how exactly glorified chatbots can meaningfully help with software development, [Simon]’s writeup hopefully gives you some new ideas. And if this is is all leaving you curious about how exactly LLMs work, in the time it takes to enjoy a warm coffee you can learn how they do what they do, no math required.