Build A Strandbeest Replica Of Your Very Own

December 3, 2023 by 1 Comment

[Theo Jansen] is famous for his giant walking Strandbeest creations. They’re elegant, impressive, and powered by nature, and their walking mechanism is a thing of beauty. If you’ve ever wanted to build your own, [Antonio Garcia] has just the guide to get you started on the smaller scale.

Unlike so many other builds today, this one features some good old fashioned craft techniques. The build uses popsicle sticks for the legs, what appear to be toothpicks for the joints, and a cardboard box for the main body. A small brushed DC motor is used for propulsion to keep things easy, which runs off a few AA batteries. It’s a gearmotor, which gives it plenty of torque to propel the walking mechanism without undue strain.

It may not be powered by nature, and it may not be taller than most humans, but it’s still got an appealing gait and it still inspires us with its design. If you want to learn more, go ahead and take a gander at [Theo Jansen’s] own designs and see what you can pick up. Video after the break.

Continue reading “Build A Strandbeest Replica Of Your Very Own” →

Simple Chemistry To Metallize And Etch Silicon Chips

December 3, 2023 by 5 Comments

We’ve been eagerly following [ProjectsInFlight]’s stepwise journey toward DIY semiconductors, including all the ups and downs, false leads, and tedious optimizations needed to make it possible for the average hacker to make chips with readily available tools and materials.

Next up is metallization, and spoiler alert: it wasn’t easy. In a real fab, metal layers are added to chips using some form of deposition or sputtering method, each of which needs some expensive vacuum equipment. [ProjectsInFlight] wanted a more approachable way to lay down thin films of metal, so he turned to an old friend: the silver mirror reaction. You may have seen this demonstrated in high school chemistry; a preparation of Tollen’s reagent, a mix of sodium hydroxide, ammonia, and silver nitrate, is mixed with glucose in a glass vessel. The glucose reduces the reagent, leaving the metallic silver to precipitate on the inside of the glass, which creates a beautiful silvered effect.

Despite some issues, the silvering method worked well enough on chips to proceed on, albeit carefully, since the layer is easily scratched off. [ProjectsInFlight]’s next step was to find an etchant for silver, a tall order for a noble metal. He explored piranha solutions, which are acids spiked with peroxide, and eventually settled on plain old white vinegar with a dash of 12% peroxide. Despite that success, the silver layer was having trouble sticking to the chip, much preferring to stay with the photoresist when the protective film was removed.

The solution was to replace the photoresist’s protective film with Teflon thread-sealing tape. That allowed the whole process from plating to etching to work, resulting in conductive traces with pretty fine resolution. Sure they’re a bit delicate, but that’s something to address another day. He’s come a long way from his DIY tube furnace used to put down oxide layers, and suffering through the search for oxide etchants and exploring photolithography methods. It’s been a fun ride so far, and we’re eager to see what’s next.

Continue reading “Simple Chemistry To Metallize And Etch Silicon Chips” →

Adding Cellular Connectivity To The Hackaday Supercon Badge

December 2, 2023 by 1 Comment

Did you manage to make it down to Hackaday Supercon 2023? Maybe you did, and maybe you had a great time hacking away on the badge. [Dan] and ex-Hackaday alumnus [Mike Szczys] certainly did, with the guys from Golioth adding cellular connectivity to the hardware and developing a community art project.

The badge was hooked up over I2C to a Golioth Aludel Mini, which is a prototyping platform featuring a Sparkfun nRF9160 cellular modem. A custom Micropython implementation was compiled for the badge so that the badge could act as an I2C peripheral to be queried by the Aludel Mini. The sketch app on the badge was tweaked to allow the small pictures it created to be be uploaded to a cloud site called Badgecase, programmed in Rust. Amusingly, it turns out the sketch app uses a rectangular workspace, though you only see a circular section of it on the Supercon badge’s awesomely round display.

Much of the hack is happening off-board from the badge itself, but it’s a neat piece of work that shows how easy cellular connectivity is to implement these days. We’ve seen some other great feats with the Vectorscope badge, and it looked great if you happened to 3D print a case for it, too. Video after the break.

Continue reading “Adding Cellular Connectivity To The Hackaday Supercon Badge” →

Honey, I Ate The Camera

December 2, 2023 by 17 Comments

We like cameras here at Hackaday. We like them a lot. But until now that liking has never extended to liking their taste. A build from [Dmitri Tcherbadji] could change all that though, and he’s created a working Fuji Instax Square camera made from gingerbread.

To look at, it’s a straightforward box camera, albeit one made from sheets of gingerbread stuck together with what looks like icing. The film rests in an off-the-shelf development unit but the rest is edible, including unexpectedly the lens which is made of sugar glass. The photos it returns are definitely somewhat cloudy, but that it works at all is a significant feat.

While it’s an unconventional choice it’s clear that gingerbread, or at least a baked material similar to it, could become a useful tool in a maker’s arsenal. In this case it’s light-proof, but were instantly curious about how well a moulded piece of dough might hold its shape when baked. He reports the gingerbread expanding in the oven, however we’re guessing that tuning the quantity of raising agent could help.

Home-made cameras have featured here many times, but Instax seems to pop up most often as a hacked in replacement for obsolete Polaroid packs.

Mozilla Lets Folks Turn AI LLMs Into Single-File Executables

December 2, 2023 by 20 Comments

LLMs (Large Language Models) for local use are usually distributed as a set of weights in a multi-gigabyte file. These cannot be directly used on their own, which generally makes them harder to distribute and run compared to other software. A given model can also have undergone changes and tweaks, leading to different results if different versions are used.

To help with that, Mozilla’s innovation group have released llamafile, an open source method of turning a set of weights into a single binary that runs on six different OSes (macOS, Windows, Linux, FreeBSD, OpenBSD, and NetBSD) without needing to be installed. This makes it dramatically easier to distribute and run LLMs, as well as ensuring that a particular version of LLM remains consistent and reproducible, forever.

This wouldn’t be possible without the work of [Justine Tunney], creator of Cosmopolitan, a build-once-run-anywhere framework. The other main part is llama.cpp, and we’ve covered why it is such a big deal when it comes to running self-hosted LLMs.

There are some sample binaries available using the Mistral-7B, WizardCoder-Python-13B, and LLaVA 1.5 LLMs. Just keep in mind that if you’re on a Windows platform, only the LLaVA 1.5 will run, because it’s the only one that squeaks under the 4 GB limit on executable files that Windows has. If you run into issues, check out the gotchas list for troubleshooting tips.

Build Yourself A Screw Propelled Robot To Tackle The Dirt

December 2, 2023 by 11 Comments

Wheels and tracks are common choices for robot propulsion, but they’re not the only game in town. You can do some nifty things with long extruded screws , and they work pretty well in soft terrain. [gokux] set about building a small robot using this propulsion method using 3D printed parts.

The build uses a Seeed Studio XIAO ESP32S3 as the brains of the operation. This provides wireless connectivity for remote control, as well as a way to get a low-latency video feed out of the robot from the OV2640 camera. The ESP32 controls a pair of brushed DC gearmotors via a DRV8833 motor driver. Each drives one of the two screws on the robot. By driving the two screws separately, the robot has simple skid steering. Two 18650 lithium-ion cells provide power for the robot, and are charged via a TP4056 battery charger module.

If you want to build a small robot that can handle soft terrain well, screw drives could be just the solution you’re looking for. They’re usually a bit slow, though, especially for human-scale conveyances, so don’t write off wheels or tracks if you don’t have to. And, of course, when your build is done, don’t forget to put it online and tell us all about it!

Update On The BLUFFS Bluetooth Vulnerability

December 2, 2023 by 14 Comments

As we first reported in yesterday’s weekly security post, researchers at EURECOM have revealed the details (PDF, references) of a new man-in-the-middle (MITM) attack on Bluetooth 4.2 through 5.4, which has been assigned CVE-2023-24023. Like preceding CVEs, it concerns the session authentication between Bluetooth devices, where the attacker uses spoofed paired or bonded devices to force the use of a much shorter encryption key length.

The name of this newly discovered vulnerability is BLUFFS (Bluetooth Forward and Future Secrecy), where forward and future secrecy are important terms that refer to the protection of secure sessions against compromise in the past (forward, FoS) and future (FuS). The CVE presentation notes that the Bluetooth specification does not cover either FuS or FoS. In total two new architectural vulnerabilities were discovered, both of which attack the security key.

The Bluetooth SIG has released a statement regarding this attack method. Although serious, it would seem that the core issue is that some implementations allow for encryption key lengths below 7 octets:

Continue reading “Update On The BLUFFS Bluetooth Vulnerability” →