Saving Some Coin With 3D Printed Stencils

One of the extra tools someone might need when working with surface-mount components is a solder paste stencil, which not only simplifies the application of solder paste to a PCB but increases accuracy. These metal stencils can cost an annoying amount of money and take time to get delivered, so this group has developed a method to 3D print them instead.

Starting with a PCB design in one’s tool of choice, the Gerber files can be sent to the online Stenchill tool to generate the stencil. Alternatively, a KiCad plugin exists as well. The tool will output files for a 3D printer from there. An FDM printer is required, with either PLA or PETG filament, and some configuration in the slicer is needed to get the accuracy required for a useful stencil. But once that’s all set up, the printer can output a perfectly usable stencil at a fraction of the cost, and without having to wait days for delivery through the mail.

It’s not all upside, though. Although it might be better than applying solder paste with a syringe on a massive board or doing more than one smaller board by hand, it may not be as good as a metal stencil for extremely small pads. But for those who often find themselves using metal stencils and dealing with the downsides that come with them, this could be a viable alternative, especially when prototyping.

If you have a laser cutter handy, that opens up some additional options for stencil production.

Continue reading “Saving Some Coin With 3D Printed Stencils”

A Raspberry Pi Pico 2 W connected to a speaker

Voice Control Toolkit Comes To A Pico Near You

Voice-controlled appliances are nothing new. What might be new, however, is [Moonshine AI] running it all locally on a Raspberry Pi Pico 2 W!

The voice interface is roughly divided into three parts: voice activity detection, SpellingCNN speech-to-text and a neural text to speech. The speech to text supports up to 50 tokens, and can be re-trained to support any specific words you want. It runs a simple loop: detect voice activity, listen for (command) tokens, process them in C++, use the TTS to reply, and repeat.

Now, to be fair, it is a bit of a squeeze: 3.6 MiB of the available 4 MiB FLASH and 468 KiB SRAM on a stock Pi Pico 2 board. It leaves you with just about enough space to write a small amount of extra software, but it’ll be a challenge to fit anything substantial. Still, fitting three different types of AI model needed to make this possible in such a space is quite impressive.

Industrial GPU Adapted For The Desktop

As technologies change and adapt, we’re often left with seemingly useless junk that has nowhere to go. Certainly anyone still sitting on a pile of floppy disks feels this way sometimes, but odds are anyone who owns a mining ASIC or an NFT can attest to that as well. The trillions of dollars flowing into GPU-based data centers will likely become the next victim of this trend, so if you want to capitalize on the losses of some venture capitalist you’ll want to figure out a way to get GPUs meant for a server into your desktop doing useful work.

Of course, calling these devices GPUs is a bit of a stretch compared to the Radeon and GeForce cards many of us are used to using for gaming. These don’t even have a PCIe slot or video output, after all. But, as [] notes, the VRAM and GPU cores are very real and can still do useful work. An adapter board is able to mate a Tesla V100 SXM2 16 GB GPU to a standard PCIe slot, which solves the first problem, but the major downside from there is that the cooling fan for this unit was literally deafeningly loud. At 82 dB it was about as loud as a lawnmower, which is fine in a server rack but not great in a bedroom. [Oscar] found a way to tamp down the fan speed, making it usable in a home.

Without video output, the utility of these cards mainly comes from adding VRAM and compute for tasks that benefit from parallel computing. Using tensor splitting, [Oscar] is running a local LLM with this card alongside his RTX 4080, providing 32 GB of VRAM on his NixOS system. With his benchmarking tests, the LLM sports impressive stats for a self-hosted model, ranking somewhere around Claude Sonnet 4.6. What’s even more impressive is that this is all done for around £200, and with the rate the various LLM companies are ratcheting up pricing could pay itself back very quickly. If trading off performance for cost is acceptable, though, it’s possible to run local models on much less powerful hardware as well.

V Formation Flying Of Birds Is Explained By A Minimal Wake–Vortex Model

Although it’s commonly suspected that migratory birds fly in a ‘V’ formation due to this saving energy for the birds in the slipstream, understanding the exact aerodynamics behind this and how it affects the way that the birds use their wings to maintain this optimal pattern. After all, unlike airplanes and cars, our feathered avian dinosaur friends need to flap their wings if they want to have any chance of staving off plummeting back to Earth. Recent research by Brown University researchers now have provided a simulated model that answers many questions.

The major question was how this would work in the up- and down-wash zones created in this type of formation, with every bird following the lead bird dealing with the vortices created by the flapping of the wings of the bird before them. These wake vortices are quite complex, and thus required careful modelling to make sense of them.

As described in the paper by [Olivia Pomerenk] et al., the model is based on northern bald ibises, taking into account live-bird measurements for validation of the model. The main effect that can be observed is a reduced flapping amplitude, leading to an 11% energy savings for the birds in the leader’s wake.

The main advantage of having such a model is of course that it provides insight into the kinematic and aerodynamic mechanisms, meaning the ability to model virtual flocks of birds, predict the efficiency of specific in-flight configurations, and apply the lessons to swarms of drones, or whatever else we want to put in the air.

A zoomed out screenshot of a flow chart recipe. It is made of 8 bit ingredient icons with their name and amounts moving through steps to the finished "Vegan Chicken Parmy Feast."

An LLM In The Kitchen

Have you ever been looking up a recipe for something new and been stymied by the directions being a wall of text, especially to find that one detail right when you’re in the middle of making the dish? Recipe Lanes by [bohemian-miser] leverages an LLM to create flow charts to make the process more straightforward.

As someone who has mostly avoided LLM use thus far, I found the examples in the Gallery helped inform what the LLM was expecting for prompts as my first attempts were unsuccessful. Once you know the language expected from the computer, you can get it to generate icons for each ingredient and a flow chart of the steps to cook the food. While it does organize the chart when it is generated, each element can be independently moved across the canvas to put things in a more sensible order, especially as I found it can generate elements with overlapping text.

The 8-bit icon style and button text on the site give it a fun bit of flair that adds to the overall experience. The tool is still in its infancy, but it’s Open Source, so we hope to see it improve over time. If you’d like to see some more interesting kitchen hacks, how about ramen in edible packaging, this rotary phone kitchen timer, or these automated Arduino splash guards.

The Need For Speed: Internet Speed Measurement (or DIY?)

Car enthusiasts want to know how quickly they can make a quarter mile. Weightlifters are forever trying to add one more plate to the bar. Internet denizens have their own favorite number to brag about: the result from a speed test.

The ritual is familiar. Close a few browser tabs, click the big “Go” button, and watch the needle climb. Perhaps you pay for gigabit service and see 940 megabits per second, which produces a satisfied nod. Perhaps you see 299 megabits and begin obsessing over network hardware. But before you get too excited either way, try another test. There is a fair chance it will give you a different answer.

That does not necessarily mean one test is lying. “Internet speed” is not a single physical quantity waiting to be measured. A speed test measures the performance of a particular device, over a particular local connection, through a particular ISP route, to a particular server, at a particular time using a particular test method. Change any of those things and the answer can change too. Continue reading “The Need For Speed: Internet Speed Measurement (or DIY?)”