Author: Bryan Cockfield

1850 Articles

Custom Beach Robot Handles The Hard Work

July 30, 2026 by 4 Comments

A day at the beach can involve hauling a surprising amount of gear, from coolers, towels, blankets, chairs, and umbrellas, and if children are involved the amount of beach stuff needed seems to go nonlinear very quickly. Some turn to beach carts with large, low-pressure pneumatic tires, but even that seemed like too much work for [John] who built this remote controlled cart for his summertime needs.

The cart is based around an old cargo rack from an e-bike. To mount all of the robotic components, a sheet of plywood was cut and attached to the underside. Two motors are used to drive the rear wheels independently, allowing for differential steering rather than adding the complexity of a steering system. Some safety features are built in to this design as well, including lights for night driving, a start button controlling a relay for the motors and electronics, and a time-of-flight sensor to stop the robot if it encounters an obstacle.

The ESP32 at the center of the build ties all of the electronics together, and a smartphone app lets the user remotely pilot the rover. It’s not autonomous (yet) but a fair alternative to dragging all of one’s beach gear through the sand without any assistance. You could also minimize your excursions through the sand by timing your visits at high tide, but [John] is out on the Great Lakes so this may be of marginal utility here.

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Wrangling Datacenter GPUs Into A Desktop

July 30, 2026 by 17 Comments

As we’ve seen many times before, there’s usually some way wrangle a bit more life out of what would otherwise be considered old and obsolete technology. Perhaps one thing that has been passed over by the masses a bit to early is older datacenter GPUs, which is understandable in one sense because of the rate NVIDIA is pumping out new ones, but these cards have plenty of useful life left in them for the average person, as [Andrew] demonstrates.

The cards [Andrew] is using are Tesla V100s of 2017 vintage. Despite being older hardware they have high-speed memory which allows them to run modern LLMs locally, competitively with online models. In this test, Gemma 4 26B and Qwen3 35B are run, with Gemma being a bit faster because it fits entirely in GPU memory and Qwen3 being a bit more capable but more hungry for resources. [Andrew] built a PCI card that can host two V100s, allowing these larger models to fit completely in memory.

Even though these don’t perform at the same level as the latest top-tier online models, they’re surprisingly capable and also have the benefit of running completely locally. This might be concerning for those looking at the global economy being propped up by companies that essentially have no moat for motivated users, especially as more and more datacenter hardware becomes available on the secondhand market. While this build by [Andrew] goes into detail on getting the software stack up and running, we recently featured another build using the same GPUs that focuses a bit more on hardware for those looking to get started with local hosting.

Use Your Head While Trimming Trees

July 29, 2026 by 38 Comments

[Attoparsec] occasionally rides a bicycle for transportation, but with the major downside of doing this in North America, a place where bicycle infrastructure is generally neglected. From snow removal, maintenance, separation from cars, or even existing in the first place, the places bicyclists use are generally last to be cared for. One of these deficiencies is landscaping maintenance, with plant growth routinely extending into travel ways. Rather than continue to get hit in the face by tree branches, [Attoparsec] took matters into his own hands, or in this case, head.

Since he’s riding down the bike path anyway, the original thought was to add a trimmer to the front of the bicycle. This has a notable downside of being dangerous to others, so instead he added a string trimmer to his helmet. The electric trimmer was scavenged from an old handheld landscaping tool, with a 3D printed mount designed in CAD to cleanly mount to his bicycle helmet. It’s wired to a control on the handlebar, so when a branch is coming up it can be activated by hand and then pruned without much thought other than properly aiming one’s head.

By most measures this eccentric contraption seems to work quite well. There’s not enough torque to affect the rider’s head in any negative way, the strings are long enough to reach far enough to trim the leaves and branches before they can impact the rider’s face, and it’s safe for other users of the bike path. [Attoparsec] calls this “guerrilla urban landscaping”, a bit different from other forms of guerrilla gardening we have seen before.

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Regain Some Trust In Unknown USB Drives

July 27, 2026 by 23 Comments

For how useful USB thumb drives are for quickly toting around and copying files from one computer to another, they can be a bit of a security headache. Programs can be loaded on them with all kinds of malware; they can be obscured in some ways that are difficult to detect, and they can be set up to execute certain programs when they’re plugged in. The general wisdom is to simply avoid untrusted USB devices completely, but that sort of abstinence-only policy rarely works in the real world. If, for some reason, an untrusted USB device absolutely needs to be used, many of these security issues can be mitigated with this tool.

Built by [Novamostra], the device is simple on the surface: it’s a Raspberry Pi Pico mated to a 2-in-1 USB splitter cable. But with the USB Neutralizer software they have written loaded onto the Pico, it automatically destroys the ability of any connected USB thumb drive to load files. The program works by deleting the first and last 34 Logical Block Addressing (LBA) sectors on the drive immediately when it’s plugged in, without doing anything else. This effectively corrupts the drive bad enough to prevent malicious software in the partitions from doing anything, allowing the user to (relatively) safely put the USB drive into their computer and format it for re-use. The code for this tool is also open-source and reviewable on the project’s GitHub page.

Of course, this isn’t a perfect security solution for all USB attacks. It doesn’t erase or replace the firmware on the drive itself, and although firmware-level attacks are rare they’re not out of the question for all users, all the time. It also won’t prevent a malicious physical attack like this high-voltage one, and it may also not stop hidden or obscured partitions or devices programmed for storage and some other nefarious purpose simultaneously, like a USB HID. But still, this solves a great many of the problems associated with getting new drives from semi-untrustworthy sources, like retailers or friends whose computer skills we don’t fully trust.

Neighborhood Bulletin Boards, Circa 1982

July 27, 2026 by 8 Comments

When the Internet first started gaining mainstream popularity in the late 90s, many optimists claimed that it would bring people together by reducing barriers to communication. That ideal hasn’t exactly come to pass yet, as anyone who has been on the Nextdoor neighborhood social network can likely attest to. Before social media, neighbors weren’t completely in the dark about their local communities, though. Besides word-of-mouth communication, there were also local access channels on cable TV, which had none of the downsides of modern social media. And [Hans] is bringing this style channel back.

[Hans]’s project is called CABLE 82, a bulletin board channel that matches the style of these channels from the 1980s. There’s better technology available for these types of systems now, though, so instead of relying on something like a character generator he’s using a Raspberry Pi running custom software to produce the video feed. The Pi hosts a web server so the 4:3 video feed can be reserved for the bulletin board display, but users who have older Pis with the yellow composite video output can skip using something like an HDMI to RF converter on their period-appropriate CRT displays. The software also adds sound functionality, as these channels always had some sort of elevator music playing while they were scrolling through local community news.

For those looking to recreate some of the nostalgia of 1980s community and technology, [Hans] has made this project open source, with all of the files on a GitHub page. Part of the reason [Hans] got interested in building something like this is that he had been trying to source a CRT television for retro gaming, and wanted to reproduce more of that era than just a few video games. A channel like this would be a great addition to a complete cable TV recreation build like this one, which even includes a preview channel of everything playing.

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Exploring Hidden JPEG Features

July 24, 2026 by 25 Comments

The lossy compression algorithm used by JPEG was useful for those on the early Internet not only because it enabled pictures to be shared easier, but because it allows a low-resolution version of the image to load first. This meant that users could make out the gist of an image before it finished downloading. This was a great feature for those on slow connections, but it hides some other capabilities of this image format as well.

Rather than effectively splitting up the image into chunks, each with successive amounts of detail, [maurycyz]’s project shows that this can be exploited to load more than one picture. The first is loaded into this lower-resolution area, with a second unrelated picture showing up once the higher-resolution information is available. Essentially this makes a one-way .gif of sorts. Though this method is only capable of loading about nine frames, which is not enough for much animation. Further limiting things is that there’s no way to encode timing data, so on fast computers with fast connections the animation could load faster than a user could see.

Still, it’s an interesting quirk of this older image standard, one which still is in widespread use today. And it’s also true that it’s hard to say in what ways various technologies will be used in the future. JPEG images have also been the subject of some artistic projects that might not have been possible without the JPEG standard itself, and even as other formats have tried to supplant it, it still maintains its firm grip on the images on the Internet. More JPEG, please!

Saving Some Coin With 3D Printed Stencils

July 23, 2026 by 18 Comments

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.

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