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Showing posts from July, 2024

A Trip Down Electronic Toy Memory Lane

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Like many of us, [MIKROWAVE1] had a lot of electronic toys growing up. In a video you can watch below, he asks the question: “ Did electronic toys influence your path? ” Certainly, for us, the answer was yes. The CB “base station” looked familiar although ours was marked “General Electric.” Some of us certainly had things similar to the 150-in-one kit and versions of the REMCO broadcast system . There were many versions of crystal radio kits, although a kit for that always seemed a little like cheating. Shortwave radios were fun in those days, too. We miss the days when you could find interesting stations on shortwave. We were also happy to see the P-box kits . If you weren’t interested in radio, there were also digital logic kits including a “computer” that was really a giant multi-pole switch that could create logic gates. It made us wonder what toys are launching the next generation of engineers. We are not convinced that video games, Tik Tok, and ChatGPT are going to serve th

VHF/UHF Antennas, the Bad, the Ugly, and the Even Worse

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When you buy a cheap ham radio handy-talkie, you usually get a little “rubber ducky” antenna with it. You can also buy many replacement ones that are at least longer. But how good are they? [Learnelectronics] wanted to know, too, so he broke out his NanoVNA and found out that they were all bad , although some were worse than others. You can see the results in the — sometimes fuzzy — video below. Of course, bad is in the eye of the beholder and you probably suspected that most of them weren’t super great, but they do seem especially bad. So much so, that, at first, he suspected he was doing something wrong. The SWR was high all across the bands the antennas targeted. It won’t come as a surprise to find that making an antenna work at 2 meters and 70 centimeters probably isn’t that easy. In addition, it is hard to imagine the little stubby antenna the size of your thumb could work well no matter what. Still, you’d think at least the longer antennas would be a little better. Hams have

Responsive LCD Backlights With A Little Lateral Thinking

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LCD televisions are a technological miracle, but if they have an annoying side it’s that some of them are a bit lacklustre when it comes to displaying black. [Mousa] has a solution, involving a small LCD and a bit of lateral thinking . These screens work by the LCD panel being placed in front of a bright backlight, and only letting light through at bright parts of the picture. Since LCD isn’t a perfect attenuator, some of the light can make its way through, resulting in those less than perfect blacks. More recent screens replace the bright white backlight with an array of LEDs that light up with the image, but the electronics to make that happen are not exactly trivial. The solution? Find a small LCD panel and feed it from the same HDMI source as a big panel. Then place an array of LDRs on the front of the small LCD, driving an array of white LEDs through transistor drivers to make a new responsive backlight. We’re not sure we’d go to all this trouble, but it certainly looks quite c

FLOSS Weekly Episode 790: Better Bash Scripting with Amber

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This week Jonathan Bennett and Dan Lynch chat with Paweł Karaś about Amber, a modern scripting language that compiles into a Bash script. Want to write scripts with built-in error handling, or prefer strongly typed languages? Amber may be for you! – https://github.com/Ph0enixKM/Amber – https://amber-lang.com/ – https://docs.amber-lang.com/ Did you know you can watch the live recording of the show Right on our YouTube Channel ? Have someone you’d like use to interview? Let us know, or contact the guest and have them contact us! Take a look at the schedule here . Direct Download in DRM-free MP3. If you’d rather read along, here’s the transcript for this week’s episode . Places to follow the FLOSS Weekly Podcast: Spotify RSS from Blog – Hackaday https://ift.tt/uTYNdav

Google Drive Now Bootable

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USB drives are incredibly useful, both storing files for transport between different computers and for creating bootable drives that let us use or install other operating systems on our computers. While online file storage systems like Dropbox and Google Drive have taken over a large percentage of the former task from USB drives, they have not been able to act as bootable media, ensuring that each of us have a few jump drives lying around. That might not be the case anymore, though, as this guide is the first we know of to be able to use Google Drive to boot to a Linux system . Unlike the tried-and-true jump drive methods, however, this process is not straightforward at all. It relies on two keys, the first of which is FUSE which allows a filesystem to be created in userspace. The second is exploiting a step in boot process of Linux systems where the kernel unpacks a temporary filesystem, called initramfs , in order to load the real filesystem. Normally a user doesn’t interact much

Instant Filament Drying Satisfies an Immediate Need

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Most 3D printer filament soaks up water from the air, and when it does, the water passing through the extruder nozzle can expand, bubble, and pop, causing all kinds of mayhem and unwanted effects in the print. This is why reels come vacuum sealed. Some people 3D print so much that they consume a full roll before it can soak up water and start to display these effects. Others live in dry climates and don’t have to worry about humidity. But the rest of us require a solution. To date, that solution has been filament dryers, which are heated elements in a small reel-sized box, or for the adventurous an oven put at a very specific temperature until the reel melts and coats the inside of the oven. The downside to this method is that it’s a broad stroke that takes many hours to accomplish, and it’s inefficient because one may not use the whole roll before it gets soaked again. In much the same way that instant water heaters exist to eliminate the need for a water heater, [3DPI67] has a solu

Putting Some Numbers on Your NEMAs

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It’s official: [Engineer Bo] wins the internet with  a video titled “Finding NEMA 17,” wherein he builds a dynamometer to find the best stepper motor in the popular NEMA 17 frame size. Like a lot of subjective questions, the only correct answer to which stepper is best is, “It depends,” and [Bo] certainly has that in mind while gathering the data needed to construct torque-speed curves for five samples of NEMA 17 motors using his homebrew dyno. The dyno itself is pretty cool, with a bicycle disc brake to provide drag, a load cell to measure braking force, and an optical encoder to measure the rotation of the motor under test. The selected motors represent a cross-section of what’s commonly available today, some of which appear in big-name 3D printers and other common applications. [Bo] tested each motor with two different drivers: the TMC2209 silent driver to start with, and because he released the Magic Smoke from those, the higher current TB6600 module. The difference between the

Make a Cheap Robot Mower Much Smarter

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The Parkside range of tools as sold in European Lidl stores may be reasonably priced, but it contains some products of far better quality than their modest cost would suggest. This means that Parkside hacking has become as much of a cottage industry as IKEA hacking, and they’re a firm favorite for modifications. [Gabriel-LG] has taken a Parkside robot mower, and converted it from a relatively mundane device to a fully-connected smart robot , with the aid of an ESP32. The hardware is surprisingly simple, as all that’s really needed is a stop/go command. This can be readily found by hooking up to the input from the mower’s rain sensor, allowing the ESP to control its operation. Then there’s an accelerometer to allow it to count motion, and a hookup tot he battery to measure voltage. The firmware uses ESPHome, resulting in a mower now connected to home automation. This isn’t the first time we’ve shown you someone upgrading the smarts on  robot mover, and of course we’ve also taken a t

SIMD-Accelerated Computer Vision on the ESP32-S3

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One of the fun parts of the ESP32-S3 microcontroller is that it got upgraded to the newer Cadence Xtensa LX7 processor core, which turns out to have a range of SIMD instructions that can help to significantly speed up a range of tasks. [Shranav Palakurthi] recently used this to speed up the processing of video frames to detect corners using the FAST method. By moving some operations that benefit from SIMD over to an optimized version written in LX7 ASM, the algorithm’s throughput was increased by 220%, from 5.1 MP/s to 11.2 MP/s, albeit with some caveats. The problem with the SIMD instructions in the LX7 other than them being very poorly documented – unless you sign an NDA with Cadence –  is that it misses many instructions that would be really useful. For [Shranav] the lack of support for direct misaligned reads and comparing of unsigned 8-bit numbers were hurdles, but could be worked around, with the results available on GitHub. Much of the groundwork for this SIMD implementat

A DIY Proximity Sensor, Using Just Scrap Parts and Software

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[mircemk] shows how to create a simple non-contact proximity sensor using little more than an Arduino Nano board, and a convenient software library intended to measure the value of capacitors. The prototype has a threshold set via potentiometer for convenience. The basic idea is that it’s possible to measure a capacitor’s capacitance using two microcontroller pins and the right software, so by using a few materials to create an open-style capacitor, one can monitor it for changes and detect when anything approaches enough to alter its values past a given threshold, creating a proximity sensor. The sensor shown here is essentially two plates mounted side-by-side, attached to an Arduino Nano using the Capacitor library which uses just two pins, one digital and one analog. As configured, [mircemk]’s sensor measures roughly thirty picofarads, and that value decreases when approached by something with a dielectric constant that is different enough from the air surrounding the senso

Split A USB-C PD Port Into Three Port-ions

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There’s no shortage of USB-C chargers in all sorts of configurations, but sometimes, you simply need a few more charging ports on the go, and you got a single one. Well then, check out [bluepylons]’s USB-C splitter, which takes a single USB-C 5V/3A port and splits it into three 5V/1A plugs, wonderful for charging a good few devices on the go! This adapter does things right – it actually checks that 3A is provided, using a comparator, uses that to switch power to the three outputs, and correctly signals to the consumer devices that they may consume about 1A from the plugs. This hack’s documentation is super considerate – you get detailed instructions on how to reproduce it, every nuance you might want to keep in mind, and even different case options depending on whether you want to pot the case or instead use a thermal pad for a specific component which might have dissipate some heat during operation! This hack has been documented with notable care for whoever might want to walk the

Casting Concrete With A 3D-Printed Mould

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We’re accustomed to covering the use of 3D printing in casting, usually as a lost-PLA former in metal casting. That’s not the only use of the technique though, and perhaps one of the simplest is to use a 3D-printed mould for casting concrete. It’s what [ArtByAdrock] is doing in their latest video, casting an ornamental owl model. The first part of the video below the break deals with the CAD steps necessary to produce the mould, and depending on your CAD proficiency may not be the most interesting part. The process creates a mould with two halves, a pouring hole, and registration points. Then a 3D printer produces it using flexible TPU. The pour is then simplicity itself, using a casting cement mix at a consistency similar to pancake batter. The video shows how a release spray provides easy separation, and the result is a fresh concrete owl and a mould ready for the next pour. We can see that maybe readers have only so much space in their lives for concrete owls, but this process co

ChatGPT and Other LLMs Produce Bull Excrement, Not Hallucinations

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In the communications surrounding LLMs and popular interfaces like ChatGPT the term ‘hallucination’ is often used to reference false statements made in the output of these models. This infers that there is some coherency and an attempt by the LLM to be both cognizant of the truth, while also suffering moments of (mild) insanity. The LLM thus effectively is treated like a young child or a person suffering from disorders like Alzheimer’s, giving it agency in the process. That this is utter nonsense and patently incorrect is the subject of a treatise by [Michael Townsen Hicks] and colleagues, as published in Ethics and Information Technology . Much of the distinction lies in the difference between a lie and bullshit, as so eloquently described in [Harry G. Frankfurt]’s 1986 essay and 2005 book On Bullshit . Whereas a lie is intended to deceive and cover up the truth, bullshitting is done with no regard for, or connection with, the truth. The bullshitting is only intended to serve the i