A Homebrew AC Upgrade For The Fluke 8840A

October 20, 2022 by 9 Comments

[William Dudley] picked up a Fluke 8840A bench multimeter at an auction, but was sad to find out that it was reading resistances inaccurately. It was also missing the optional board to enable AC measurements. Desiring to use the otherwise lovely meter, he set about repairing and upgrading the device.

Thankfully, the 8840A was from a time when Fluke used to openly publish schematics in its manuals. Thus, combined with taking a look at some photos online, it was straightforward for [William] to recreate the original AC “Option 09” board to enable the desired functionality. As is usually the way, his efforts didn’t work first time, but after some bodge wires were installed, all was well. [William] reports the measurements are “reasonable, maybe even sufficient” with no calibration undertaken.

Repairing the resistance issue was easy. It turned out to be corrosion on the selector switches, revealed when high-resistance measurements were accurate, but low-resistance measurements weren’t. A bit of flick-flacker with some contact cleaner sprayed into the switches got things working again nicely.

It’s nice to see old hardware restored to full functionality, particularly when it’s as attractive and well-built as an old Fluke meter. Bringing back old tools from the dead? You know we wanna hear about it!

ERRF 22: Building A Library Of Filament Colors

October 20, 2022 by 10 Comments

If you’ve ever paged through the color samples at the hardware store trying to match a particular color, you know how hard it can be. Not only are there nearly limitless color variations, but each manufacturer has their own formulas and tints. Often times, the only way to get the exact color you need is to get it custom mixed.

Unfortunately, that’s not really an option when it comes to filament for your 3D printer. Will that roll of orange from Hatchbox actually match the orange from Overture? That’s where the Filament Librarian comes in. Created by [Joe Kaufeld], the project aims to catalog and photograph as many 3D printer filaments as possible so you can see exactly what you’re getting.

Now of course, if it was as easy as looking at pictures of filament swatches on your computer, you wouldn’t need this service to begin with. So what’s the trick? A custom automated camera rig, powered by the Raspberry Pi, is used to position, light, and photograph each filament sample in the library. So while [Joe] can’t promise your monitor is showing a perfect representation of each filament’s color, you can at least be sure they will all look correct in relation to each other. So for example, the site can help you figure out if the local Microcenter stocks anything that comes close to matching Prusament’s Galaxy Silver PLA.

[Joe] brought a collection of his samples along with his slick camera setup to the 2022 East Coast RepRap Festival so attendees could see first-hand how he adds a new filament to the database. With an easy-to-use touch-screen interface, it takes just seconds to get the camera ready for the next shot.

Now that he’s got the hardware and the procedure down, [Joe] is asking the community to help out by providing him with filament samples to process. It doesn’t take much: all he asks is you snip him off a couple meters of filament, write down what it is and who makes it on a pre-made form, and drop it in the mail. If you’re in the US, you can send it directly to his address in Indiana, and for those on the other side of the globe, he’s got a drop point in the Netherlands you can use.

We love a good passion project here at Hackaday, so here’s hoping that the Filament Librarian receives plenty of new filament samples from all over the planet to feed into that fancy camera setup of his.

An ortholinear keyboard with predominantly blank white keycaps. There are two red keycaps on the bottom outside corners. The center of the keyboard houses a large LCD in portrait orientation on a red PCB.

2022 Cyberdeck Contest: Keezyboost40 Is A Cyberdeck Masquerading As A Keyboard

October 20, 2022 by 5 Comments

There’s something to be said for über-powerful cyberdecks, but there’s also a certain appeal to less powerful decks squeezed into a tiny form factor. [Christian Lo] has designed a cyberdeck that looks like a simple ortholinear keyboard but is running a more flexible environment.

There are games and animations you can play on QMK, but [Lo] felt that a different framework would give him more flexibility to really stretch the limits of what this Raspberry Pi Pico-powered deck could do. He decided to go with a Rust-based firmware with the keyberon library and says, “it felt like I was in control of the firmware.” While the board is using Rust for now, [Lo] says he’s open to conversations about other firmware options to achieve his goals, like a virtual pet game for the board.

The PCB is described as “bog standard” with the possible exception of placing the Pi in a cutout on the board to keep things as low profile as possible. The trade-off comes in the form of reduced board rigidity and potentially increased strain on the connections to the microcontroller.

Looking for more cool cyberdecks? Check out the Winners of the 2022 Cyberdeck Contest or go see all the entries on the Contest Page.
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2022 Hackaday Supercon: Final Talks Announced

October 20, 2022 by 2 Comments

The third and final round of the 2022 Supercon talks announcements brings us closer to a complete picture of the full spectrum of hacking awesomeness taking the stage in just a few weeks. (And we haven’t even announced the keynote yet!)

Supercon is the Ultimate Hardware Conference and you need to be there! We’ll continue to announce speakers and workshops over the next couple weeks. Supercon will sell out so get your tickets now before it’s too late. And stay tuned for the next round of talk reveals next week! Continue reading “2022 Hackaday Supercon: Final Talks Announced” →

Forearm Muscle Contraction Sensor Is Useful Component For Open Source Prosthetics

October 20, 2022 by 2 Comments

Being able to actuate parts of a prosthetic limb can make it much more useful. To help in this goal for partial arm or hand amputees, [TURFPTAx] has developed a sensor for detecting forearm muscle contractions. 

The sensor itself is cost-effective and simple to build.

The build is part of the Open Prosthetics project, which aims to offer open designs for various types of prosthetic devices. It apes common commercial designs using a simple electromechanical system.

The build relies on magnets mounted on twelve pistons that move when the muscles contract under the skin. The pistons are sprung to allow them to follow the expansion and contractions of the muscles, and the motion of the magnets is detected by hall effect sensors. The system is bulkier than some other solutions, but has the benefit of clean output and the ability to detect the movement of several distinct muscle groups. The data is all collected by an ESP32 which is then sent wirelessly to a computer for measurement, with [TURFPTAx] using the PyGame library to plot the sensor data.

[TURFPTAx] notes that the output of the sensors would be perfect to input into a machine learning system. Video after the break.

Continue reading “Forearm Muscle Contraction Sensor Is Useful Component For Open Source Prosthetics” →

Retrotechtacular: The Original Weather Channel

October 20, 2022 by 22 Comments

The Weather Channel has decided to pull the plug on its automated weather display, a favorite experience for weather geeks everywhere. However, it wasn’t the original weather nerd TV station.  Early cable TV networks had their own low-tech versions of this much longer ago than you might expect. For example, check out the video below which shows one of these weather stations back in 1975.

The audio was from a local FM station and you can enjoy handwritten public service announcements, as well.

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Render Yourself Invisible To AI With This Adversarial Sweater Of Doom

October 20, 2022 by 57 Comments

Ugly sweater season is rapidly approaching, at least here in the Northern Hemisphere. We’ve always been a bit baffled by the tradition of paying top dollar for a loud, obnoxious sweater that gets worn to exactly one social event a year. We don’t judge, of course, but that’s not to say we wouldn’t look a little more favorably on someone’s fashion choice if it were more like this AI-defeating adversarial ugly sweater.

The idea behind this research from the University of Maryland is not, of course, to inform fashion trends, nor is it to create a practical invisibility cloak. It’s really to probe machine learning systems for vulnerabilities by making small changes to the input while watching for changes in the output. In this case, the ML system was a YOLO-based vision system which has little trouble finding humans in an arbitrary image. The adversarial pattern was generated by using a large set of training images, some of which contain the objects of interest — in this case, humans. Each time a human is detected, a random pattern is rendered over the image, and the data is reassessed to see how much the pattern lowers the object’s score. The adversarial pattern eventually improves to the point where it mostly prevents humans from being recognized. Much more detail is available in the research paper (PDF) if you want to dig into the guts of this.

The pattern, which looks a little like a bad impressionist painting of people buying pumpkins at a market and bears some resemblance to one we’ve seen before in similar work, is said to work better from different viewing angles. It also makes a spiffy pullover, especially if you’d rather blend in at that Christmas party.