Wimbledon Goes Automated

October 10, 2024 by 4 Comments

When you think of tennis, you probably think of Wimbledon, the All England Club’s famous competition that has run for 147 years. Part of that history has always been line judges who call the ball in or out, sometimes to the ire of players and fans alike. But line judges will be no more at Wimbledon. They are moving to ELC or electronic line calling on all courts in both the main draw and the qualifying tournaments, according to [Tumaini Carayol] writing in The Guardian.

Of course, in 2007, the competition started using “Hawk-Eye,” which allows for review and challenges of the calls. ELC has also been used in other venues, such as the US Open, which has also done away with all line judges.

In fact, the only grand slam tournament that isn’t using ELC now is the French Open. There is some concern, however. The increased availability of line judges will cut down on the demand for new line judges at lesser tournaments. However, these jobs are a common pathway for aspiring chair judges to gain experience and exposure.

According to the Bloomberg video below, the system uses cameras and microphones to keep track of the ball’s position. Other reports say there are 18 cameras and, apparently, the system uses a computer-generated voice to call “out,” “fault,” or “foot fault.”

Apparently, there are some downsides, however. Last month at the US Open, play was halted because the remote office of the technicians operating the ELC system had to evacuate due to a fire alarm.

[Lewin Day] thinks tech will ruin sports. He may be right. Of course, we are more likely to play sports on technology.

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The Punched Card Detective

October 9, 2024 by 31 Comments

[John Graham-Cumming] might not be the first person to thumb through an old book and find an IBM punched card inside. But he might be the first to actually track down the origin of the cards. Admittedly, there were clues. The book was a Portuguese book about computers from the 1970s. The cards also had a custom logo on them that belonged to a computer school at the time.

A Hackaday card, thanks to the online card punch

It is hard to remember, but there was a time when cards reigned supreme. Sometimes called Hollerith cards after  Herman Hollerith, who introduced the cards to data processing, these cards used square holes to encode information. Reading a card is simple. There are 80 columns on a classic card. If a column has a single punch over a number, then that’s what that column represents. So if you had a card with a punch over the “1” followed by a punched out “5” in the next column and a “0” in the column after that, you were looking at 150. No punches, of course, was a space.

So, how did you get characters? The two blank regions above the numbers are the X and Y zones (or, sometimes, the 11 and 12 zones). The “0” row was also sometimes used as a zone punch. To interpret a column, you needed to know if you expected numbers or letters. An 11-punch with a digit indicated a negative number if you were expecting a number. But it could also mean a particular letter of the alphabet combined with one or more punches in the same column.

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On-Site Viral RNA Detection In Wastewater With Paper And Wax Microfluidics

October 9, 2024 by 4 Comments
Schematic version of on-site wastewater analysis using the microfluidic strips (Credit: Yuwei Pan et al., Cell, 2024)

Wastewater sampling has become a popular way over the years to keep track of the health of a population, including human ones, as pathogens are often detectable in the effluence from toilets. Since most houses connected to the centralized sewer systems, this means that a few sampling sites suffice to keep tabs on which viruses are circulating in an area. While sampling this wastewater is easy, the actual RNA analysis using PCR (polymerase chain reaction) still has to be performed in laboratories, adding complex logistics. An approach for on-site analysis using microfluidics was tested out by [Yuwei Pan] et al., as recently published in Cell.

This particular approach uses RT-LAMP (reverse-transcription loop-mediated isothermal amplification) to increase the amount of genetic material, which has the significant benefit over PCR that it does not require multiple thermal cycles, instead being run at a constant temperature. The filter paper used as the basis has wax microchannels printed on it, which help to guide the filtered wastewater to the reaction chambers. This is in many ways reminiscent of the all too familiar linear flow self-tests (RAT: rapid antigen test) that have become one of the hallmarks of the SARS-CoV-2 pandemic.

What this paper microfluidic device adds is that it doesn’t merely contain antigens, but performs the lysis (i.e. breakdown of the virus particles), genetic material multiplication using RT-LAMP and subsequent presence detection of certain RNA sequences to ascertain the presence of specific viruses. Having been used in the field already since 2020 in the UK, the researchers envision this type of on-site analysis to be combined with a smartphone for instant recording and transmission to health authorities.

Some of the benefits of this approach would be lower cost, easier logistics and faster results compared to shipping wastewater samples to central laboratories.

3D Printed Bearings With Filament Rollers

October 9, 2024 by 24 Comments

Commodity bearings are a a boon for makers who to want something to rotate smoothly, but what if you don’t have one in a pinch? [Cliff] of might have the answer for you, in the form of 3D printed bearings with filament rollers.

With the exception of the raw filament rollers, the inner and outer race, roller cage and cap are all printed. It would also be possible to design some of the components right into a rotating assembly. [Cliff] makes it clear this experiment isn’t about replacing metal bearings — far from it. Instead, it’s an inquiry into how self-sufficient one can be with a FDM 3D printer. That didn’t stop him from torture testing the design to its limits as wheel bearings on an off-road go-cart. The first version wasn’t well supported against axial loads, and ripped apart during some more enthusiastic maneuvers.

[Cliff] improved it with a updated inner race and some 3D printed washers, which held up to 30 minutes of riding with only minimal signs of wear. He also made a slightly more practical 10 mm OD version that fits over an M3 bolt, and all the design files are downloadable for free. Cutting the many pieces of filament to length quickly turned into a chore, so a simple cutting jig is also included.

Let us know in the comments below where you think these would be practical. We’ve covered some other 3D printed bearing that use printed races, as well as a slew bearing that’s completely printed. Continue reading “3D Printed Bearings With Filament Rollers” →

Fail Of The Week: The Case Of The Curiously Colored Streetlights

October 9, 2024 by 116 Comments

What color are the street lights in your town? While an unfortunate few still suffer under one of the awful colors offered by vapor discharge lamps, like the pink or orange of sodium or the greenish-white of mercury, most municipalities have moved to energy-saving LED streetlights, with a bright white light that’s generally superior in every way. Unless, of course, things go wrong and the lights start to mysteriously change colors.

If you’ve noticed this trend in your area, relax; [NanoPalomaki] has an in-depth and surprisingly interesting analysis of why LED streetlights are changing colors. After examining a few streetlights removed from service thanks to changing from white to purple, he discovered a simple explanation. White LEDs aren’t emitting white light directly; rather, the white light comes from phosphors coating the underlying LED, which emits a deep blue light. The defunct units all showed signs of phosphor degradation. In some cases, the phosphors seemed discolored, as if they experienced overheating or chemical changes. In other LEDs the phosphor layer was physically separated from the backing, exposing the underlying LEDs completely. The color of these damaged modules was significantly shifted toward the blue end of the spectrum, which was obviously why they were removed from service.

Now, a discolored LED here and there does not exactly constitute a streetlight emergency, but it’s happening to enough cities that people are starting to take notice. The obvious solution would be for municipalities to replace the dodgy units Even in the unlikely event that a city would get some compensation from the manufacturer, this seems like an expensive proposition. Luckily, [NanoPalomaki] tested a solution: he mixed a wideband phosphor into a UV-curable resin and painted it onto the lens of each defective LED in the fixture. Two coats seemed to do the trick.

We have to admit that we have a hard time visualizing a city employee painstakingly painting LEDs when swapping out a fixture would take an electrician a few minutes, but at least it’s an option. And, it’s something for hobbyists and homeowners faced with the problem of wonky white LEDs to keep in mind too.

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FLOSS Weekly Episode 804: The AI Alliance — Asimov Was Right

October 9, 2024 by 1 Comment

This week Jonathan Bennett and and Dan Lynch chat with Anthony Annunziata about Open Source AI and the AI Alliance. We get answers to our burning AI questions, and talk about the difficulty of defining what Open Source means for these large models.

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Braun TS2 Radio Turns 68, Gets Makeover

October 9, 2024 by 7 Comments

The Braun TS2 radio was a state-of-the art tube set in 1956. Today it still looks great, but unsurprisingly, the one that [Manuel Caldeier] has needed a little tender loving care. The table radio had a distinct style for its day and push-buttons. However, the dial glass and the speaker grill needed replacement. Even more interesting, the radio has a troublesome selenium rectifier, giving him the perfect chance to try out his new selenium rectifier solid-state replacement.

The radio is as good-looking inside as it is outside. You can tell that this isn’t his first restoration, as he has several tricks to test things at different stages of the project.

While the radio looked good, it smelled of smoke, which required a big effort to clean. The dial glass was intact enough for him to duplicate it in a graphic program and print it on a transparent adhesive sticker. With a deep breath, he removed the original markings from the glass so he could add the sticker to it. That didn’t work because the label needed cutouts. So now he is waiting for a piece of acrylic that will have the art UV printed on it.

We want to see the next part as we imagine the radio sounds as good as it looks when it is working. If you want to know more about the rectifier replacement, we covered that earlier. Even years later, Braun would have a clean aesthetic.

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