The Billionth Repository On GitHub Is Really Shitty

June 12, 2025 by 40 Comments

What’s the GitHub repository you have created that you think is of most note? Which one do you think of as your magnum opus, the one that you will be remembered by? Was it the CAD files and schematics of a device for ending world hunger, or perhaps it was software designed to end poverty? Spare a thought for [AasishPokhrel] then, for his latest repository is one that he’ll be remembered by for all the wrong reasons. The poor guy created a repository with a scatalogical name, no doubt to store random things, but had the misfortune to inadvertently create the billionth repository on GitHub.

At the time of writing, the 💩 repository sadly contains no commits. But he seems to have won an unexpectedly valuable piece of Internet real estate judging by the attention it’s received, and if we were him we’d be scrambling to fill it with whatever wisdom we wanted the world to see. A peek at his other repos suggests he’s busy learning JavaScript, and we wish him luck in that endeavor.

We think everyone will at some time or another have let loose some code into the wild perhaps with a comment they later regret, or a silly name that later comes back to haunt them. We know we have. So enjoy a giggle at his expense, but don’t give him a hard time. After all, this much entertainment should be rewarded.

Cat at the door

2025 Pet Hacks Contest: Cat At The Door

June 12, 2025 by 14 Comments

This Pet Hacks Contest entry from [Andrea] opens the door to a great collaboration of sensors to solve a problem. The Cat At The Door project’s name is a bit of a giveaway to its purpose, but this project has something for everyone, from radar to e-ink, LoRa to 3D printing. He wanted a sensor to watch the door his cats frequent and when one of his cats were detected have an alert sent to where he is in the house

There are several ways you can detect a cat, in this project [Andrea] went with mmWave radar, and this is ideal for sensing a cat as it allows the sensor to sit protected inside, it works day or night, and it doesn’t stop working should the cat stand still. In his project log he has a chapter going into what he did to dial in the settings on the LD2410C radar board.

How do you know if you’re detecting your cat, some other cat, a large squirrel, or a small child? It helps if you first give your cats a MAC address, in the form of a BLE tag. Once the radar detects presence of a suspected cat, the ESP32-S3 starts looking over Bluetooth, and if a known tag is found it will identify which cat or cats are outside waiting.

Once the known cat has been identified, it’s time to notify [Andrea] that his cat is waiting for his door opening abilities. To do this he selected an ESP32 board that includes a SX1262 LoRa module for communicating with the portable notification device. This battery powered device has a low power e-paper display showing you which cat, as well as an audio buzzer to help alert you.

To read more details about this project head over to the GitHub page to check out all the details. Including a very impressive 80 page step-by-step guide showing you step by step how to make your own. Also, be sure to check out the other entries into the 2025 Pet Hacks Contest.

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End Of An Era: NOAA’s Polar Sats Wind Down Operations

June 12, 2025 by 16 Comments

Since October 1978, the National Oceanic and Atmospheric Administration (NOAA) has operated its fleet of Polar-orbiting Operational Environmental Satellites (POES) — the data from which has been used for a wide array of environmental monitoring applications, from weather forecasting to the detection of forest fires and volcanic eruptions. But technology marches on, and considering that even the youngest member of the fleet has been in orbit for 16 years, NOAA has decided to retire the remaining operational POES satellites on June 16th.

NOAA Polar-orbiting Operational Environmental Satellite (POES)

Under normal circumstances, the retirement of weather satellites wouldn’t have a great impact on our community. But in this case, the satellites in question utilize the Automatic Picture Transmission (APT), Low-Rate Picture Transmission (LRPT), and High Resolution Picture Transmission (HRPT) protocols, all of which can be received by affordable software defined radios (SDRs) such as the RTL-SDR and easily decoded using free and open source software.

As such, many a radio hobbyist has pointed their DIY antennas at these particular satellites and pulled down stunning pictures of the Earth. It’s the kind of thing that’s impressive enough to get new folks interested in experimenting with radio, and losing it would be a big blow to the hobby.

Luckily, it’s not all bad news. While one of the NOAA satellites slated for retirement is already down for good, at least two remaining birds should be broadcasting publicly accessible imagery for the foreseeable future.

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Learning The Basics Of Astrophotography Editing

June 12, 2025 by 13 Comments

Astrophotography isn’t easy. Even with good equipment, simply snapping a picture of the night sky won’t produce anything particularly impressive. You’ll likely just get a black void with a few pinpricks of light for your troubles. It takes some editing magic to create stunning images of the cosmos, and luckily [Karl Perera] has a guide to help get you started.

The guide demonstrates a number of editing techniques specifically geared to bring the extremely dim lights of the stars into view, using Photoshop and additionally a free software tool called Siril specifically designed for astrophotograpy needs. The first step on an image is to “stretch” it, essentially expanding the histogram by increasing the image’s contrast. A second technique called curve adjustment performs a similar procedure for smaller parts of the image. A number of other processes are performed as well, which reduce noise, sharpen details, and make sure the image is polished.

While the guide does show some features of non-free software like Photoshop, it’s not too hard to extrapolate these tasks into free software like Gimp. It’s an excellent primer for bringing out the best of your astrophotography skills once the pictures have been captured, though. And although astrophotography itself might have a reputation as being incredibly expensive just to capture those pictures in the first place, it can be much more accessible by using this Pi-based setup as a starting point.

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Crowdsourcing SIGINT: Ham Radio At War

June 12, 2025 by 18 Comments

I often ask people: What’s the most important thing you need to have a successful fishing trip? I get a lot of different answers about bait, equipment, and boats. Some people tell me beer. But the best answer, in my opinion, is fish. Without fish, you are sure to come home empty-handed.

On a recent visit to Bletchley Park, I thought about this and how it relates to World War II codebreaking. All the computers and smart people in the world won’t help you decode messages if you don’t already have the messages. So while Alan Turing and the codebreakers at Bletchley are well-known, at least in our circles, fewer people know about Arkley View.

The problem was apparent to the British. The Axis powers were sending lots of radio traffic. It would take a literal army of radio operators to record it all. Colonel Adrian Simpson sent a report to the director of MI5 in 1938 explaining that the three listening stations were not enough. The proposal was to build a network of volunteers to handle radio traffic interception.

That was the start of the Radio Security Service (RSS), which started operating out of some unused cells at a prison in London. The volunteers? Experienced ham radio operators who used their own equipment, at first, with the particular goal of intercepting transmissions from enemy agents on home soil.

At the start of the war, ham operators had their transmitters impounded. However, they still had their receivers and, of course, could all read Morse code. Further, they were probably accustomed to pulling out Morse code messages under challenging radio conditions.

Over time, this volunteer army of hams would swell to about 1,500 members. The RSS also supplied some radio gear to help in the task. MI5 checked each potential member, and the local police would visit to ensure the applicant was trustworthy. Keep in mind that radio intercepts were also done by servicemen and women (especially women) although many of them were engaged in reporting on voice communication or military communications.

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Open Source CAD In The Browser

June 12, 2025 by 43 Comments

Some people love tools in their browsers. Others hate them. We certainly do like to see just how far people can push the browser and version 0.6 of CHILI3D, a browser-based CAD program, certainly pushes.

If you click the link, you might want to find the top right corner to change the language (although a few messages stubbornly refuse to use English). From there, click New Document and you’ll see an impressive slate of features in the menus and toolbars.

The export button is one of those stubborn features. If you draw something and select export, you’ll see a dialog in Chinese. Translated it has the title: Select and a checkmark for “Determined” and a red X for “Cancelled.” If you select some things in the drawing and click the green checkmark, it will export a brep file. That file format is common with CAD programs, but you’ll need to convert, probably, if you want to 3D print your design.

The project’s GitHub repository shows an impressive slate of features, but also notes that things are changing as this is alpha software. The CAD kernel is a common one brought in via WebAssembly, so there shouldn’t be many simple bugs involving geometry.

We’ve seen a number of browser-based tools that do some kind of CAD. CADmium is a recent entry into the list. Or, stick with OpenSCAD. We sometimes go low-tech for schematics.

The green CRT display of a scanning-electron microscope is shown, displaying small particles.

DIY Calibration Target For Electron Microscopes

June 12, 2025 by 3 Comments

It’s a problem that few of us will ever face, but if you ever have to calibrate your scanning electron microscope, you’ll need a resolution target with a high contrast under an electron beam. This requires an extremely small pattern of alternating high and low-density materials, which [ProjectsInFlight] created in his latest video by depositing gold nanoparticles on a silicon slide.

[ProjectsInFlight]’s scanning electron microscope came from a lab that discarded it as nonfunctional, and as we’ve seen before, he’s since been getting it back into working condition. When it was new, it could magnify 200,000 times and resolve features of 5.5 nm, and a resolution target with a range of feature sizes would indicate how high a magnification the microscope could still reach. [ProjectsInFlight] could also use the target to make before-and-after comparisons for his repairs, and to properly adjust the electron beam.

Since it’s easy to get very flat silicon wafers, [ProjectsInFlight] settled on these as the low-density portion of the target, and deposited a range of sizes of gold nanoparticles onto them as the high-density portion. To make the nanoparticles, he started by dissolving a small sample of gold in aqua regia to make chloroauric acid, then reduced this back to gold nanoparticles using sodium citrate. This gave particles in the 50-100 nanometer range, but [ProjectsInFlight] also needed some larger particles. This proved troublesome for a while, until he learned that he needed to cool the reaction temperature solution to near freezing before making the nanoparticles.

Using these particles, [ProjectsInFlight] was able to tune the astigmatism settings on the microscope’s electron beam so that it could clearly resolve the larger particles, and just barely see the smaller particles – quite an achievement considering that they’re under 100 nanometers across!

Electron microscopes are still a pretty rare build, but not unheard-of. If you ever find one that’s broken, it could be a worthwhile investment.

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