Modular Anti-Drone Drone Sacrifices Itself For Self Defense

April 22, 2022 by 18 Comments

Part Racing Drone, Part RC Airplane, Part Rocket…all Menace. How else could you describe a quadcopter that shoots off at high speed and is designed for taking down other small quadcopters? The Interceptor Drone by [Aleksey] borrows elements from all of the aforementioned disciplines of flying things.

Built with standard racing drone parts, [Aleksey] assures that no prohibited parts are used in its construction. Instead, the Interceptor Drone relies on a very powerful motors and a light weight frame to keep the power to weight ratio in the “rocketing into the sky” category.

A close up shows the details: Detachable motors and rotors and the stowed net.

But what Interceptor Drone would be complete without a way to take its target out of the sky? This is where the biggest divergences begin. The motors are all oriented to point away from the center-line of the craft. Upon command, these motors actually detach from the frame, each spreading out and deploying the corner of a net that’s designed to entangle the rotors of the target, causing its battle with gravity to come to a grinding halt.

How does the Interceptor Drone survive the attack? Without its motors, the core of the quadcopter falls to the earth. Arresting the fall is a parachute much like those used in model rocketry. An audio beacon sounds the alarm to help somebody to find it — a move taken straight from the RC aircraft hobby.

There’s certainly a lot of room to discuss legalities in localities, but regardless of opinion about the craft’s intended use, the system looks very slick, and there are some great hacks baked right in. Don’t want to build a drone-killing-drone? Maybe all you need is a pumpkin and good (bad?) timing.

Continue reading “Modular Anti-Drone Drone Sacrifices Itself For Self Defense” →

A man performing push-ups in front of a PC

Machine Learning Helps You Get In Shape While Working A Desk Job

April 22, 2022 by 9 Comments

Humans weren’t made to sit in front of a computer all day, yet for many of us that’s how we spend a large part of our lives. Of course we all know that it’s important to get up and move around every now and then to stretch our muscles and get our blood flowing, but it’s easy to forget if you’re working towards a deadline. [Victor Sonck] thought he needed some reminders — as well as some not-so-gentle nudging — to get into the habit of doing a quick workout a few times a day.

To this end, he designed a piece of software that would lock his computer’s screen and only unlock it if he performed five push-ups. Locking the screen on his Linux box was as easy as sending a command through the network, but recognizing push-ups was a harder task for which [Victor] decided to employ machine learning. A Raspberry Pi with a webcam attached could do the trick, but the limited processing power of the Pi’s CPU might prove insufficient for processing lots of raw image data.

[Victor] therefore decided on using a Luxonis OAK-1, which is a 4K camera with a built-in machine-learning processor. It can run various kinds of image recognition systems including Blazepose, a pre-trained model that can recognize a person’s pose from an image. The OAK-1 uses this to send out a set of coordinates that describe the position of a person’s head, torso and limbs to the Raspberry Pi through a USB interface. A second machine-learning model running on the Pi then analyzes this dataset to recognize push-ups.

[Victor]’s video (embedded below) is an entertaining introduction into the world of machine-learning systems for video processing, as well as a good hands-on example of a project that results in a useful tool. If you’re interested in learning more about machine learning on small platforms, check out this 2020 Remoticon talk on machine learning on microcontrollers, or this 2019 Supercon talk about implementing machine vision on a Raspberry Pi.

Continue reading “Machine Learning Helps You Get In Shape While Working A Desk Job” →

Optimized Super Mario 64 Offers Exciting Possibilities

April 21, 2022 by 13 Comments

When working on any software project, the developers have to balance releasing on time with optimizations. As long as you are hitting your desired time constraints, why not just ship it earlier? It’s no secret that Super Mario 64, a hotly anticipated launch title for the Nintendo 64 console in 1996, had a lot of optimizations left on the table in order to get it out the door on time. In that spirit, [Kaze Emanuar] has been plumbing the depths of the code, refactoring and tweaking until he had a version with serious performance gains.

Why would anyone spend time improving the code for an old game that only runs on hardware released over two decades ago? There exists a healthy modding community for the game, and many of the newer levels that people are creating are more ambitious than what the original game could handle. But with the performance improvements that [Kaze] has been working on, your budget for larger and more complex levels suddenly becomes much more significant. In addition, it’s rumored that a multi-player mode was originally planned for the game, but Nintendo had to scrap the feature when it was found that the frame rate while rendering two cameras wasn’t up to snuff. With these optimizations, the game can now handle two players easily.

Luigi has been waiting 26 years for his chance to shine.

[Kaze] has a multi-step plan for improving the performance involving RAM alignment, compiler optimizations, rendering improvements, physics optimizations, and generally reducing “jankiness.” To be fair to the developers at Nintendo, back then they were working with brand new hardware and pushing the boundaries of what home consoles were capable of. Modeling software, toolchains, compilers, and other supporting infrastructure have vastly improved over the last 20+ years. Along the way, we’ve picked up many tricks around rendering that just weren’t as common back then.

The central theme of [Kaze]’s work is optimizing Rambus usage. As the RCP and the CPU have to share it, the goal is to have as little contention as possible. This means laying out items to improve cachability and asking the compiler to generate smaller code rather than faster code (no loop unrolling here). In addition, certain data structures can be put into particular regions of memory that are write-only or read-only to improve resource contention. Logic bugs are fixed and rendering techniques were improved. The initial results are quite impressive, and while he isn’t done, we’re very much looking forward to playing with the final product.

With the Nintendo 64 on its way to becoming a mainline-supported Linux platform, the old console is certainly seeing a lot of love these days.

Continue reading “Optimized Super Mario 64 Offers Exciting Possibilities” →

Electric Chopsticks Bring The Salt, Not The Pain

April 21, 2022 by 12 Comments

The Japanese people love their salt, perhaps as much as Americans love their sugar high fructose corn syrup and caffeine. But none of these are particularly good for you. Although humans do need some salt in their diets to continue existing, the average Japanese person may be eating too much of it on a regular basis — twice the amount recommended by the World Health Organization, according to Reuters. Cue the invention of electric chopsticks, which provide salty flavor without the actual sodium.

No, you won’t get shocked — not even a fresh 9 V to the tongue’s worth. The tips of the chopsticks are made of something food-safe and conductive, and one is wired to a bracelet that contains a small computer. Using a weak current, the chopsticks transmit sodium ions from the food to the tongue, which increases the perceived saltiness by 1.5x. The device was co-created by a Meiji University professor and a Japanese beverage maker, who hope to commercialize it sometime next year.

This isn’t the first time humans have used trickery when it comes to diets. The older among you may remember the miracle berry weight loss craze of the 1970s. When ingested first, miracle berries make sour things taste sweet, so chowing down on grapefruits and lemons suddenly sounds like a good idea. What people failed to realize was that the acidity would still wreak havoc on their teeth and tongues, leaving them regretful the next day.

Images via Reuters

Car Hacker Hacks Lawn Care Carb Into Hot Rod Car

April 21, 2022 by 45 Comments

Internal combustion engines have often been described (quite correctly) as air pumps, and because of this nature, they tend to respond very well to more air. Why? Because more air means more fuel, and more fuel means more power- the very nature of hot rodding itself. [Thunderhead289] is an accomplished car hacker, and he’s decided to take things the opposite direction: Less air, less fuel… more mileage? As you can see in the video below the break, [Thunderhead289] has figured out how to mount a single barrel carburetor from a lawn mower to the four barrel intake of a Ford 302– a V8 engine that’s many times larger than the largest single cylinder lawnmower!

The hacks start not just with the concept, but with getting the carburetor installed. Rather than being a downdraft carburetor, the new unit is a side draft, with the float bowl below the carb’s venturi. To mount it, a 3d printed adapter was made, which was no small feat on its own. [Thunderhead289] had to get quite creative and even elevate the temperature of his workshop to over 100 degrees Fahrenheit (38 Celsius) to get the print finished properly. Even then, the 34 hour print damaged his Ender printer, but not before completing the part.

The hackery doesn’t stop there, because simply mounting the carburetor is only half the battle. Getting the engine to run properly with such a huge intake restriction is a new task all its own, with a deeper dive into fuel pressure management, proper distributor timing, and instrumenting the car to make sure it won’t self destruct due to a poor fuel mixture.

While [Thunderhead289] hasn’t been able to check the mileage of his vehicle yet, just getting it running smoothly is quite an accomplishment. If silly car hacks are your thing, check out [Robot Cantina]’s 212cc powered Insight and how they checked the output of their little engine. Thanks to [plainspicker] for the tip!

Continue reading “Car Hacker Hacks Lawn Care Carb Into Hot Rod Car” →

Scanning Receipts Proves Trickier Than Anticipated

April 21, 2022 by 25 Comments

It’s one of those things that certainly sounds simple enough: take a picture of a receipt, run it through optical character recognition (OCR), and send the resulting information to whatever expense-tracking website or software you wish. There are companies that offer such a service, so it can’t be too difficult to replicate on your own…right?

That’s what [Marcel Robitaille] thought when he set out to create his homebrew “Receipt Ingestion” system, anyway. But in reality it took so much time to troubleshoot and implement that he says it would have been faster to just enter in all his receipts by hand. We’re happy he stuck with it though, otherwise you wouldn’t be reading about it on Hackaday, and we wouldn’t be able to learn anything from the detailed account he’s provided.

It only took an evening to hack together a rough demo, and the initial results were very promising. The code could detect the edges of the receipt, rotate the captured image appropriately, and then pull out the critical information such as date, total amount, business name, etc. He was then able to decipher the API for Splitwise, an online service for splitting bills, by capturing the data sent by his browser while adding a new bill. With this information, writing up some Python code to push his captured data into the service was trivial. So far, so good.

Using a QR code as reference point.

But like so many horror films that begin with a happy family starting a new life in a beautiful home, there was a monster lurking in the shadows. It’s one thing to capture data from perfectly clean and flat receipts, but quite another to get any useful info out of one that spent half the day crumpled up in your back pocket. The promising proof of concept that worked a treat under controlled conditions failed completely in the real-world, with [Marcel] reporting that only 1 in 5 receipts he tried to scan actually went through.

In the end, [Marcel] realized that the best way to handle the unreliable condition of the receipts was to focus on a different object in the image. He came up with a QR code marker that he could put on the table with the receipt to be scanned, which his software can use as a known point of reference. This greatly improves the reliability of the image rotation and transformation, which in turn makes the OCR more reliable. It also makes it much easier to tell which images need to be scanned — if there’s no QR code found, the software just skips that shot and keeps looking.

The unique challenges of digitizing large amounts of printed content using OCR makes for some fascinating problem solving, and we’re glad [Marcel] shared this particular story with us. While there’s still some edge cases that need chasing down, he’s using the software on a nearly daily basis, and has posted it up on GitHub for anyone who might wish to build on his efforts.

2022 Sci-Fi Contest: A Star Wars Mouse Droid Of Your Very Own

April 21, 2022 by 5 Comments

The show-stealing droids of Star Wars, R2-D2 and C-3PO, are quite challenging to replicate at home, due to their size and complexity. [curiousmarc] had built the former, with much work going into drawing and design. The more humble Mouse Droid, as seen skittering about the halls of the Death Star, is a considerably easier build — especially with this somewhat improvised approach.

The build relies on reject parts from [curiousmarc]’s R2-D2 build, and other stuff laying around the house, like a toy eggbeater, a VFD, and other electronic bits and pieces. An RC car chassis was placed in the droid’s vacuum-formed shell in order to provide propulsion, with much of the rest of the work being decoration of the housing with various sci-fi ephemera. There’s also a pair of Arduinos inside, controlling the VFD, sound output, and the movable antenna dish on top.

It’s a build with a lot of personality. The sounds, flickering display, and moving antenna do a lot to imbue this droid with a soul, something Lucasfilm readily achieved with many of the robots in the series. It’s something we’ve also seen in robot companion builds from [Jorvon Moss], which are quite sci-fi in their own way, too. Video after the break.

Continue reading “2022 Sci-Fi Contest: A Star Wars Mouse Droid Of Your Very Own” →