Drone Buoy Drifts Along The Gulf Stream For Citizen Science

August 13, 2020 by Dan Maloney 26 Comments

It may be named after the most famous volleyball in history, but “Wilson” isn’t just a great conversationalist. [Hayden Brophy] built the free-drifting satellite buoy to see if useful science can be done with off-the-shelf hardware and on a shoestring budget. And from the look of the data so far, Wilson is doing pretty well.

Wilson belongs to a class of autonomous vessels known as drifters, designed to float along passively in the currents of the world’s ocean. The hull of [Hayden]’s drifter is a small Pelican watertight case, which contains all the electronics: Arduino Pro Trinket, GPS receiver, a satellite modem, and a charger for the LiPo battery. The lid of the case is dominated by a 9 W solar panel, plus the needed antennas for GPS and the Iridium uplink and a couple of sensors, like a hygrometer and a thermometer. To keep Wilson bobbing along with his solar panel up, there’s a keel mounted to the bottom of the case, weighted with chains and rocks, and containing a temperature sensor for the water.

Wilson is programmed to wake up every 12 hours and uplink position and environmental data as he drifts along. The drifter was launched into the heart of the Gulf Stream on August 8, about 15 nautical miles off Marathon Key in Florida, by [Captain Jim] and the very happy crew of the “Raw Deal”. As of this writing, the tracking data shows that Wilson is just off the coast of Miami, 113 nautical miles from launch, and drifting along at a stately pace of 2.5 knots. Where the buoy ends up is anyone’s guess, but we’ve seen similar buoys make it all the way across the Atlantic, so here’s hoping that hurricane season is kind to Wilson.

We think this is great, and congratulations to [Hayden] for organizing a useful and interesting project.

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Head-Tracking NES Water Blaster Is Good Summer Fun

August 13, 2020 by Lewin Day 1 Comment

Super Soakers were great fun back in the day, but adults tend to get tired of the manual labour of pumping pretty quickly. [Sean] decided to build something a touch more modern, coming up with this head-tracking water blaster.

The water spray tracks the movement of the wearer’s head. With a camera mounted on the nozzle, this allows the user to simply look to designate targets. Similar technology is used in military fighter jets.

To eliminate pumping, the build instead enlists the services of an electric pump, powered by a 12 V battery. Pushing water through a tube into a 3D printed nozzle, it provides a fat stream of water with around 5 meters range, with little effort from the user. The nozzle is fitted into a NES Zapper, and attached to a servo pan-tilt platform. The camera is mounted on the water gun, and hooked up to a set of Fat Shark FPV goggles with an IMU unit. When the user looks around, the water gun moves in sync with their head movements. This allows for the user to look at targets to hit them with the water stream, a very intuitive method of aiming.

It’s a fun build that’s perfect for the summer, and an easy one to recreate for anyone with some spare servos and FPV gear. Of course, with a little face-tracking software, it would be easy to hit targets automatically. Video after the break.

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Scratch Build Of This Tiny RC Car Is A Handmade Fabrication Masterpiece

August 12, 2020 by Lewin Day 27 Comments

Tiny remote control cars burst onto the scene from time to time, often sold from mall kiosks and covered in garish stickers. However, sometimes it’s more fun to build than to buy. [diorama111] clearly fits into this camp, building a tiny 1:150 scale RC car from the ground up.

The build starts with a Tomy 1:150 model Toyota Crown / Avalon. However, only the outer shell remain. From giving the wheels rubber tires and fabricating a delicate steering assembly, to adding motors for both locomotion and turning, the mechanical build is on point. But seeing the ATtiny1616 is deadbugged with a DRV8835 motor driver, with the SMD parts hooked up with magnet wire to save the most space possible is equally impressive. A PIC79603 IR module is used to receive the commands to drive the car.

The build is an artful one, and all done by hand — no 3D printing or CNC parts involved. Watching the car drive is a delight. The smooth analog steering and slow speed give it an excellent scale appearance. The only thing we wonder about is the difficulty of driving it quickly without the aid of self-centering steering. It reminds us fondly of the 1:96 scale fully-functional Mustang RC plane we featured in 2017. Video after the break. Continue reading “Scratch Build Of This Tiny RC Car Is A Handmade Fabrication Masterpiece” →

A Song Of Fog And Fire – Taking A Look Inside A Rubens’ Tube

August 12, 2020 by Sven Gregori 2 Comments

The dark winter months are still a bit ahead of us, but with night returning even to the northernmost places, it might be a good time to get your next mood lighting project started. Despite the ubiquitousness of LED strips, cave-time nostalgia makes it hard to beat the coziness of an actual flame here — well, assuming it’s a controlled flame. While modern LED candles do a decent enough job to fool you from a distance, there’s one apparatus they’ll have a hard time to replicate though: the Rubens’ tube. Tired of their usual straight pipe construct, [RyanMake] added some twists and turns to the concept and created a flexible Ruben’s tube made from semi-rigid aluminum ducts.

If you’re not familiar with the Rubens’ tube, it’s a combination of science, fun, and danger to visualize standing waves with fire by attaching a loudspeaker to a pipe with equally spaced holes that’s filled with flammable gas, and light it up. As the resulting visual effect depends on the audio signal’s wavelength, and by that the length of the tube itself, [RyanMake]’s flexible duct approach adds some variety to the usual fixed-length pipe versions of it. But that’s not all he did. After seeing the flames in person, he got curious about what’s actually going on inside that tube and decided to build another one, this time using a clear plastic tube and a fog machine. While the fog escapes the tube rather unimpressively (and could hardly compete with fire anyway), it gives a nice insight of what’s going on inside those tubes. See for yourself in the videos after the break.

Of course, no experiment is truly conducted without failure, and after seeing his first tube go up in flames several times, you should probably hold on to building one as decorative item for indoors. On the other hand, if shooting fire is what you’re looking for, you might be interested in this vortex cannon. And for some more twists on a standard Rubens’ tube, check out the two-dimensional Pyro Board.

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Floppy Disks Still Used To Update 747 Flight Software

August 12, 2020 by Lewin Day 96 Comments

For garden variety daily computing tasks, the floppy disk has thankfully been a thing of the past for quite some time. Slow, limited in storage and easily corrupted, few yearn for the format to return, even if there is some lingering nostalgia for the disks. As it turns out, though, there is still hardware that relies on floppies – namely, the Boeing 747-400, as The Register reports.

The news comes from the work of Pen Test Partners, who recently inspected a 747 being retired as a result of the coronavirus pandemic. The floppy disks are used to load navigational databases which need to be updated regularly, every 28 days. Engineers responsible for loading updates must perform the process manually on the ground.

Efforts have been made in some areas to replace the disks with more modern technology. As Aviation Today covered in 2014, legacy aircraft often require updates involving up to eight floppy disks, leading to slow updates that can cause flight delays. As anyone familiar with the reliability of floppy media knows, it only takes one bad disk to ruin everything. While retrofits are possible, it’s more likely that airlines will simply stick with the technology until the legacy airplanes are retired. Certifying new hardware for flight is a major cost that is difficult to justify when the current system still works.

Floppies continue to cling to relevance, even if for most of us it’s simply as the save icon. We’ve also seen floppies used as an even more inefficient method of data entry. It turns out you can even fit an entire podcast on one, too!

Acoustic Camera Uses Many, Many Microphones

August 10, 2020 by Lewin Day 53 Comments

If you’re a human or other animal with two ears, you’ll probably find great utility in your ability to identify the direction of sounds in the world around you. Of course, this is really just a minimal starting point for such abilities. When [John Duffy] set out to build his acoustic camera, he chose to use ninety-six microphones to get the job done.

The acoustic camera works by having an array of microphones laid out in a prescribed grid. By measuring the timing and phase differences of signals appearing at each microphone, it’s possible to determine the location of sound sources in front of the array. The more microphones, the better the data.

[John] goes into detail as to how the project was achieved on the project blog. Outlining such struggles as assembly issues, he also shares information about how to effectively debug the array, and just how to effectively work with so many microphones at once. Particularly impressive is the video of [John] using the device to track a sound to its source. This technology has potential applications in industry for determining the location of compressed air leaks, for example.

Overall, it’s a university research project done right, with a great writeup of the final results. [John]’s project would serve well as a jumping off point for anyone trying to build something similar. Phased array techniques work in RF, too, as this MIT project demonstrates. Video after the break.

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Talking Head Teaches Laplace Transform

August 9, 2020 by Al Williams 25 Comments

Most people who deal with electronics have heard of the Fourier transform. That mathematical process makes it possible for computers to analyze sound, video, and it also offers critical math insights for tasks ranging from pattern matching to frequency synthesis. The Laplace transform is less familiar, even though it is a generalization of the Fourier transform. [Steve Bruntun] has a good explanation of the math behind the Laplace transform in a recent video that you can see below.

There are many applications for the Laplace transform, including transforming types of differential equations. This comes up often in electronics where you have time-varying components like inductors and capacitors. Instead of having to solve a differential equation, you can perform a Laplace, solve using common algebra, and then do a reverse transform to get the right answer. This is similar to how logarithms can take a harder problem — multiplication — and change it into a simpler addition problem, but on a much larger scale.

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