Print Your Own Wireless 2.1 Speaker System

April 29, 2021 by 17 Comments

Buying a set of stylish bookshelf speakers is a perfectly reasonable thing to do, and remains legal in most free countries around the world. However, if you really want to impress with a pretty pair to crank out your tunes, you might consider designing and printing your own. [EH_Design] did just that with a stylish 2.1 Bluetooth audio system.

The 2.1 designation refers to the use of two stereo channels plus a subwoofer. It’s a popular setup as human perception means it’s not as necessary to have stereo imaging for low frequency content. The build uses a Texas Instruments TPA3116D2 Class D amplifier with a Bluetooth input, with the efficient design allowing the build to be more compact without the need for as much heat sinking. A 24 V supply delivering up to 3 A is specified, providing plenty of volume when needed. The speakers themselves consist of 3″ drivers mounted in attractive 3D-printed shells, with the “subwoofer” consisting of a pair of 5″ woofers paired up in a special isobaric enclosure that enables a smaller volume to acoustically act like one double the size.

The result is a futuristic-looking set of bookshelf speakers that remind us of some of the fancier high-end sets often seen in hi-fi magazines. Of course, if 3D printing enclosures isn’t enough for you, you could always consider 3D printing the actual speaker driver itself. When you do, let us know how it goes!

 

RC Ekranoplan Uses LIDAR To Fly In Ground Effect

April 29, 2021 by 33 Comments

Ekranoplans are a curious class of vehicle; most well known for several Soviet craft designed to operate at sea, flying just above the waves in ground effect. [rctestflight] had accidentally come across the ground effect flight regime himself years ago, and decided it was time to build an ekranoplan of his own.

I want to see little ekranoplans in at least three top 10 pop film clips by summer’s end. Please and thank you.

While ground-effect flight can be quite stable for a heavy, human-scale craft, the smaller RC version suffered more from minor perturbations from the wind and such. Thus, a Pixracer autopilot was installed, and combined with a small LIDAR device to accurately measure altitude above the ground. With some custom tweaks to the Ardupilot firmware, the craft was able to cleanly fly along barely a foot off the ground.

The final effect is almost mesmerizing; it appears as if the craft is hovering via some heretofore unknown technology rather than just flying in the usual sense. It’s still sensitive to breezes and sudden drops in the terrain lead to a temporary escape from the ground effect region, but the effect is nonetheless impressive. It’s a nerve wracking video at times, though, with quite a few near misses with traffic and children. Regardless of the nature of your experimental craft, be cognisant of your surroundings. We’ve seen [rctestflight]’s Ardupilot experiments before, too. Video after the break.

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Measuring An Atom

April 28, 2021 by 17 Comments

Do you need a well-equipped lab to measure the size of an atom (German, machine translation)? According to [stoppi], no. You need sunflower oil, some bear moss spores, and a bit of gasoline. You’ll also need some common things like a syringe, a baking sheet, and a jar. You can see the whole process in the video below. The measurement isn’t really for a specific atom, but it is an average for a lipid molecule, which is still impressive.

You essentially measure the diameter of an oil drop spread over water. Since the oil is mostly oleic acid, the height of the layer is known as 167 atoms. After that, it is some simple measurements and math to get the height and find the average atom height.

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Open Source Pizza Compass Will Show You The Way

April 28, 2021 by 18 Comments

In Pirates of the Caribbean, Captain Jack Sparrow has an enchanted compass that points to what the holder wants most in life. The Pizza Compass created by [Joe Grand] is basically the same thing, except it’s powered by a Particle Boron instead of a voodoo spell. Though depending on who’s holding the thing, we imagine they’d even point in the same direction.

[Joe] was tasked by Wired to design and produce the Pizza Compass in three weeks, a process which was documented in the video below. Being the Badgelife luminary that he is, the final product looks far more attractive than it has any business being. In addition to the Particle Boron that slots in on the back of the handheld PCB, there’s a GlobalTop PA6H GPS module, a LSM303DLHC compass, and eight NeoPixels that correspond to the points on the silkscreen compass.

From prototype to final product.

Using the device is simple, just press the button and then walk around trying to keep the top-most LED lit. Behind the scenes, the Boron is pulling down the coordinates of the closest pizza place as reported by Google’s API, and comparing that to the user’s current GPS location. In practice that means the Pizza Compass isn’t concerned with nuances like streets or buildings, so its up to the user to figure out how best to stay on the desired heading. So rather than just following some turn-by-turn directions, there’s some proper navigation involved if you want that fresh slice.

If you don’t like pizza, you could reprogram the compass to point to whatever quest-worthy resource you wish. As explained at the end of the video, [Joe] wanted this to be an open source project so it could easily be adapted for different tasks by the community. Though honestly, it’s pretty weird if you don’t like pizza.

We’ve actually covered a very similar device in the past that would point the user to the closest White Castle or Five Guys, but with all due respect to that project, the Pizza Compass is in another league. When you’ve got the talent and experience of [Joe Grand] on the team, even the most mundane of gadgets ends up looking like a piece of art.

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Alone, But Not Lonely: Remembering Astronaut Michael Collins

April 28, 2021 by 21 Comments

With many of the achievements of the Space Race now more than half a century behind us, it’s no wonder that we’re steadily losing the men who rode the rockets of the Mercury, Gemini, and Apollo programs into space. They were all very much in their primes at the time, but no matter what you’ve accomplished in life, even if it includes a trip to the Moon, time eventually catches up to you.

Still, it was quite a shock to learn today that astronaut Michael Collins passed away today at the age of 90. Collins made his trip to the Moon aboard Apollo 11, the mission which would see his crewmates Neil Armstrong and Edwin “Buzz” Aldrin descend to the surface in the Lunar Module Eagle and take the historic first steps on its surface in July of 1969.

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Winners Of Hackaday’s Earth Day Contest: Solar LIC, Auto-Return Parafoil, & Water Flowmeter

April 28, 2021 by 10 Comments

Winners have just been announced for Hackaday’s Earth Day Challenge. We were on the lookout for projects that raise awareness of environmental issues and are happy to celebrate three top winners. Each have won a $200 shopping spree from Digi-Key who sponsored this contest.

Pictured above is the Open Flow Meter by [Eben]. The build includes sensors that are submerged into a river or stream to gauge the speed at which the water is moving. It uses a commodity plumbing flow volume sensor to help reduce costs, adding an Arduino and touch screen for reading the sensors and providing a UI to the user.

High-altitude balloons are used for air quality and weather sensing. To make those sensor packages more reusable, [Hadji Yohan] has been working on a parachute recovery system that automatically returns to a set GPS point. It’s a parafoil with auto-pilot!

Power harvesting is a fascinating and tricky game. To help ease the transition away from batteries, [Jasper Sikken] developed a solar harvesting module that charges a Lithium Ion Capacitor (LIC) from a very small solar panel. Based around a 100 uF 30 F capacitor, it uses an AEM10941 energy harvesting chip which includes Maximum Power Point Tracking (MPPT) to utilize the solar panel as efficiently as possible. The fully charged module can output regulated 2.2 V and is aimed at distributed sensor packages that can be run without any battery at all.

Congratulations to these three top finishers, as well as the b-parasite capacitive soil moisture sensor which was named as a runner up in the contest. There were 72 entries in this challenge so don’t forget to take a look at the entire field, and leave a comment on the ones that catch your eye to let them know we all love seeing details of great builds!

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Lamps Double As Secret Surround Sound Speakers

April 28, 2021 by 23 Comments

Combined with today’s massive flat panel displays, a nice surround sound system can provide an extremely immersive environment for watching movies or gaming. But a stumbling block many run into is speaker placement. The front speakers generally just go on either side of the TV, but finding a spot for the rear speakers that’s both visually and acoustically pleasing can be tricky.

Which is why [Peter Waldraff] decided to take a rather unconventional approach and hide his rear surround sound speakers in a pair of functioning table lamps. This not only looks better than leaving the speakers out, but raises them up off the floor and into a better listening position. The whole thing looks very sleek thanks to some clever wiring, to the point that you’d never suspect they were anything other than ordinary lamps.

The trick here is the wooden box located at the apex of the three copper pipes that make up the body of the lamp. [Peter] mounted rows of LEDs to the sides of the box that can be controlled with a switch on the bottom, which provides light in the absence of a traditional light bulb. The unmodified speaker goes inside the box, and connects to the audio wires that were run up one of the pipes.

In the base, the speaker and power wires are bundled together so it appears to be one cable. Since running the power and audio wires together like this could potentially have resulted in an audible hum, [Peter] only ran 12 VDC up through the lamp to the LEDs and used an external “wall wart” transformer. For convenience, he also put a USB charging port in the center of the base.

When speakers or surround sound systems pass our way, it’s usually because some hacker has either made  a set from scratch, or has added some new and improved capabilities to their existing gear. This project may be a bit low-tech compared to some that have graced these pages, but it’s undoubtedly a clever and unexpected solution to the problem, and that’s a hack in our book.

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