OpenSCAD handles the Math in 3D Printed Holder for Magnetic Spheres

Off-the-shelf components are great; the world and our work simply wouldn’t be the same without. But one of the constraints is that one has to design around them, and that’s what led [Antonio Ospite] to create a parametric design in OpenSCAD for a 3D printed holder which snugly fits a number of magnetic spheres around its diameter.

If that sounds a bit esoteric, it will become much clearer in the context of [Antonio]’s earlier work in making a DIY rotary encoder out of a ring of magnetic spheres. He found that such a ring in front of two Hall effect …read more

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Low-Quality Capacitors Turned Into High-Quality Temperature Sensors

When life hands you a bunch of crummy capacitors, what do you do? Make a whole bunch of temperature sensors, apparently.

The less-than-stellar caps in question came to [pyromaniac303] by way of one of those all-in-one assortment kits we so love to buy. Stocked with capacitors of many values, kits like these are great to have around, especially when they’ve got high-quality components in them. But not all ceramic caps are created equal, and [pyromaniac303] was determined not to let the lesser-quality units go to waste. A quick look at the data sheets revealed that the caps with the Y5V …read more

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An Achievable Underwater Camera

We are surrounded by sensors for all forms of environmental measurement, and a casual browse through an electronics catalogue can see an experimenter tooled up with the whole array for a relatively small outlay. When the environment in question is not the still air of your bench but the turbulence, sand, grit, and mud of a sea floor, that pile of sensors becomes rather useless. [Ellie T] has been addressing this problem as part of the study of hypoxia in marine life, and part of her solution is to create an underwater camera by encasing a Raspberry Pi Zero W …read more

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Don’t Forget Your Mints When Using This Synthesizer

While synthesizers in the music world are incredibly common, they’re not all keyboard-based instruments as you might be imagining. Especially if you’re trying to get a specific feel or sound from a synthesizer in order to mimic a real instrument, there might be a better style synth that you can use. One of these types is the breath controller, a synthesizer specifically built to mimic the sound of wind instruments using the actual breath from a physical person. Available breath controllers can be pricey, though, so [Andrey] built his own.

To build the synthesizer, [Andrey] used a melodica hose and …read more

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PTPM Energy Scavenger Aims for Maintenance-Free Sensor Nodes

[Mile]’s PTPM Energy Scavenger takes the scavenging idea seriously and is designed to gather not only solar power but also energy from temperature differentials, vibrations, and magnetic induction. The idea is to make wireless sensor nodes that can be self-powered and require minimal maintenance. There’s more to the idea than simply doing away with batteries; if the devices are rugged and don’t need maintenance, they can be installed in locations that would otherwise be impractical or awkward. [Mile] says that goal is to reduce the most costly part of any supply chain: human labor.

The prototype is working well with …read more

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Changing Color Under Pressure

When you saw the picture for this article, did you think of a peacock’s feather? These fibers are not harvested from birds, and in fact, the colors come from transparent rubber. As with peacock feathers, they come from the way light reflects off layers of differing materials, this is known as optical interference, and it is the same effect seen on oil slicks. The benefit to using transparent rubber is that the final product is flexible and when drawn, the interference shifts. In short, they change color when stretched.

Most of the sensors we see and feature are electromechanical, which …read more

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Smart Citizen Opens Eyes and Ears in Barcelona

More often than not, our coverage of projects here at Hackaday tends to be one-off sort of thing. We find something interesting, write it up for our beloved readers, and keep it moving. There’s an unending world of hacks and creations out there, and not a lot of time to cover them all. Still, it’s nice when we occasionally see a project we’ve previously covered “out in the wild” so to speak. A reminder that, while a project’s time on the Hackaday front page might be fleeting, their journey is far from finished.

A perfect example can be found in …read more

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Monitoring Air Quality, One Sleepy Meeting At A Time

To those of us in the corporate world, the conference room is where hope goes to die. Crammed into a space too small for the number of invitees, the room soon glows with radiated body heat and the aromas of humans as the time from their last shower gradually increases. To say it’s not a recipe for productivity is an understatement at best.

Having suffered through too many of these soporific situations, [Charles Ouweland] took matters into his own hands and built this portable air quality meter for meetings. With an OLED display on top and sensors inside, it displays …read more

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Tiny $25 Spectrometer Aims to Identify Materials with Ease

Reflectance spectrometers work on a simple principle: different things reflect different wavelengths in different amounts, and because similar materials do this similarly, the measurements can be used as a kind of fingerprint or signature. By measuring how much of which wavelengths get absorbed or reflected by a thing and comparing to other signatures, it’s possible to identify what that thing is made of. This process depends heavily on how accurately measurements can be made, so the sensors are an important part.

[Kris Winer] aims to make this happen with the Compact, $25 Spectrometer entry for The 2018 Hackaday Prize. The …read more

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Headlight Mod For An Audi A3

If you have a car that is getting on in years, it may be missing some of the latest frills and features that the latest models sport. [Muris] has a slightly dated Audi A3 8P which did not have an AUTO setting for the headlights. In the newer models, this feature turns on the headlights when the ambient light falls below a threshold level (overcast conditions or when going through a tunnel), or when the windshield wipers are turned on. The light sensor is integrated behind the rear view mirror in a special mount, requiring an expensive windshield upgrade if …read more

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