If you fly much or work in a loud office, you know that noise-canceling headphones can be a sanity saver. Wouldn’t it be nice if you could just have noise-canceling without the headphones? Apparently, a lot of people think that’s a good idea and funded a project called Muzo. [Electroboom] borrowed one and — mystified how such a device could work — set out to test it. Along the way, in the video below, you can see him do a neat demonstration with two speakers canceling each other in his closet.
Based on [Electroboom’s] tests and the tests from other users, it doesn’t appear that Muzo does much to reduce noise. It might add some noise of its own, but that’s a far cry from what people expected the unit to do.
[Tim] was tired of using his lathe to turn round things. He decided to make a gaming die—something that’s iconically square—out of cylindrical scrap. As it turns out, this is possible to do on a lathe with a three jaw chuck. [Tim] discovered that the bevel on the jaws will hold a cylindrical puck of scrap sideways while he squares off the round sides into faces.
Turning a cube on a lathe looks pretty fiddly, so we applaud [Tim]’s lovely handiwork even more. As you’ll see in the video down below, things were going gangbusters until he went to make the last facing cut. Maybe the tool wasn’t lined up just so, or something was off in the chucking, but the first pass made a bit of a gouge in the stock. Looks like it was easy enough to fix, though. After four 90° turns and facing cuts, he had a nice looking rough cube to work with.
This is a regulation-sized die, so the next step was to trim it down to 16mm³. Then it was time to sand, polish, and add the dots. To lay them out, [Tim] sprayed the cube with layout fluid and scribed unique line patterns on each face. Then he drilled the indentations and filled them in with aluminium black.
It’s easy to become obsessed with music, especially once you start playing. You want to make music everywhere you go, which is completely impractical. Don’t believe me? See how long you can get away with whistling on the subway or drumming your hands on any number of bus surfaces before your fellow passengers revolt. There’s a better way, and that way is portable USB MIDI controllers.
[Johan] wanted a pocket-sized woodwind MIDI controller, but all the existing ones he found were too big and bulky to carry around. With little more than a Teensy and a pressure sensor, he created TeensieWI. It uses the built-in cap sense library to read input from the copper tape keys, generate MIDI messages, and send them over USB or DIN. Another pair of conductive pads on the back allow for octave changes. [Johan] later added a PSP joystick to do pitch bends, modulation, and glide. This is a simple build that creates a versatile instrument.
You don’t actually blow air into the mouthpiece—just let it escape from the sides of your mouth instead. That might take some getting used to if you’ve developed an embouchure. The values are determined by a pressure sensor that uses piezoresistivity to figure out how hard you’re blowing. There’s a default breath response value that can be configured in the settings.
TeensiWI should be easy to replicate or remix into any suitable chassis, though the UV-reactive acrylic looks pretty awesome. [Johan]’s documentation on IO is top-notch and includes a user guide with a fingering chart. For all you take-my-money types out there, [Johan] sells ’em ready to rock on Tindie. Check out the short demo clips after the break.
As more and more drones hit the skies, we are beginning to encounter a modest number of problems that promise to balloon if ignored. 825,000 drones above a quarter-kilo in weight were sold in the U.S. in 2016. The question has become, how do we control all these drones?
Those that work in front of a computer for a living spend most of the time making very little sound. Unless you’re a member of the clicky mechanical keyboard club, your working time is a low-observables time during which people can forget about you. You can make sure you’re not overlooked with this smartphone hotspot presence detector.
[Emilio Ficara]’s quiet work habits resulted in his housemates locking him in sometimes, to his inconvenience. PIR or microwave occupancy sensors might have worked to fix the problem, except that a few flexing fingers aren’t always enough to trigger them. Luckily, [Emilio] is also wisely distrustful of free WiFi, so his phone is always set up as a mobile hotspot, giving him the means to reliably detect his presence. An ATtiny2313 and an ESP-01 do the business of polling for the SSID of his phone and blinking a bright blue LED by his door for his housemates. It’s not perfect, of course; it could easily be spoofed by anyone else who knows his SSID. But simple works for now.
With almost everyone carrying one now, smartphone detection is a good proxy for the presence of a person. But it doesn’t work in every case, so you may want to familiarize yourself with the aforementioned PIR and microwave methods.
Where does your mind jump when you hear the mention of electroshock therapy? The use of electrical current to treat various medical conditions has a long and controversial history. Our fascination with the medical applications of electricity have produced everything from the most alarming of patent medicines to life-saving devices like pacemakers and the Automatic External Defibrillator.
The oldest reference I could find is the use of the torpedo fish to allegedly cure headaches, gout, and so on in 43 CE. Incidentally, Torpedo torpedo is an awesome species name.
Much more recently, there has been interest in transcranial direct current stimulation (tDCS). In essence, it’s a technique by which you pass an electrical current (typically about 2 milliamps) between strategically positioned electrodes on your head. The precise reason to do this is a bit unclear; different journal articles have suggested improvements in cognition, learning, and/or the potential treatment of various diseases.
I think most of us here spend a lot of time studying. The idea that a simple, noninvasive device can accelerate that is very attractive. We’ve covered a few people building their own such devices.
Unfortunately, what we want to be true is irrelevant. Superficially, this looks like a DARPA-funded panacea with no clearly established mechanism of action. Various commercial products are being sold that imply (but as usual, don’t directly state) that tDCS is useful for treating pretty much everything, with ample use of ‘testimonials’.
While tDCS can be prescribed by a physician in some countries to complement a stroke rehabilitation regime, for off-label purposes you may as well just go apply a fish to your face. Let’s dig into the literature and products that are out there and see if we can find the promise hiding amidst the hype.
We’ve talked about TensorFlow before — Google’s deep learning library. Crunching all that data is the province of big computers, not embedded systems, right? Not so fast. [Neil-Tan] and others have been working on uTensor, an implementation that runs on boards that support Mbed-OS 5.6 or higher.
Mbed of course is the embedded framework for ARM, and uTensor requires at least 256K of RAM on the chip and an SD card less than (that’s right; less than) 32 GB. If your board of choice doesn’t already have an SD card slot, you’ll need to add one.
