Tiny PCB PiezoPiano Plays Just One Octave

March 19, 2023 by Lewin Day 11 Comments

Grand pianos are beautiful instruments, but take up altogether too much space. Upright pianos are smaller, but still fairly hefty. When it comes to the PiezoPiano, though, we suspect nobody could complain about its diminutive size. It’s a tiny thing with just one buzzy little octave for your playing pleasure.

The PiezoPiano is a single PCB device with a ATmega4809 running the show. It has eight buttons and eight piezo transducers that give you just one octave’s range on the keyboard. Truth be told, that’s only in one scale; you’re not getting the whole twelve tones of flats and sharps included. And, when we say keyboard, we really mean “tactile buttons.” You get the drift. It’s all assembled in a cute enclosure mimicking the shape of a real grand piano.

Fundamentally, it’s a cute little musical desktoy that reminds us greatly of the Stylophone. Impressively, though, those eight buzzers mean it has eight-note polyphony. That’s nothing to sniff at compared to all the monophonic synths out there. It’s also available on Tindie if you’d like to buy a kit off the shelf. Video after the break.

Continue reading “Tiny PCB PiezoPiano Plays Just One Octave” →

Lo-Fi Fun: Beer Can Microphones

December 27, 2022 by Kristina Panos 16 Comments

Sometimes, you just need an easy win, right? This is one of those projects. A couple months back, I was looking at my guitars and guitar accessories and thought, it is finally time to do something with the neck I’ve had lying around for years. In trying to decide a suitable body for the slapdash guitar I was about to build, I found myself at a tractor supply store for LEGO-related reasons. (Where else are you going to get a bunch of egg cartons without eating a bunch of eggs?) I noticed that they happened to also stock ammo boxes. Bam! It’s sturdy, it opens easily, and it’s (very) roughly guitar body shaped. I happily picked one up and started scheming on the way home.

Having never built a cigar box guitar before and being of a certain vintage, I’m inclined to turn to books instead of the Internet, so I stocked up from the library. Among my early choices was Making Poor Man’s Guitars by Shane Speal, who is widely considered to be the guru on the subject. In flipping through the book, I noticed the beer can microphone project and was immediately taken by the aesthetic of some cool old 70s beer can with a 1/4″ instrument jack on the bottom, just asking for some dirty blues to be belted into it. I had to build one. Or twelve.

Continue reading “Lo-Fi Fun: Beer Can Microphones” →

Hackaday Prize 2022: Ultratower Is A Powerful Gardening Vertical

November 4, 2022 by Kristina Panos 29 Comments

The more people we have on this planet, the more food we need. Naturally, this extends to water, another precious resource that generally plays a part in farming and food production. And honestly, we’d probably all eat a little better if it were really easy to grow healthy things like spinach. Well, that excuse doesn’t work anymore, thanks to [J Gleyzes]’ Ultratower. It’s a simple-to-use hydroponic tower that uses recycled mist to water plants, ultimately saving water in the process.

The ‘ultra’ part is a function of the way mist is created. In this case, it’s done with three piezoelectric disks mounted under a tank in the top of the PVC tube. Stick up to twelve plants in the little cubbies, and their roots will grow down the inside, where they’ll receive a fine shower of water at your command. Water that runs off the roots collects in a small tank at the bottom, where a pump starts the process over again.

At first, [J Gleyzes] had trouble with the piezo disks — using 1.7MHz disks created too much heat, warming the water up to nearly 40°C (104°F). Since cooking the spinach prematurely would be bad, they experimented with other values, finally landing on 108KHz. Be sure to check out the video after the break.

Continue reading “Hackaday Prize 2022: Ultratower Is A Powerful Gardening Vertical” →

Simple Setup Answers Complex Question On The Physics Of Solids

February 1, 2022 by Dan Maloney 17 Comments

Thought experiments can be extremely powerful; after all, pretty much everything that [Einstein] came up with was based on thought experiments. But when a thought experiment turns into a real experiment, that’s when things can get really interesting, and where unexpected insights crop up.

Take [AlphaPhoenix]’s simple question: “Are solid objects really solid?” On the face of it, this seems like a silly and trivial question, but the thought experiment he presents reveals more. He posits that pushing on one end of a solid metal rod a meter or so in length will result in motion at the other end of the rod pretty much instantly. But what if we scale that rod up considerably — say, to one light-second in length. Is a displacement at one end of the rob instantly apparent at the other end? It’s a bit of a mind-boggler.

To answer the question, [AlphaPhoneix] set up a simple experiment with the aforementioned steel rod — the shorter one, of course. The test setup was pretty clever: a piezoelectric sensor at one end of the bar, and a hammer wired to a battery at the other end, to sense when the hammer made contact with the bar. Both sensors were connected to an oscilloscope to set up to capture the pulses and measure the time. It turned out that the test setup was quite a challenge to get right, and troubleshooting the rig took him down a rabbit hole that was just as interesting as answering the original question. We won’t spoil the ending, but suffice it to say we were pleased that our first instinct turned out to be correct, even if for the wrong reasons.

If you haven’t checked out [AlphaPhoenix] yet, you really should. With a doctorate in material science, he’s got an interesting outlook on things, like calculating pi using raindrops or keeping the “ultra” in ultra-high vacuum. Continue reading “Simple Setup Answers Complex Question On The Physics Of Solids” →

A kinetic art installation with many metal parts

Kinetic Art Installation Brings All The World’s Lightning To One Place

January 27, 2022 by Robin Kearey 2 Comments

Lightning is a force to be reckoned with: ever since ancient times, humans have been in awe of the lethal power of lightning strikes and the deafening roar of thunder. Quite reasonably, they ascribed these events to acts of angry gods; today, modern science provides a more down-to-earth explanation of the physics involved, and a world-wide network of sensors generates a real-time record of lightning strikes around the globe.

[Dmitry Morozov]’s latest kinetic art installation called Adad is driven by this stream of data. Named after a Mesopotamian god of thunder, it consists of a set of arms that suddenly jerk upwards when a lightning strike is detected anywhere in the world. When an arm falls down again, it strikes a piezo crystal, which generates an electric charge that triggers a bright flash of light as well as a sound effect. Those crystals are pieces of potassium sodium tartrate (also known as Rochelle salt) and were grown specifically for this project. They are housed in plexiglass holders which also provide electrical connections.

Adad‘s spider-like design, its eerie sounds as well as the sudden pops and flashes make this a rather unsettling yet beautiful display of Nature’s violence. And it’s a piece of beauty from an engineering point of view as well: sleek aluminium tubes, servo-driven motion and those transparent crystal holders, all controlled by an Arduino that receives live lightning data through an internet connection.

We’ve seen several types of lightning detectors, usually based on a standard radio receiver or a specialized chip. If you’re interested in growing your own piezo crystals, we’ve covered that too. Continue reading “Kinetic Art Installation Brings All The World’s Lightning To One Place” →

Nicolas Bras and his homemade musical instruments

Hacked Set Of Instruments Saves Musician’s Gigs

October 8, 2021 by Dan Maloney 19 Comments

Most of the horror stories you hear about air travel seem to center around luggage. Airlines do an admirable job of getting people safely to their destinations, but checked baggage is a bit of a crapshoot — it could be there when you land, it could end up taking the scenic route, or it could just plain disappear. That’s bad enough when it contains your clothes, but when it contains your livelihood? Talk about stress!

This was the position musician [Nicolas Bras] found himself in after a recent trip. [Nicolas] was heading for a gig, but thanks to Brussels Airlines, his collection of musical instruments went somewhere else. There was nothing he could do to salvage that evening’s gig, but he needed to think about later engagements. Thankfully, [Nicolas] specializes in DIY musical instruments, made mostly with PVC tubes and salvaged parts from commercial instruments, so the solution to his problem was completely in his hands.

Fair warning to musical instrument aficionados — harvest the neck from a broken ukelele is pretty gruesome stuff. Attached to a piece of pallet wood and equipped with piezo pickups, the neck became part of a bizarre yet fascinating hybrid string instrument. A selection of improvised wind instruments came next, made from PVC pipes and sounding equally amazing; we especially liked the bass chromojara, sort of a flute with a didgeridoo sound to it. The bicycle pump beatbox was genius too, and really showed that music is less about the fanciness of your gear and more about the desire — and talent — to make it with whatever comes to hand.

Here’s hoping that [Nicolas] is eventually reunited with his gear, but hats off to him in the meantime for hacking up replacements. And if he looks familiar, that’s because we’ve seen some of his work before, like his sympathetic nail violin and “Popcorn” played on PVC pipes.

Continue reading “Hacked Set Of Instruments Saves Musician’s Gigs” →

Piezo Pickup Makes Wax Records Easy To Digitize

June 23, 2021 by Dan Maloney 27 Comments

Sound recording and playback have come a long way in the last century or so, but it’s fair to say there’s still a lot of interesting stuff locked away on old recordings. Not having a way to play it back is partly to blame; finding an antique phonograph that plays old-timey cylinder recordings is pretty hard. But even then, how do you digitize the output of these fragile, scratchy old recordings?

As it happens, [Jan Derogee] is in a position to answer these questions, with an antique phonograph and a bunch of Edison-style wax cylinders with voices and music from a bygone era locked away on them. It would be easy enough to just use the “reproducer” he previously built and set up a microphone to record the sound directly from the phonograph’s trumpet, but [Jan] decided to engineer a better solution. By adding the piezo element from an electronic greeting card to his reproducer, potted with liberal quantities of epoxy and padded with cotton, the piezo pickup was attached to the phonograph arm in place of the original stylus and trumpet. The signal from the piezo element was strong enough to require a shunt resistor, allowing it to be plugged directly into the audio input jack on a computer. From there it’s just an Audacity exercise, plus dealing with the occasional skipped groove.

We appreciate [Jan]’s effort to preserve these recordings, as well as the chance to hear some voices from the past. We’re actually surprised the recording sound as good as they do after all this time — they must have been well cared for.

Continue reading “Piezo Pickup Makes Wax Records Easy To Digitize” →