Lo-Fi Tchaikovsky

[Kevin] over at Simple DIY ElectroMusic Projects recently upgraded his Lo-Fi Orchestra. To celebrate his 400th blog post, he programmed it to play Tchaikovsky’s 1812 Overture. Two Arduino Nanos, four Arduino Unos, four Raspberry Pi Picos, and one Raspberry Pi have joined the Lo-Fi Orchestra this year, conducted by a new Pico MIDI Splitter. Changes were made in every section of the orchestra except percussion. We are delighted that the Pringles tom and plastic tub bass drums remain, not to mention the usual assortment of cheap mixers, amps, and speakers.

Tchaikovsky’s score famously calls for some “instruments” not found in the typical orchestra — a battery of cannon and a carillon, for example. Therefore [Kevin] had to supplement the Lo-Fi Orchestra for this performance with extras — a JQ6500 MP3 module on clash cymbals, a bare metal MiniDexed Raspberry Pi playing the carillon, and a MCP4725 with a Lots-of-LEDs shield firing off cannon and fireworks, respectively.

Although slightly disappointed that the MCP4725 beat out Mr. Fireworks in the auditions, we do like the result. [Kevin] reports that the latest version is much more reliable and predictable, having eliminated various MIDI faults and electrical noise. It presents a stable platform for future musical presentations, a kind of on-demand Lo-Fi Orchestra jukebox, as he describes it. A detailed review of all the changes can be found in his explanatory blog post. Check out an earlier performance of Holst’s The Planets suite from our coverage back in 2021.

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Solar Cells As Art Form

When most of us approach a project, we have a certain problem to solve. 3D printing, microcontrollers, batteries, and all kinds of technologies are usually tools to accomplish some task. This is not necessarily true in the art world, though, where the intrinsic nature of these tools can be explored for their own sake rather than as a means to an end. The latest one that came across our desk is this light-powered sound generator.

The art piece looks a bit like a mobile with rotating arms, holding various small solar cells each connected to a speaker. As the arms pivot, the light falling on the cells changes which drives a specially-designed circuit connected to a speaker. The circuit acts as an oscillator, passing the changing voltage from the cell through various capacitors and transistors to produce changing tones in the speaker.

The effect of the rotating solar panels is not only oscillations from the speakers as the light changes, but oscillations in the sound of the speakers as they rotate towards and away from the observer. It’s a unique project and perfect for the art show it was in. It’s also not the only sound-focused art installation we’ve ever seen before, be sure to check out this one based on an ESP32.

Adding A Battery To Extend Speaker Life

Perhaps the weakest point in modern electronics when it comes to user servicability is the lifecycle of the batteries included from the manufacturer. Without easily replaceable batteries, many consumer goods end up in the landfill when they’re otherwise working perfectly. If you’d like to get more out of your devices than the manufacturer intends, you might have to go to great lengths like [Théo] did with his JBL speaker.

This was a Bluetooth device produced by JBL nearly a decade ago, and while the original device boasted several hours of battery life, after so many years of service, it was lucky to get a half hour before the battery died. To replace it, [Théo] removed the original battery and extended the case to be able to hold a larger cell phone battery. He also decided to use the original battery management circuit from the speaker with the new battery after verifying the voltage and chemistry were close enough to the original.

Since the phone battery is a proprietary Samsung device, [Théo] also decided to build a version that uses standard 18650 cells instead, although he prefers the slimmer design with the phone battery for his use case.  Straightforward as this build may be, it does go a long way to demonstrate the principle that if you can’t fix your devices, you don’t really own them.

Pocket Radio Powered By Tiny Microcontroller

Before the days of MP3 players and smartphones, and even before portable CD players, those of us of a certain age remember that our cassette players were about the only way to take music on-the-go. If we were lucky, they also had a built-in radio for when the single tape exhausted both of its sides. Compared to then, it’s much easier to build a portable radio even though cassettes are largely forgotten, as [wagiminator] shows us with this radio design based on an ATtiny.

The build is about as compact as possible, with the aforementioned ATtiny 402/412 as its core, it also makes use of an integrated circuit FM tuner,  an integrated audio amplifier with its own single speaker, and a small OLED display. The unit also boasts its own lithium-polymer battery charger and its user interface consists of only three buttons, plenty for browsing radio stations and controlling volume.

The entire build fits easily in the palm of a hand and is quite capable for a mobile radio, plus all of the schematics and code is available on the project page. While it doesn’t include AM capability, just the fact that FM is this accessible nowadays when a few decades ago it was cutting-edge technology is quite remarkable. If you’re looking for an even smaller FM receiver without some of the bells and whistles of this one, take a look at this project too.

Generate Fully Parametric, 3D-Printable Speaker Enclosures

Having the right speaker enclosure can make a big difference to sound quality, so it’s no surprise that customizable ones are a common project for those who treat sound seriously. In that vein, [zx82net]’s Universal Speaker Box aims to give one everything they need to craft the perfect enclosure.

The parts can be 3D-printed, but the design ensures that the front and back panels are flat, so one can use wood or some other material for those depending on preference and appearance. The assembly is screwed together using six M3 bolts per side with optional heat-set inserts, but it’s entirely possible to simply glue the unit together if preferred.

One thing that makes this design a bit more broadly useful is that [zx82net] not only provides the parametric design file for Fusion360, but also includes STEP format CAD files, and a small number of pre-configured assemblies for a few commonly available speaker drivers: the Dayton Audio DMA70-4, ND91-4, and the TCP115-4. Not enough for you? Check out [zx82net]’s collection of ready-to-rock enclosures in a variety of designs and configurations; there’s bound to be something to appeal to just about anyone.

[via Reddit]

Arduino Orchestra Plays The Planets Suite

We’ve seen a great many Arduino synthesizer projects over the years. We love to see a single Arduino bleeping out some monophonic notes. From there, many hackers catch the bug and the sky is truly the limit. [Kevin] is one such hacker who now has an Arduino orchestra capable of playing all seven movements of Gustav Holst’s Planets Suite.

The performers are not human beings with expensive instruments, but simple microcontrollers running code hewn by [Kevin’s] own fingertips. The full orchestra consists of 11 Arduino Nanos, 6 Arduino Unos, 1 Arduino Pro Mini, 1 Adafruit Feather 32u4, and finally, a Raspberry Pi.

Different synths handle different parts of the performance. There are General MIDI synths on harp and bass, an FM synth handling wind and horn sections, and a bunch of relays and servos serving as the percussive section. The whole orchestra comes together to do a remarkable, yet lo-fi, rendition of the whole orchestral work.

While it’s unlikely to win any classical music awards, it’s a charming recreation of a classical piece and it’s all the more interesting coming from so many disparate parts working together. It’s an entirely different experience than simply listening to a MIDI track playing on a set of headphones.

We’d love to see some kind of hacker convention run a contest for the best hardware orchestra. It could become a kind of demoscene contest all its own. In the meantime, scope one of [Kevin’s] earlier projects on the way to this one – 12 Arduinos singing Star Wars tracks all together. Video after the break.

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A macro keypad making music.

Meet The Marvelous Macro Music Maker

Do you kind of want a macropad, but aren’t sure that you would use it? Hackaday alum [Jeremy Cook] is now making and selling the JC Pro Macro on Tindie, which is exactly what it sounds like — a Pro Micro-based macro keypad with an OLED screen and a rotary encoder. In the video below, [Jeremy] shows how he made it into a music maker by adding a speaker and a small solenoid that does percussion, all while retaining the original macro pad functionality.

[Jeremy]’s original idea for a drum was to have a servo seesawing a chopstick back and forth on the table as one might nervously twiddle a pencil. That didn’t work out so well, so he switched to the solenoid and printed a thing to hold it upright, and we absolutely love it. The drum is controlled with the rotary encoder: push to turn the beat on or off and crank it to change the BPM.

To make it easier to connect up the solenoid and speaker, [Jeremy] had a little I²C helper board fabricated. There’s one SVG connection and another with power and ground swapped in the event it is needed. If you’re interested in the JC Pro Macro, you can pick it up in various forms over on Tindie. Of course, you might want to wait for version 2, which is coming to Kickstarter in October.

There are many ways to make a macro keyboard. Here’s one that also takes gesture input.

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