[Yannick], aka [Gigawipf] brings us this (mostly) musical delicacy: a 3D-printed siren that’s driven by a brushless quadcopter motor, and capable of playing (mostly) any music that you’ve got the MIDI score for. This is a fantastic quickie project for any of you out there with a busted quad, or even some spare parts, and a 3D printer. Despite the apparent level of difficulty, this would actually be a great quickie weekend build.
We aren’t sure this technically qualifies as music synthesis, but what else do you call a computer playing music? In this case, the computer is a Teensy, and the music comes from a common classroom instrument: a plastic recorder. The mistaken “flute” label comes from the original project. The contraption uses solenoids to operate 3D printed “fingers” and an air pump — this is much easier with a recorder since (unlike a flute) it just needs reasonable air pressure to generate sound.
A Teensy 3.2 programmed using the Teensyduino IDE drives the solenoids. The board reads MIDI command sent over USB from a PC and translates them into the commands for this excellent driver board. It connects TIP31C transistors, along with flyback diodes, to the solenoids via a terminal strip.
On the PC, a program called Ableton sends the MIDI messages to the Teensy. MIDI message have three parts: one sets the message type and channel, another sets the velocity, and one sets the pitch. The code here only looks at the pitch.
This is one of those projects that would be a lot harder without a 3D printer. There are other ways to actuate the finger holes, but being able to make an exact-fitting bracket is very useful. Alas, we couldn’t find a video demo. If you know of one, please drop the link in the comments below.
A lot of classic synthesizers rely on analog control voltages to vary parameters; this is a problem for the modern musician who may want to integrate such hardware with a MIDI setup. For just this problem, [little-scale] has built a MIDI-controllable DAC for generating control voltages.
It’s a simple enough build – a Teensy 2 is used to speak USB MIDI to a laptop. This allows the DAC to be used with just about any modern MIDI capable software. The Teensy then controls a Microchip MCP4922 over SPI to generate the requisite control voltages. [little-scale]’s video covers the basic assembly of the hardware on a breadboard, and goes on to demonstrate its use with a performance using the MIDI DAC to control a Moog Mother 32 synth. [little-scale] has also made the code available, making it easy to spin up your own.
We can see this project being indispensable to electronic musicians working with banks of modular synths, making it much easier to tie them in with automation in their DAW of choice. This isn’t the first MIDI interfacing hack we’ve seen either – check out this setup to interface an iPad to guitar pedals.
Since the 1980s, MIDI has been a great way to send data between electronic musical instruments. Beginning as a modified serial interface running through optoisolaters and DIN sockets, these days, your hardware is more likely to carry its MIDI data over USB instead. This is great if you want to hook up to a computer without a cumbersome interface, but not so great when you want to connect a bunch of instruments to each other.
The Roland Integra 7 is a rack mount synthesizer with classic MIDI ports. [adriangin] wanted to control the synthesizer over MIDI, but their Casio keyboard only had MIDI over USB available. To get around this, [adriangin] set out to add a standard MIDI Out port to the Casio PX410R.
In large churches that still use real bells in their bell towers, a large number of them ring bells using a method called full circle ringing. In order to get the bells to sound at exactly the right time, the bells are rung by swinging the entire bell in an almost complete 360-degree arc. This helps to mitigate the fact that often times, the bells weigh more than the person ringing the bells. However, if you don’t have access to a belfry, you can practice ringing bells using this method with your own full circle bell simulator.
The frame for the bell was built from some leftover aluminum extrusion and allows the bell to easily swing on some old skateboard bearings. The mechanism is electrically controlled, too, using a hall effect sensor and a USB adapter so that it can be interfaced with a computer running a virtual bell ringing suite. Once some timing issues are worked out, the bell is all set up and ready to practice ringing changes.
If you’re as fascinated as we are to find that there are entire software suites available to simulate bell ringing, and an entire culture built around something that most of us, perhaps, wouldn’t have given a second thought to outside of walking past a church on a Sunday, there have been a surprising number of other bell-related projects over the years. Bells have been given MIDI interfaces and robotified, and other church instruments like a pipe organ have been created almost from scratch.
Ever since Jimi Hendrix brought guitar distortion to the forefront of rock and roll, pedals to control the distortion have been a standard piece of equipment for almost every guitarist. Now, there are individual analog pedals for each effect or even digital pedals that have banks of effects programmed in. Distortion is just one of many effects, and if you’ve built your own set of pedals for each of these, you might end up with something like [Brian]: a modular guitar pedal rack.
Taking inspiration from modular synthesizers, [Brian] built a rack out of wood to house the pedal modules. The rack uses 16U rack rails as a standard, with 3U Eurorack brackets. It looks like there’s space for 16 custom-built effects pedals to fit into the rack, and [Brian] can switch them out at will with a foot switch. Everything is tied together with MIDI and is programmed in Helix. The end result looks very polished, and helped [Brian] eliminate his rat’s nest of cables that was lying around before he built his effects rack.
MIDI is an extremely useful protocol for musicians and, despite being around since the ’80s, doesn’t show any signs of slowing down. If you want to get into it yourself, there are all kinds of ways that you can explore the studio space, even if you play an instrument that doesn’t typically use MIDI.
If you are a musician and you are also a Hackaday reader, there’s a good chance you’ll own at least one MIDI instrument. A synthesizer of some description, maybe a keyboard, or perhaps a drum machine. A pipe organ? Probably not.
If you answer to the name of [Wendell Kapustiak] though, you’d say yes to that question. He’s built himself a beautiful pipe organ from scratch, with hand-tuned wooden pipes, and for a modern touch he’s made it MIDI controlled. An Arduino Due sends its commands to a set of solenoid drivers, the solenoids then control the air flow from his wind chest through a set of plastic tubes to his organ pipes. Air supply comes from a shop vac in a sound-insulated box, with a pressure regulating chamber. The result is not perfect, he believes that the pipes are too close together and this somehow makes them difficult to tune, but to an outsider’s eye it’s a pretty impressive instrument.
[Wendell] is both a skilled and prolific maker, and his blog is rather a good read. The organ project is spread over a few years, so to get the full picture it is best to read his previous posts on the subject as well as the one first linked. He recounts his early experiments as well as giving us details of the electronics and the pipes. He’s put up a video showing the completed instrument which you can see below the break, and another more recently showing a recent one-LED-per-note modification.
Continue reading “A Pipe Organ For The MIDI Generation”