electronic woodwind/brass instrument? advice?

hey everyone.. im looking to develop an electric blown instrument... im not sure i could really make brass instruments work since a lot of them rely on varying pressure of air.. perhaps if i could create a mouth piece that detected air pressure, perhaps a piezo, or some spring loaded valve..

anyway.. that would be nice.. but id like to focus on the bulk of making this work.. my idea is to use pvc pipe for the body of the instrument.. i would like to use metal pads, like screws that i could simply touch, and my finger touching them would be detected and sounded, if not, a button would work as well...

so, what could i use to detect the location of my fingers?.. are there any kind of touch sensor i can use for this purpose that would be small enough?...

and lastly, i would like to be able to be able to feed the information into a programmable midi controller, or atleast into my computer where i can run a suitable program and program the fingering positions of different instruments to the bottons/sensors...

any idea how to go about this?

hmm.. found a device by hale microsystems called the UMC-32... seems to do what im looking for, but what would i use for touch sensors, and how would i detect the amount of air blown into it should i decide to add that feature?

Take a look at differential pressure sensors for touch sensing. I don't know if they would be sensitive enough to transduce the vibrating pressure waves from a mouthpiece or reed.

hmm.. im reading about a device called an e chanter, that people use to practice bagpipes and it would appear they have metal screws wired directly to pins on an arduino microcontroller.. are microcontrollers able to detect any kind of a single from touching a screw as opposed to using a button?

e chanter?

Hi jason41987:

I would like to read more about the e chanter....
Currently I am re-doing some of my Stamp Parallax projects. One of those was a Electronic Wind/Brass controller (to MIDI) ....+5 years ago the results were fair. There was a lot of areas for improvements. I used buttons to get the key values and an electrec + OpAmp + ADC to detect changes in volume.

At the moment I am working on a Drum pad percussion MIDI Controller on this one I was not so succesful so I re-start this one first.

You can check the circuits that I used here in these wonderful forums. My area of knowledge is not electronics so I am always grateful of all the help I received from the Electro Tech team.

Check under PRPROG posting. I am sure those circuits can be improved and apply for your Arduino projects.

PRPROG

so you use a basic stamp, with a pic clone processor as your midi controller?... im not sure if i should get into the pic or avr world, or even ARM for more powerful devices, but im thinking a woodwind midi controller using the AVR or pic processor would be a good way to go, how do you get all the inputs into the stamp? there doesnt seem to be enough digital or analog inputs for a midi controller, so im wondering what you do?...

im guessing besides the stamp you also need a midi chip as well, or are you just sending the button information through a USB port so you can write instrument profiles on your computer?...

one thing i would like to do is maybe save different button combinations to different MIDI notes and have a button i can press to select different "modes" each mode being a different instrument, flute, saxophone, clarinet, bagpipes, trumpet, etc.... but it would also be cool if i could take a recording of the individual notes of the instrument and have those play back instead of a MIDI sound

the echanter uses an arduino and it looks as if the metal screws are connected directly to the digital inputs on the chip itself, so i dont know how this is supposed to detect the presence of a finger.. any ideas?

heres the idea im having right now... im thinking of making a mouthpiece thatll contain the circuitry and the pressure sensor in the mouth piece to detect how hard youre blowing into it.. this will be wired in as an analog control... then i want to make seperate instrument bodies with the spacing, and hole configurations of the different instruments, these parts will contain the digital sensors, as well as a linear potentiometer (analog)... and i want to have some kind of round multi-pin connector to connect the body of the instrument to the electronics of the instrument....

for the electronics portion im thinking of using an arduino or similar pic-based project board (havent decided which one) but i would like to have a microSD card slot on it, on the microSD card to store the profiles (key configurations and sounds) of different instruments... so when a key is played i would like the appropriate synthesized sound of that instrument to play, with some means of pitch-shifting that sound for playing vibrato in the same manner as you would apply vibrato to the instrument being replicated

if at all possible it would be nice to have some way for the circuitry in the mouth piece to detect which instrument body is inserted into it possibly by using a resistor to change the voltage being returned to the chip on one of the pins, have the different unique voltage signatures programmed into the chip so that the brains of the instrument can automatically start playing in that pre-programmed mode...

so what i will need is a small project board, im thinking arduino, but a pickit could work too... depending on the instrument, metal screw sensors for holes, and buttons to replicate the keys of keyed woodwind and brass instruments, a piezo-electric for the mouth piece, and atleast one analog control for the individual instruments depending on how that instrument applies vibrato..

the circuitry itself will need to be able to handle, my guess is no less than 10 digital inputs, probably not much more than 3.. so if i could have 16 analog/digital inputs on the device i think this would work, and some way of detecting the voltage coming back from the device to automatically select a pre-programmed profile of the instrument body plugged in...

my question is, is this doable, if so, what kind of hardware am i looking at for the circuitry of this?... will i need any chips to synthesize the MIDI signal into the proper tone and character of the instrument or can the processor itself do this?.. i could use add-on boards for the micro SD expansion unless the arduino used already had the feature, LCD display wont be neccessary, and this device will need to be able to amplify the audio signal to play back directly to headphones... for power supply i would like to put a few battery pack cells together and make a rechargable battery pack with a simple recharger capable of running off the voltage of a USB slot

if possible, i would like to also be able to play the unprocessed MIDI information back into the computer via USB in a way it can interact with built in midi/HID drivers

so.. if anyone would like to help me with this project more in depth, send me an IM and we can discuss it further.. or post questions, ideas, or advice here

eWoodwind instrument

jason41987:

Those are a lot of possibilities/ideas ...I would suggest that you start by building a prototype with just the simple requirement and then extent the design accordingly. Since I decided to used the BS2 Parallax stamp I do have a limit of 16 in/out pins and no analog input.

The Stamp electronic woodwind instrument i built is just a controller. It generate the MIDI out signal that can be connected to any regular MIDI device, including any PC with a suitable MIDI interface and sounds. I manage to used a multiplexer chip to expand the number of virtual in/outs of the Parallax stamp. For analog convertion I used a ADC0831 chip (very easy to interface to the Stamp.

prprog

hmm... seems simple enough... i was thinking of building the first model with an avr328 8-bit chip, 28-pins, didnt know you could use a multiplexer chip to add inputs and outputs... learned you can wire the metal touch sensors directly to the chip, but i dont play any of the instruments i want to mimic yet so first i need to understand how they function to accurately duplicate it

i heard 8 bits was a little low for all the onboard midi processing as well as direct input of the touch sensors, so i was thinking of wiring the touch sensor aspects of the instrument to a capacitive touch sensor chip and output the midi directly to a computer via USB if possible....

i wonder though, would a 32 bit, 40 pin chip be able to handle all inputs, uncluding the touch sensors while still being able to process the midi signals into the sounds of the instrument on board without the extra chips? or am i better off using an 8-bit chip and additional chips to provide the other functions?