3 part harmony?

[mark lafond]

Hello,

New to synth, new to mozzi, new to arduino.  Yeah, noobie!

I'm a model railroader interested in creating diesel train horn sound, harmonizing 3 notes: 493.88, 622.25, and 880.00 Hz, with my arduino triggered with a momentary push button. 

While I'm at it, I could use a bell that repeats as long as the button is held down.

Last, I'm hoping I'lll still be able to use the arduino for other layout functions (i.e. crossing gates)

I could use any help. Thanks!

[Mr Sensorium]

Hi Mark,
once you have the library installed, there are some examples you can base your sketch on.  Here is Examples>Mozzi>01.Basics>Sinewave modified to play 3 tones at the frequencies you listed.  You could use an envelope to shape the amplitude of the sound(s), like in Examples>Mozzi>07.Envelopes>ADSR_Audio_Rate_Envelope, or ADSR_Audio_Rate_Envelope_x2, which shows how to envelope  and sum two sources.  An example showing how to use a button to change audio is attached.

#include <MozziGuts.h>
#include <Oscil.h> // oscillator template
#include <tables/sin2048_int8.h> // sine table for oscillator

// use: Oscil <table_size, update_rate> oscilName (wavetable), look in .h file of table #included above
Oscil <SIN2048_NUM_CELLS, AUDIO_RATE> aSin1(SIN2048_DATA);
Oscil <SIN2048_NUM_CELLS, AUDIO_RATE> aSin2(SIN2048_DATA);
Oscil <SIN2048_NUM_CELLS, AUDIO_RATE> aSin3(SIN2048_DATA);

void setup(){
  startMozzi(CONTROL_RATE); // set a control rate of 64 (powers of 2 please)
  aSin1.setFreq(493.88f); // set the frequency
  aSin2.setFreq(622.25f);
  aSin3.setFreq(880.00f);
}


void updateControl(){
  // put changing controls in here
}


int updateAudio(){
  return  ((int)aSin1.next() + aSin2.next() + aSin3.next())>>1;
}


void loop(){
  audioHook(); // required here
}

The example 08.Samples>Sample plays a sample repeatedly using a timer, or you can play a sample looping without needing to retrigger it with a timer by using setLoopingOn().  The docs for Sample are here: https://sensorium.github.io/Mozzi/doc/html/class_sample.html#a40e76011d841b84d2d54bf2cec6c4d5f

You could probably fit some more things into a sketch, though space for samples is a consideration..
Also, if you are new to Arduino and Mozzi, the Arduino examples are useful tutorials, and there is this tute for Mozzi...https://sensorium.github.io/Mozzi/learn/

Good luck
Tim

[mark lafond]

Thanks, Mr. Senorium!  You've given me a bunch to check out.  I'll get back to you.

[mark lafond]

Well I've certainly learned a lot, but I need your help!  The following does sound 3 notes simultaneously for the duration of a button push.  I can't get the ASDR envelope to work, even though it works in a separate program that sounds one note repeatedly, without button control, in other words, the lines of code that should affect the notes have no effect:

#include <MozziGuts.h>

#include <Oscil.h> // oscillator template

#include <tables/chum78_int8.h> // sine table for oscillator

#include <EventDelay.h>

#include <ADSR.h>

// use: Oscil <table_size, update_rate> oscilName (wavetable), look in .h file of table #included above

Oscil <CHUM78_NUM_CELLS, AUDIO_RATE> aSin1(CHUM78_DATA);

Oscil <CHUM78_NUM_CELLS, AUDIO_RATE> aSin2(CHUM78_DATA);

Oscil <CHUM78_NUM_CELLS, AUDIO_RATE> aSin3(CHUM78_DATA);

Oscil <8192, AUDIO_RATE> aOscil(CHUM78_DATA);;

// set pin numbers:

const int buttonPin = 4;     // the number of the pushbutton pin

int buttonState = 0;         // variable for reading the pushbutton status\

// use #define for CONTROL_RATE, not a constant

#define CONTROL_RATE 64 // powers of 2 please

// for triggering the envelope

EventDelay noteDelay;

ADSR <CONTROL_RATE, CONTROL_RATE> envelope;

byte gain;

void setup(){

  startMozzi(CONTROL_RATE); // set a control rate of 64 (powers of 2 please)

}

unsigned int duration, attack, decay, sustain, release_ms;

void updateControl(){

  // put changing controls in here

    // read the state of the pushbutton value:

  buttonState = digitalRead(buttonPin);

if(noteDelay.ready()){

      // choose envelope levels. Necessary but overwritten below

      byte attack_level = 1000;

      byte decay_level = 1000;

      envelope.setADLevels(attack_level,decay_level);  

    {  

 // Set the ASDR Levels

       attack = 250;

       decay = 500;

       sustain = 1000;

       release_ms = 500;

     }

     envelope.setTimes(attack,decay,sustain,release_ms);    

     envelope.noteOn();

     noteDelay.start(attack+decay+sustain+release_ms);

   } 

   

  envelope.update();

  gain = envelope.next(); // this is where it's different to an audio rate envelope     

  aOscil.setFreq(500);

  

{ if (buttonState == HIGH) {     

  aSin1.setFreq(600); // set the frequency

  aSin2.setFreq(880);

  aSin3.setFreq(1200); 

}

else {

  aSin1.setFreq(0); // set the frequency

//  aSin2.setFreq(0);

//  aSin3.setFreq(0);

}

}

}

int updateAudio(){

 return  ((int)aSin1.next() + aSin2.next() + aSin3.next())>>1;

 return (int) (gain * aOscil.next())>>8;

}

void loop(){

  audioHook(); // required here

}

[Mr Sensorium]

Hi Mark,
this works for me (I changed the waveform to square - not sure the most appropriate for modelling a train whistle ... or would it be an electronic signal anyway?):

#include <MozziGuts.h>
#include <Oscil.h> // oscillator template

#include <tables/smoothsquare8192_int8.h> // squarewave table for oscillator
#include <ADSR.h>

const int buttonPin = 4;     // the number of the pushbutton pin

Oscil <SMOOTHSQUARE8192_NUM_CELLS, AUDIO_RATE> aSig1(SMOOTHSQUARE8192_DATA);
Oscil <SMOOTHSQUARE8192_NUM_CELLS, AUDIO_RATE> aSig2(SMOOTHSQUARE8192_DATA);
Oscil <SMOOTHSQUARE8192_NUM_CELLS, AUDIO_RATE> aSig3(SMOOTHSQUARE8192_DATA);

ADSR <CONTROL_RATE, AUDIO_RATE> envelope;


void setup() {
  startMozzi();
  envelope.setADLevels(255,255);
  envelope.setTimes(250,500,1000,500); // will release after 1750 ms or earlier if button is released sooner
  aSig1.setFreq(600); // set the frequency
  aSig2.setFreq(880);
  aSig3.setFreq(1200);
}

boolean triggered = false;

void updateControl() {
  if (digitalRead(buttonPin) == HIGH) {
    if (!triggered){ // only happens once at start of each button press
      envelope.noteOn();
      triggered = true;
    }
  }
  else { // button off
    envelope.noteOff();
    triggered = false;
  }
  envelope.update();
}


int updateAudio(){
  int whistle = ((int)aSig1.next() + aSig2.next() + aSig3.next())>>1;
  return ((long)envelope.next() * whistle)>>8;

[mark lafond]

AWESOME!!  THANKS!!

On Monday, April 13, 2015 at 9:14:42 PM UTC-4, mark lafond wrote: