// 2 voices on 1 Arduino

// demo by John Harrison

// Nov 28, 2011

// public domain


// v 1.0


// for the demo to work unmodified, hook up a 1Kish resistor to pin 11 and a 1Kish resistor to pin 12.

// tie the other ends of the resistors together and hook those up to an amp and speaker.

// or you could skip the resistors and hook up pin 11 to one side of a stereo amp and pin 12 to the other side


// You have to included pitches.h. Below shows the path on my computer. Yours will be similar
#include "C:\Documents and Settings\John\Desktop\arduino-0021\examples\2.Digital\toneKeyboard\pitches.h"


// as stated above,
// connect amp/speaker to FIRST_TONE_PIN and subsequent.

// for example, if FIRST_TONE_PIN is 11 and NUM_OF_VOICE is 2,

// connect amp/speaker to arduino  pin 11 and pin 12.

// if using the same amp/speaker for both pins, have each

// pin go through a 1Kish resistor before being summed together


#define FIRST_TONE_PIN 11

#define NUM_OF_VOICES 2



// a future version will support more than 2 simultaneous voices


// notes in the melody:

int melody1[] = {
  NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_B4, NOTE_D5, NOTE_C5, NOTE_A4, 0, NOTE_C5, NOTE_E5, NOTE_A5, NOTE_B5, 0, NOTE_E5, NOTE_GS5, NOTE_B5, NOTE_C6, 0, NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_B4, NOTE_D5, NOTE_C5, NOTE_A4, 0, NOTE_C5, NOTE_E5, NOTE_A5, NOTE_B5, 0, NOTE_E5, NOTE_C6, NOTE_B5, NOTE_A5};



// melody note lengths in milliseconds

int mel1Durations[] = {
  200, 200, 200, 200, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400, 200, 200, 200, 200, 200, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400 };



// notes in the harmony:

int harmony1[] = {
  NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_B4, NOTE_D5, NOTE_C5, NOTE_A4, 0, NOTE_C5, NOTE_E5, NOTE_A5, NOTE_B5, 0, NOTE_E5, NOTE_GS5, NOTE_B5, NOTE_C6, 0, NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_B4, NOTE_D5, NOTE_C5, NOTE_A4, 0, NOTE_C5, NOTE_E5, NOTE_A5, NOTE_B5, 0, NOTE_E5, NOTE_C6, NOTE_B5, NOTE_A5};



// harmony note lengths in milliseconds

int harm1Durations[] = {
  200, 200, 200, 200, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400, 200, 200, 200, 200, 200, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400, 200, 200, 200, 200, 400 };



void setup() {
  
	Serial.begin(9600);
  
	for (unsigned char i = 0; i < NUM_OF_VOICES; i++) {
    
		pinMode(i+FIRST_TONE_PIN,OUTPUT);
  
	}
  
  
	// in this test example, the harmony and the melody are initially the same
  
	// so we raise the harmony up an octave and slow it down to 1/2 speed
  
	for (int j = 0; j < (sizeof(harmony1) / sizeof(int)); j++) {
    
		harmony1[j] = harmony1[j] << 1;
    
		harm1Durations[j] = harm1Durations[j] << 1;
  
	}
  
  

	// call magic function to play both voices
  
	playTune(melody1, sizeof(melody1)/sizeof(int), mel1Durations, harmony1, sizeof(harmony1)/sizeof(int), 		harm1Durations);

}



void loop() {
  
	// if we get here, we played the melody
  
	// all we can do is pee in corner of circular room
  
	while (1)
    ;

}


// no need to modify anything below for basic use

void playTune(int melody[], int melLength, int melDurations[], int harmony[], int harmLength, int harmDurations[])
{
  	unsigned int Counts[] = { 0, 0};
  
	unsigned int Periods[] = { 0, 0};
  
	unsigned char States[] = { 0, 0};
  
  
	unsigned long stopTimeNote1 = 0;
  
	unsigned long stopTimeNote2 = 0;
  
	unsigned char TimedPin = 0;
  
	unsigned int CurrentCount = 0;
  
	unsigned char i;
  
	unsigned char indexMel = 0, indexHarm = 0;
  
  
	while (1) {
    
		CurrentCount = Counts[0];
    
		TimedPin = 0;
    
		for (i=1;i<NUM_OF_VOICES;i++) {
      
			if (Counts[i] < CurrentCount) {
        
				TimedPin = i;
        
				CurrentCount = Counts[i];
      
			} 
		// for
    
		}	
    
		if (CurrentCount > 3)
      
			delayMicroseconds(CurrentCount);
    
		if (Periods[TimedPin] < 65535)
      
			States[TimedPin] = !States[TimedPin];
    
		digitalWrite(FIRST_TONE_PIN+TimedPin,States[TimedPin]);

    
		if (millis() >= stopTimeNote1) {
      
			if (indexMel >= melLength)
        
				break;
      
			stopTimeNote1 = millis() + melDurations[indexMel];
      
			Periods[0] = 1000000 / melody[indexMel++];
    
		}
    
		if (millis() >= stopTimeNote2) {
      
			if (indexHarm >= harmLength)
        
				break;
      
			stopTimeNote2 = millis() + harmDurations[indexHarm];
      
			Periods[1] = 1000000 / harmony[indexHarm++];
    
		}
    
    
		for (i = 0; i < NUM_OF_VOICES; i++) {
    
  
			Counts[i] = Counts[i] - CurrentCount;
    
		}
    
		Counts[TimedPin] = Periods[TimedPin];
  
	}

}