#include <avr/pgmspace.h>
#include<avr/interrupt.h>

//Einstellen von Miditonhöhen mit den Timern 1 und 3 im CTC-Mode.

//const unsigned int LOOKUP_OCR1[] = PROGMEM {
const unsigned int LOOKUP_OCR1[] = {
61155, 57723, 54483, 51425, 48539, 45814, 43243, 40816, 38525, 36363, 
34322, 32395, 30577, 28861, 27241, 25712, 24269, 22907, 21621, 20407, 
19262, 18181, 17160, 16197, 15288, 14430, 13620, 12855, 12134, 11453, 
10810, 10203, 9630, 9090, 8580, 64792, 61155, 57723, 54483, 51425, 
48539, 45814, 43243, 40816, 38525, 36363, 34322, 32395, 30577, 28861, 
27241, 25712, 24269, 22907, 21621, 20407, 19262, 18181, 17160, 16197, 
15288, 14430, 13620, 12855, 12134, 11453, 10810, 10203, 9630, 9090, 
8580, 8098, 7644, 7214, 6809, 6427, 6066, 5726, 5404, 5101, 
4815, 4544, 4289, 4049, 3821, 3607, 3404, 3213, 3033, 2862, 
2702, 2550, 2407, 2272, 2144, 2024, 1910, 1803, 1702, 1606, 
1516, 1431, 1350, 1275, 1203, 1135, 1072, 1011, 955, 901, 
850, 803, 757, 715, 675, 637, 601, 567, 535, 505, 
477, 450, 425, 401, 378, 357, 337, 318};


//const unsigned int LOOKUP_N1[] = PROGMEM {
const unsigned int LOOKUP_N1[] = {
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1};


//const unsigned int LOOKUP_OCR0[] = PROGMEM {
const unsigned int LOOKUP_OCR0[] = {
477, 450, 425, 401, 378, 357, 337, 318, 300, 283, 
267, 1011, 955, 901, 850, 803, 757, 715, 675, 637, 
601, 567, 535, 505, 477, 450, 425, 401, 378, 357, 
337, 318, 300, 283, 267, 1011, 955, 901, 850, 803, 
757, 715, 675, 637, 601, 567, 535, 505, 477, 450, 
425, 401, 378, 357, 337, 318, 300, 283, 267, 252, 
238, 224, 212, 200, 189, 178, 168, 158, 149, 141, 
133, 1011, 955, 901, 850, 803, 757, 715, 675, 637, 
601, 567, 535, 505, 477, 450, 425, 401, 378, 357, 
337, 318, 300, 283, 267, 252, 238, 224, 212, 200, 
189, 178, 168, 158, 149, 141, 133, 1011, 955, 901, 
850, 803, 757, 715, 675, 637, 601, 567, 535, 505, 
477, 450, 425, 401, 378, 357, 337, 318};

//const unsigned int LOOKUP_N0[] = PROGMEM {
const unsigned int LOOKUP_N0[] = {
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 
5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 
4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1};


//const unsigned int LOOKUP_FEHLER0 = PROGMEM {
const unsigned int LOOKUP_FEHLER0[] = {
8, 1, 14, 10, 10, 3, 8, 6, 1, 6, 
9, 7, 8, 1, 6, 10, 10, 3, 8, 6, 
1, 6, 9, 7, 8, 1, 14, 10, 10, 3, 
8, 6, 1, 6, 9, 7, 8, 1, 6, 10, 
10, 3, 8, 6, 1, 6, 9, 7, 8, 1, 
14, 10, 10, 3, 8, 6, 1, 6, 9, 7, 
8, 37, 14, 10, 36, 3, 8, 48, 57, 6, 
9, 7, 8, 1, 6, 10, 10, 3, 8, 6, 
1, 6, 9, 7, 8, 1, 14, 10, 10, 3, 
8, 6, 1, 6, 9, 7, 8, 37, 14, 10, 
36, 3, 8, 48, 57, 6, 9, 7, 8, 1, 
6, 10, 10, 3, 8, 6, 1, 6, 9, 7, 
8, 1, 14, 10, 10, 3, 8, 6};

int ZEIT=0;
bool ZUSTAND=false;

int TON=0;

ISR(TIMER4_COMPA_vect)
{
    if(ZEIT==4000) 
    {
      digitalWrite(0,ZUSTAND);
      ZUSTAND=!ZUSTAND;        
      ZEIT=0;
      
      TON++;
      TON%=25;
      
      setzeMidihoehe0(TON+48);  //Timer 3
      setzeMidihoehe1(TON+48+4);  //Timer 3
      setzeMidihoehe3(TON+48+7);  //Timer 3
      
    }  
    ZEIT++;
}

void initTimer4()
{
  //Vorteilung 2
  TCCR4B &= ~(1<<CS43);
  TCCR4B &= ~(1<<CS42);
  TCCR4B &= ~(1<<CS41);    
  TCCR4B |=  (1<<CS40);
 
  TIMSK4 |= (1<<OCIE4A); //Mode 4
  sei(); 
 
  //Andere Frequenzberechnung:   
  //f = fclk/(2*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 500000/440 - 1 ==  
  //OCR4B=268; 
  OCR4A=400; 
//  OCR4C=10; 
    
//OCR4B=268;     
//    OCR4A=2; 
//durch Interrupt gesteuert:
  pinMode(0,OUTPUT);    
}

void initTimer0()
{
  TCCR0B=0;
  TCCR0A=0;
  
  TCCR0B &= ~(1<<WGM02);
  TCCR0A |=  (1<<WGM01);
  TCCR0A &= ~(1<<WGM00);
    
  //Vorteilung 64
  TCCR0B &= ~(1<<CS02);
  TCCR0B |= (1<<CS01);
  TCCR0B |= (1<<CS00);
    
  //f = fclk/(2*N*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 125000/880 - 1 ==  141
  //KORRIGIERT:
  //********************************
  //OCR0A = 62500/440 - 1 ==  142
  //OCR0A = 16000000/(f*4*N) - 1 ==  142
  //********************************
  
  OCR0A=141;  
  
  //Toggle auf OC1A:
  TCCR0A &= ~(1<<COM0A1);
  TCCR0A |=  (1<<COM0A0);
  pinMode(11,OUTPUT);          //OC0A
}

void initTimer1()
{
  TCCR1B &= ~(1<<WGM13); //Mode 4
  TCCR1B |= (1<<WGM12);
  TCCR1A &= ~(1<<WGM11);
  TCCR1A &= ~(1<<WGM10);
    
  //Vorteilung 1: 16000000Hz
  TCCR1B &= ~(1<<CS12);
  TCCR1B &= ~(1<<CS11);
  TCCR1B |= (1<<CS10);
    
  //f = fclk/(2*N*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 8000000/440 - 1 ==  18181
  //KORRIGIERT:
  //********************************
  //OCR1A = 4000000/440 - 1 ==  9091
  //OCR1A = 16000000/(f*4*N) - 1 ==  9091
  //********************************
  OCR1A=9091;  //0,5Hz == 4 Schläge!
  
  //Toggle auf OC1A:
  TCCR1A &= ~(1<<COM1A1);
  TCCR1A |=  (1<<COM1A0);
  pinMode(9,OUTPUT);      
}

void initTimer3()
{
//  TCCR1B |= (1<<WGM13); //Mode 12
  TCCR3B &= ~(1<<WGM33); //Mode 4
  TCCR3B |= (1<<WGM32);
  TCCR3A &= ~(1<<WGM31);
  TCCR3A &= ~(1<<WGM30);
    
  //Vorteilung 1: 16000000Hz
  TCCR3B &= ~(1<<CS32);
  TCCR3B &= ~(1<<CS31);
  TCCR3B |= (1<<CS30);
    
  //f = fclk/(2*N*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 8000000/440 - 1 ==  18181
  OCR3A=18181/2;  //0,5Hz == 4 Schläge!
  
  //Toggle auf OC1A:
  TCCR3A &= ~(1<<COM3A1);
  TCCR3A |=  (1<<COM3A0);
  pinMode(5,OUTPUT);    //OC3A  
}




void setzeMidihoehe0(int midi)  //Timer 0
{
  TCCR0B &= 248; //unteren drei Bit löschen
  TCCR0B |= LOOKUP_N0[midi];
  OCR0A=LOOKUP_OCR0[midi];
}
void setzeMidihoehe1(int midi)  //Timer 1
{
  TCCR1B &= 248; //unteren drei Bit löschen
  TCCR1B |= LOOKUP_N1[midi];
  OCR1A=LOOKUP_OCR1[midi];
}
void setzeMidihoehe3(int midi)  //Timer 3
{
  TCCR3B &= 248; //unteren drei Bit löschen
  TCCR3B |= LOOKUP_N1[midi];
  OCR3A=LOOKUP_OCR1[midi];
}


void setup() 
{
    initTimer0();
    initTimer1();
    initTimer3();
    initTimer4();
}

void loop()
{
}

Code 0-1: Chromatische Aufwärtsbewegung eines Dreiklangs

#include <avr/pgmspace.h>
#include<avr/interrupt.h>

//Zuordnung Analog zu Digital
//A0 = D18
//A1 = D19
//A2 = D20
//A3 = D21
//A4 = D22
//A5 = D23
//A6 = D24
//A7 = D25
//A8 = D26
//A9 = D27
//A10 = D28
//A11 = D29

//Zuordnungen:
//Timer0: 11  A3 D21
//Timer1:  9  A4 D22
//Timer2:  5  A5 D23


//Einstellen von Miditonhöhen mit den Timern 1 und 3 im CTC-Mode.

//const unsigned int LOOKUP_OCR1[] = PROGMEM {
const unsigned int LOOKUP_OCR1[] = {
61155, 57723, 54483, 51425, 48539, 45814, 43243, 40816, 38525, 36363, 
34322, 32395, 30577, 28861, 27241, 25712, 24269, 22907, 21621, 20407, 
19262, 18181, 17160, 16197, 15288, 14430, 13620, 12855, 12134, 11453, 
10810, 10203, 9630, 9090, 8580, 64792, 61155, 57723, 54483, 51425, 
48539, 45814, 43243, 40816, 38525, 36363, 34322, 32395, 30577, 28861, 
27241, 25712, 24269, 22907, 21621, 20407, 19262, 18181, 17160, 16197, 
15288, 14430, 13620, 12855, 12134, 11453, 10810, 10203, 9630, 9090, 
8580, 8098, 7644, 7214, 6809, 6427, 6066, 5726, 5404, 5101, 
4815, 4544, 4289, 4049, 3821, 3607, 3404, 3213, 3033, 2862, 
2702, 2550, 2407, 2272, 2144, 2024, 1910, 1803, 1702, 1606, 
1516, 1431, 1350, 1275, 1203, 1135, 1072, 1011, 955, 901, 
850, 803, 757, 715, 675, 637, 601, 567, 535, 505, 
477, 450, 425, 401, 378, 357, 337, 318};


//const unsigned int LOOKUP_N1[] = PROGMEM {
const unsigned int LOOKUP_N1[] = {
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1};


//const unsigned int LOOKUP_OCR0[] = PROGMEM {
const unsigned int LOOKUP_OCR0[] = {
477, 450, 425, 401, 378, 357, 337, 318, 300, 283, 
267, 1011, 955, 901, 850, 803, 757, 715, 675, 637, 
601, 567, 535, 505, 477, 450, 425, 401, 378, 357, 
337, 318, 300, 283, 267, 1011, 955, 901, 850, 803, 
757, 715, 675, 637, 601, 567, 535, 505, 477, 450, 
425, 401, 378, 357, 337, 318, 300, 283, 267, 252, 
238, 224, 212, 200, 189, 178, 168, 158, 149, 141, 
133, 1011, 955, 901, 850, 803, 757, 715, 675, 637, 
601, 567, 535, 505, 477, 450, 425, 401, 378, 357, 
337, 318, 300, 283, 267, 252, 238, 224, 212, 200, 
189, 178, 168, 158, 149, 141, 133, 1011, 955, 901, 
850, 803, 757, 715, 675, 637, 601, 567, 535, 505, 
477, 450, 425, 401, 378, 357, 337, 318};

//const unsigned int LOOKUP_N0[] = PROGMEM {
const unsigned int LOOKUP_N0[] = {
5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 
5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 
4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
1, 1, 1, 1, 1, 1, 1, 1};


//const unsigned int LOOKUP_FEHLER0 = PROGMEM {
const unsigned int LOOKUP_FEHLER0[] = {
8, 1, 14, 10, 10, 3, 8, 6, 1, 6, 
9, 7, 8, 1, 6, 10, 10, 3, 8, 6, 
1, 6, 9, 7, 8, 1, 14, 10, 10, 3, 
8, 6, 1, 6, 9, 7, 8, 1, 6, 10, 
10, 3, 8, 6, 1, 6, 9, 7, 8, 1, 
14, 10, 10, 3, 8, 6, 1, 6, 9, 7, 
8, 37, 14, 10, 36, 3, 8, 48, 57, 6, 
9, 7, 8, 1, 6, 10, 10, 3, 8, 6, 
1, 6, 9, 7, 8, 1, 14, 10, 10, 3, 
8, 6, 1, 6, 9, 7, 8, 37, 14, 10, 
36, 3, 8, 48, 57, 6, 9, 7, 8, 1, 
6, 10, 10, 3, 8, 6, 1, 6, 9, 7, 
8, 1, 14, 10, 10, 3, 8, 6};

int restdauer[] = {0,0,0};

int ZEIT=0;
bool ZUSTAND=false;

unsigned long int TON=0;

ISR(TIMER4_COMPA_vect)
{
    if(ZEIT==4000) 
//    if(ZEIT==32000) 
    {
      digitalWrite(0,ZUSTAND);
      ZUSTAND=!ZUSTAND;        
      ZEIT=0;
      
      TON++;
      TON%=49;
      
      setzeMidihoehe0(TON+36);  //Timer 3
      setzeMidihoehe1(TON+36+4);  //Timer 3
      setzeMidihoehe3(TON+36+7);  //Timer 3
      
    }  
    ZEIT++;

    if(restdauer[0]==0) 
    {
        pinMode(21,0);
        digitalWrite(21,0);
    }
    if(restdauer[1]==0) 
    {
        pinMode(22,0);
        digitalWrite(22,0);
    }
    if(restdauer[2]==0) 
    {
        pinMode(23,0);
        digitalWrite(23,0);
    }
    
    if(restdauer[0]>=0) restdauer[0]--;
    if(restdauer[1]>=0) restdauer[1]--;
    if(restdauer[2]>=0) restdauer[2]--;
}

void initTimer4()
{
  //Vorteilung 2
  TCCR4B &= ~(1<<CS43);
  TCCR4B &= ~(1<<CS42);
  TCCR4B &= ~(1<<CS41);    
  TCCR4B |=  (1<<CS40);
 
  TIMSK4 |= (1<<OCIE4A); //Mode 4
  sei(); 
 
  //Andere Frequenzberechnung:   
  //f = fclk/(2*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 500000/440 - 1 ==  
  //OCR4B=268; 
  OCR4A=400; 
//  OCR4C=10; 
    
//OCR4B=268;     
//    OCR4A=2; 
//durch Interrupt gesteuert:
  pinMode(0,OUTPUT);    
}

void initTimer0()
{
  TCCR0B=0;
  TCCR0A=0;
  
  TCCR0B &= ~(1<<WGM02);
  TCCR0A |=  (1<<WGM01);
  TCCR0A &= ~(1<<WGM00);
    
  //Vorteilung 64
  TCCR0B &= ~(1<<CS02);
  TCCR0B |= (1<<CS01);
  TCCR0B |= (1<<CS00);
    
  //f = fclk/(2*N*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 125000/880 - 1 ==  141
  //KORRIGIERT:
  //********************************
  //OCR0A = 62500/440 - 1 ==  142
  //OCR0A = 16000000/(f*4*N) - 1 ==  142
  //********************************
  
  OCR0A=141;  
  
  //Toggle auf OC1A:
  TCCR0A &= ~(1<<COM0A1);
  TCCR0A |=  (1<<COM0A0);
  pinMode(11,OUTPUT);          //OC0A
  pinMode(21,OUTPUT);          //A3 als Schalter
  digitalWrite(21,0);
}

void initTimer1()
{
  TCCR1B &= ~(1<<WGM13); //Mode 4
  TCCR1B |= (1<<WGM12);
  TCCR1A &= ~(1<<WGM11);
  TCCR1A &= ~(1<<WGM10);
    
  //Vorteilung 1: 16000000Hz
  TCCR1B &= ~(1<<CS12);
  TCCR1B &= ~(1<<CS11);
  TCCR1B |= (1<<CS10);
    
  //f = fclk/(2*N*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 8000000/440 - 1 ==  18181
  //KORRIGIERT:
  //********************************
  //OCR1A = 4000000/440 - 1 ==  9091
  //OCR1A = 16000000/(f*4*N) - 1 ==  9091
  //********************************
  OCR1A=9091;  //0,5Hz == 4 Schläge!
  
  //Toggle auf OC1A:
  TCCR1A &= ~(1<<COM1A1);
  TCCR1A |=  (1<<COM1A0);
  pinMode(9,OUTPUT);      
  pinMode(22,OUTPUT);          //A4 als Schalter
  digitalWrite(22,0);
}

void initTimer3()
{
//  TCCR1B |= (1<<WGM13); //Mode 12
  TCCR3B &= ~(1<<WGM33); //Mode 4
  TCCR3B |= (1<<WGM32);
  TCCR3A &= ~(1<<WGM31);
  TCCR3A &= ~(1<<WGM30);
    
  //Vorteilung 1: 16000000Hz
  TCCR3B &= ~(1<<CS32);
  TCCR3B &= ~(1<<CS31);
  TCCR3B |= (1<<CS30);
    
  //f = fclk/(2*N*(OCR1A+1))
  //OCR1A = (fclk/(f*2*N))-1
  //OCR1A = 8000000/440 - 1 ==  18181
  OCR3A=18181/2;  //0,5Hz == 4 Schläge!
  
  //Toggle auf OC1A:
  TCCR3A &= ~(1<<COM3A1);
  TCCR3A |=  (1<<COM3A0);
  pinMode(5,OUTPUT);    //OC3A  
  pinMode(23,OUTPUT);          //A5 als Schalter
  digitalWrite(23,0);
}




void setzeMidihoehe0(int midi)  //Timer 0
{
  TCCR0B &= 248; //unteren drei Bit löschen
  TCCR0B |= LOOKUP_N0[midi];
  OCR0A=LOOKUP_OCR0[midi];
  
  restdauer[0]=100;
  pinMode(21,OUTPUT);  
  digitalWrite(21,1);
}
void setzeMidihoehe1(int midi)  //Timer 1
{
  TCCR1B &= 248; //unteren drei Bit löschen
  TCCR1B |= LOOKUP_N1[midi];
  OCR1A=LOOKUP_OCR1[midi];
  restdauer[1]=100;
  pinMode(22,OUTPUT);  
  digitalWrite(22,1);
  
}
void setzeMidihoehe3(int midi)  //Timer 3
{
  TCCR3B &= 248; //unteren drei Bit löschen
  TCCR3B |= LOOKUP_N1[midi];
  OCR3A=LOOKUP_OCR1[midi];
  restdauer[2]=100;
  pinMode(23,OUTPUT);  
  digitalWrite(23,1);
}


void setup() 
{
    initTimer0();
    initTimer1();
    initTimer3();
    initTimer4();
}

void loop()
{
}

Code 0-2: Auslösen der Töne über digitale Ausgänge bei A3, A4, A5