#include <16F628.h>
#use delay(clock=4000000)
#fuses XT,PUT,BROWNOUT,MCLR,NOWDT,NOPROTECT,NOLVP


#define TONE_PIN  PIN_A0
#define nSIZE 25
long ErrCor;

//            NOTE                 FREQUENCY
//                     Octave0  Octave1  Octave2  Octave3
const long C_NOTE[4]  ={ 262,     523,     1047,     2093};
const long Cf_NOTE[4]  ={ 277,     554,     1109,     2217};
const long D_NOTE[4]  ={ 294,     587,     1175,     2349};
const long Df_NOTE[4]  ={ 311,     622,     1245,     2489};
const long E_NOTE[4]  ={ 330,     659,     1329,     2637};
const long F_NOTE[4]  ={ 349,     698,     1397,     2794};
const long Ff_NOTE[4]  ={ 370,     740,     1480,     2960};
const long G_NOTE[4]  ={ 392,     784,     1568,     3136};
const long Gf_NOTE[4]  ={ 415,     831,     1661,     3322};
const long A_NOTE[4]  ={ 440,     880,     1760,     3520};
const long Af_NOTE[4]  ={ 466,     923,     1865,     3729};
const long B_NOTE[4]  ={ 494,     988,     1976,     3951};


void generate_tone(long frequency, long duration);
void do_delay(int ms_delay, int num_ms, int us_delay, int num_us);  

const struct note2
{
   long tone;
   long length;
} happy_bday[nSIZE] = {
C_NOTE[0],350, C_NOTE[0],100, D_NOTE[0],500, C_NOTE[0],500, F_NOTE[0],500, E_NOTE[0],900,
C_NOTE[0],350, C_NOTE[0],100, D_NOTE[0],500, C_NOTE[0],500, G_NOTE[0],500, F_NOTE[0],900,
C_NOTE[0],350, C_NOTE[0],100, C_NOTE[1],500, A_NOTE[0],500, F_NOTE[0],500, E_NOTE[0],500, D_NOTE[0],900,
Af_NOTE[0],350, Af_NOTE[0],100, A_NOTE[0],500, F_NOTE[0],500, G_NOTE[0],500, F_NOTE[0],1200};

void do_delay(int ms_delay, int num_ms, int us_delay, int num_us)  
{
 int i;

 for(i=0;i<num_ms;i++)
  delay_ms(250);
 delay_ms(ms_delay);
 for(i=0;i<num_us;i++)
  delay_us(250);
 delay_us(us_delay);
}


void generate_tone(long frequency, long duration)
{
int32 total_delay_time;                      // in microseconds
long TmsD, TusD;
int num_us_delays, num_ms_delays, ms_delay_time, us_delay_time;
long num_periods;

   total_delay_time = (int32)(1000000/frequency)/2-ErrCor; // calculate total delay time (10 for error)
   
   if(total_delay_time>10000)
     return;

   TmsD = total_delay_time/1000; // total delay time of ms
   
   num_ms_delays = TmsD/250;     // number of 250ms delays needed
   
   ms_delay_time = TmsD%250;     // left over ms delay time needed


   TusD = total_delay_time%1000; // total delay time of us (ms already acounted for)

   num_us_delays = TusD/250;     // number of 250us delays needed
   us_delay_time = TusD%250;     // left over us delay time needed

   num_periods = ((unsigned int32)duration*1000)/(1000000/frequency);

   while((num_periods--) != 0)
   {
      do_delay(ms_delay_time, num_ms_delays, us_delay_time, num_us_delays);
      output_high(TONE_PIN);
      do_delay(ms_delay_time, num_ms_delays, us_delay_time, num_us_delays);
      output_low(TONE_PIN);
   }

   return;
}
//*** MAIN ***
void main()
{
int i;

   set_tris_a(0B11111110);
   ErrCor=10;
   for(i=0;i<nSIZE;i++)
   {
    generate_tone(happy_bday[i].tone,happy_bday[i].length);
   }
}