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//file pwmsine8bit.c

//generate 8 bit sinewave using wavetable lookup

//12khz sample rate, 62500 hz pwm on pd5 oc1a

//for ere co embmega32 16Mhz 38400

//May 3 07 Bob G initial edit 8 bit

//May 5 07 Bob G add traffic tones

//Jan 18 08 Bob G compile with 7.15

//#include <stdio.h>

//#include <stdlib.h>

#include <ctype.h>

#include <math.h>   //sin

#include <avr/io.h>

#include <avr/interrupt.h>

#include <avr/pgmspace.h>

#include <util/delay.h>

#include <string.h>

#include <stdint.h>

#include "../timer/timer.h"

#include "../main.h"

#ifdef USE_SOUND

#define INTR_OFF() asm("CLI")

#define INTR_ON()  asm("SEI")

//------vars in bss-------

volatile unsigned char sindat[256]; //8 bit sine table

//unsigned int addat[8];    //internal 10 bit

unsigned int    idesfreq;

unsigned char   iattenfac; //0-255

unsigned char   dispon;

unsigned char   freqincipart,freqincfpart;

unsigned char   waveptipart,waveptfpart;

unsigned char   tics;

unsigned char   generate;

float basefreq;

float freqratio;

float sampfreq;  //12khz

float samppd;    //83.33usec

float fdesfreq;

float attendb;   //0-50

float attenfac;  //.999-0

const float pi=3.141592654;

#define MSB(w) ((char*) &w)[1]

#define LSB(w) ((char*) &w)[0]

#define TONE_BUFFER_SIZE 64

#define TONE_BUFFER_MASK ( TONE_BUFFER_SIZE - 1)

static volatile unsigned char ToneBuf[TONE_BUFFER_SIZE];

static volatile unsigned char ToneBufHead;

static volatile unsigned char ToneBufTail;

//-------------------------------

void cvtfreq2frac(void){

//calc freq ratio, separate into integer and fractional parts

  fdesfreq=idesfreq;

  freqratio=fdesfreq/basefreq;               //calc freq ratio from basefreq

  freqincipart=(int)freqratio;               //calc integer part

  freqincfpart=(freqratio-freqincipart)*256; //calc fractional part

//  cprintf("ipart %02x  fpart %02x\n",freqincipart,freqincfpart);  

}

//-------------------------------

void cvtdb2fac(void){

//cvt db to attenuation factor

  attenfac=pow(10.0,-attendb/20.0); //10^0=1

  iattenfac=(unsigned char)(attenfac*255.0);

//  cprintf("attenfac %#7.5f\n",attenfac);

//  cprintf("iattenfac %02x\n",iattenfac);

}

//-------------------------

void initsindat(void){

//init 8 bit signed sin table 0-ff in ram 36dB s/n   46Hz basefreq

unsigned int n;

  for(n=0; n < 256; n++){

    sindat[n]=(signed char)127.0*sin(2.0*pi*n/256.0); //256 sin points

  }

}

//-------------------------

void initvars(void){

//init vars

//  sampfreq=12000.0;    //hz

  sampfreq=19530.0;    //hz

//  printf("samp freq %#7.1f hz\n\r",sampfreq);

//  printf("samp freq %#7.1f hz\n\r",1234567.1);

  samppd=1.0/sampfreq; //83.33usec

//  printf("samppd %#7.1f usec \n\r",samppd*1e6);

  basefreq=sampfreq/256.0; //46.875hz

//  printf("basefreq %#7.5f hz\n\r",basefreq);

  idesfreq=400;

  cvtfreq2frac();

  cvtdb2fac(); //0db =.9999= 0xff

}

//---------------------

void tone1(int hz)

//tone at hz for ms

{

  uint8_t volume = 0;

//  TCNT2=0;

//  sound_timer = ms/5;

//  soundpause_timer = soundpause/5;

  idesfreq=hz;

  cvtfreq2frac();

  attendb=volume;

  cvtdb2fac();

  if (hz ==0) generate=0;

   else { generate = 1;

//          TIMSK2 |= _BV(TOIE2);          // Interrupt freigeben

        }

}

//-------------------------------

void tone_handler(void)  // wird aus Timerinterrupt aufgerufen

{

  uint16_t f_Hz=0;

  uint16_t dur_ms=0;

  char volume=0;

  char tmp_high = 0;

  char tmp_low = 0;

  unsigned char tmptail;

    if ( ToneBufHead != ToneBufTail) {

        /* calculate and store new buffer index */

        tmptail = (ToneBufTail + 1) & TONE_BUFFER_MASK;

        ToneBufTail = tmptail;

        /* get one byte from buffer */

        tmp_low = ToneBuf[tmptail];  /* f_Hz low */

    }else{

        return;

    }

    if ( ToneBufHead != ToneBufTail) {

        /* calculate and store new buffer index */

        tmptail = (ToneBufTail + 1) & TONE_BUFFER_MASK;

        ToneBufTail = tmptail;

        /* get one byte from buffer */

        tmp_high = ToneBuf[tmptail];  /* f_Hz high */

    }else{

        return;

    }

      f_Hz = (((uint16_t) tmp_high) << 8) | tmp_low;

      if ( ToneBufHead != ToneBufTail) {

          /* calculate and store new buffer index */

          tmptail = (ToneBufTail + 1) & TONE_BUFFER_MASK;

          ToneBufTail = tmptail;

          /* get one byte from buffer*/

          volume = ToneBuf[tmptail];  /* volume */

      }else{

          return;

      }

      if ( ToneBufHead != ToneBufTail) {

          /* calculate and store new buffer index */

          tmptail = (ToneBufTail + 1) & TONE_BUFFER_MASK;

          ToneBufTail = tmptail;

          /* get one byte from buffer */

          tmp_low = ToneBuf[tmptail];  /* low Duratuion */

      }else{

          return;

      }

      if ( ToneBufHead != ToneBufTail) {

          /* calculate and store new buffer index */

          tmptail = (ToneBufTail + 1) & TONE_BUFFER_MASK;

          ToneBufTail = tmptail;

          /* get one byte from buffer*/

          tmp_high = ToneBuf[tmptail];  /* high Duration */

      }else{

          return;

      }

      dur_ms = (((uint16_t) tmp_high) << 8) | tmp_low;

      sound_timer = dur_ms/10;

//      TCNT2=0;

      idesfreq= f_Hz;

      cvtfreq2frac();

      attendb= volume;

      cvtdb2fac();

      if (f_Hz ==0) generate=0;

       else { generate = 1;

//              TIMSK2 |= _BV(TOIE2);          // Interrupt freigeben

       }

//      printf("tone_handler f_Hz: %i dur_ms: %i volume: %i\n\r", f_Hz,dur_ms,volume);

}

void tone_putc(unsigned char data)

{

    unsigned char tmphead;

    tmphead  = (ToneBufHead + 1) & TONE_BUFFER_MASK;

    while ( tmphead == ToneBufTail ){

        ;/* wait for free space in buffer */

    }

    ToneBuf[tmphead] = data;

    ToneBufHead = tmphead;

}/* tone_putc */

void playTone(uint16_t f_Hz, uint16_t dur_ms, uint8_t volume)

 {

//  printf("Playtone f_Hz: %i dur_ms: %i volume: %i\n\r", f_Hz,dur_ms,volume);

  tone_putc(LSB(f_Hz));

  tone_putc( MSB(f_Hz));

  tone_putc( volume);

  tone_putc(LSB(dur_ms));

  tone_putc(MSB(dur_ms));

 }

//-----------------

void InitSound(void){//main program

  ToneBufHead = 0;

  ToneBufTail = 0;

  initvars();

  initsindat();

  Timer2_Init();

  Timer3_Init();

}

#endif