fskmodem.h File Reference

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	fsk_data
Defines
#define	PARITY_NONE   0
#define	PARITY_EVEN   1
#define	PARITY_ODD   2
#define	NCOLA   0x4000
Functions
int	fsk_serie (fsk_data *fskd, short *buffer, int *len, int *outbyte)

---

Define Documentation

#define NCOLA   0x4000

Definition at line 25 of file fskmodem.h.

#define PARITY_EVEN   1

Definition at line 21 of file fskmodem.h.

#define PARITY_NONE   0

Definition at line 20 of file fskmodem.h.

#define PARITY_ODD   2

Definition at line 22 of file fskmodem.h.

---

Function Documentation

int fsk_serie (  fsk_data *  fskd, short *  buffer, int *  len, int *  outbyte )

Definition at line 183 of file fskmodem.c. References GET_SAMPLE, fsk_data::spb, fsk_data::state, STATE_SEARCH_STARTBIT2, STATE_SEARCH_STARTBIT3, fsk_data::x1, and fsk_data::x2. Referenced by callerid_feed(), and tdd_feed(). { /* this was jesus's nice, reasonable, working (at least with RTTY) code to look for the beginning of the start bit. Unfortunately, since TTY/TDD's just start sending a start bit with nothing preceding it at the beginning of a transmission (what a LOSING design), we cant do it this elegantly */ /* if (demodulador(zap,&x1)) return(-1); for(;;) { if (demodulador(zap,&x2)) return(-1); if (x1>0 && x2<0) break; x1=x2; } */ /* this is now the imprecise, losing, but functional code to detect the beginning of a start bit in the TDD sceanario. It just looks for sufficient level to maybe, perhaps, guess, maybe that its maybe the beginning of a start bit, perhaps. This whole thing stinks! */ if (demodulador(fskd,&fskd->x1,GET_SAMPLE)) return(-1); samples++; for(;;) { search_startbit2: if (!*len) { fskd->state = STATE_SEARCH_STARTBIT2; return 0; } samples++; if (demodulador(fskd,&fskd->x2,GET_SAMPLE)) return(-1); #if 0 printf("x2 = %5.5f ", fskd->x2); #endif if (fskd->x2 < -0.5) break; } search_startbit3: /* Esperamos 0.5 bits antes de usar DPLL */ i=fskd->spb/2; if (*len < i) { fskd->state = STATE_SEARCH_STARTBIT3; return 0; } for(;i;i--) { if (demodulador(fskd,&fskd->x1,GET_SAMPLE)) return(-1); #if 0 printf("x1 = %5.5f ", fskd->x1); #endif samples++; } /* x1 debe ser negativo (confirmación del bit de start) */ } while (fskd->x1>0); fskd->state = STATE_GET_BYTE; getbyte: /* Need at least 80 samples (for 1200) or 1320 (for 45.5) to be sure we'll have a byte */ if (fskd->nbit < 8) { if (*len < 1320) return 0; } else { if (*len < 80) return 0; } /* Leemos ahora los bits de datos */ j=fskd->nbit; for (a=n1=0;j;j--) { olen = *len; i=get_bit_raw(fskd, buffer, len); buffer += (olen - *len); if (i == -1) return(-1); if (i) n1++; a>>=1; a|=i; } j=8-fskd->nbit; a>>=j; /* Leemos bit de paridad (si existe) y la comprobamos */ if (fskd->paridad) { olen = *len; i=get_bit_raw(fskd, buffer, len); buffer += (olen - *len); if (i == -1) return(-1); if (i) n1++; if (fskd->paridad==1) { /* paridad=1 (par) */ if (n1&1) a|=0x100; /* error */ } else { /* paridad=2 (impar) */ if (!(n1&1)) a|=0x100; /* error */ } } /* Leemos bits de STOP. Todos deben ser 1 */ for (j=fskd->nstop;j;j--) { r = get_bit_raw(fskd, buffer, len); if (r == -1) return(-1); if (!r) a|=0x200; } /* Por fin retornamos */ /* Bit 8 : Error de paridad */ /* Bit 9 : Error de Framming */ *outbyte = a; fskd->state = STATE_SEARCH_STARTBIT; return 1; } }

---