48 lines
2.3 KiB
C
48 lines
2.3 KiB
C
#ifndef _LIB_FSK_H
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#define _LIB_FSK_H
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#include "../libfm/fm.h"
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typedef struct fsk_mod {
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void *inst;
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int (*send_bit)(void *inst);
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double bits_per_sample; /* fraction of a bit per sample */
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double *sin_tab; /* sine table with correct peak level */
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double phaseshift65536[2]; /* how much the phase of fsk synbol changes per sample */
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double cycles_per_bit65536[2]; /* cycles of one bit */
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double tx_phase65536; /* current transmit phase */
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double level; /* level (amplitude) of signal */
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int ffsk; /* set, if FFSK TX mode */
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double f0_deviation; /* deviation of frequencies, relative to center */
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double f1_deviation;
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int low_bit, high_bit; /* a low or high deviation means which bit? */
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int tx_bit; /* current transmitting bit (-1 if not set) */
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double tx_bitpos; /* current transmit position in bit */
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int filter; /* set, if filters are used */
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iir_filter_t lp[2]; /* filter to smooth transmission spectrum */
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} fsk_mod_t;
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typedef struct fsk_demod {
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void *inst;
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void (*receive_bit)(void *inst, int bit, double quality, double level);
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fm_demod_t demod;
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double bits_per_sample; /* fraction of a bit per sample */
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double f0_deviation; /* deviation of frequencies, relative to center */
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double f1_deviation;
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int low_bit, high_bit; /* a low or high deviation means which bit? */
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int rx_bit; /* current receiving bit (-1 if not yet measured) */
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double rx_bitpos; /* current receive position in bit (sampleclock) */
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double rx_bitadjust; /* how much does a bit change cause the sample clock to be adjusted in phase */
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int rx_change; /* set, if we have a level change before sampling the bit */
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} fsk_demod_t;
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int fsk_mod_init(fsk_mod_t *fsk, void *inst, int (*send_bit)(void *inst), int samplerate, double bitrate, double f0, double f1, double level, int coherent, int filter);
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void fsk_mod_cleanup(fsk_mod_t *fsk);
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int fsk_mod_send(fsk_mod_t *fsk, sample_t *sample, int length, int add);
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void fsk_mod_tx_reset(fsk_mod_t *fsk);
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int fsk_demod_init(fsk_demod_t *fsk, void *inst, void (*receive_bit)(void *inst, int bit, double quality, double level), int samplerate, double bitrate, double f0, double f1, double bitadjust);
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void fsk_demod_cleanup(fsk_demod_t *fsk);
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void fsk_demod_receive(fsk_demod_t *fsk, sample_t *sample, int length);
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#endif /* _LIB_FSK_H */
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