diff options
| -rw-r--r-- | src/fl2k_garage.c | 92 |
1 files changed, 57 insertions, 35 deletions
diff --git a/src/fl2k_garage.c b/src/fl2k_garage.c index 6eb0057..575c3ad 100644 --- a/src/fl2k_garage.c +++ b/src/fl2k_garage.c @@ -54,7 +54,7 @@ #define BUFFER_SAMPLES (1 << BUFFER_SAMPLES_SHIFT) #define BUFFER_SAMPLES_MASK ((1 << BUFFER_SAMPLES_SHIFT)-1) -#define AUDIO_BUF_SIZE 1024 +#define AUDIO_BUF_SIZE 4096 #define BASEBAND_SAMPLES_PER_CHIP 3 #define BASEBAND_WORD_BITS 12 @@ -63,6 +63,7 @@ #define BASEBAND_CHIPS_PER_SPACE BASEBAND_CHIPS_PER_WORD #define BASEBAND_SPACE_HIGH_CHIPS 1 #define BASEBAND_SPACE_LOW_CHIPS (BASEBAND_CHIPS_PER_SPACE - BASEBAND_SPACE_HIGH_CHIPS) +#define BASEBAND_CHIPS_TOTAL (BASEBAND_CHIPS_PER_SPACE + BASEBAND_CHIPS_PER_WORD) fl2k_dev_t *dev = NULL; int do_exit = 0; @@ -76,7 +77,9 @@ pthread_cond_t cb_cond; pthread_cond_t fm_cond; pthread_cond_t am_cond; -FILE *file; +int16_t *sample_buf; +int sample_buf_size; + int8_t *txbuf = NULL; int8_t *ambuf = NULL; int8_t *buf1 = NULL; @@ -313,6 +316,7 @@ void am_modulator(const int code_input) int32_t lastamp = 0; uint32_t lastwritepos = writepos; int16_t sample = 0; + int samplebuf_pos = 0; /* * 3*640 us = 1,92 ms pro Symbol @@ -329,36 +333,11 @@ void am_modulator(const int code_input) do_exit = 1; for (i = 0; i < len; i++) { - if( ++b >= BASEBAND_SAMPLES_PER_CHIP ){ - b = 0; - if(counter < (BASEBAND_SPACE_LOW_CHIPS)){ - sample = 0; - } - else if(counter < (BASEBAND_CHIPS_PER_SPACE)){ - // synch symbol - sample = 1; - // reload code - code = code_input; - } - else{ - int m; - m = counter % BASEBAND_CHIPS_PER_BIT; - if(m == 0){ - sample = 0; - } - else if(m == 1){ - sample = (code & 1) ^ 1; - } - else{ - sample = 1; - code >>= 1; - } - } - if(++counter >= (BASEBAND_CHIPS_PER_SPACE + BASEBAND_CHIPS_PER_WORD)){ - counter = 0; - } - } /* Modulate and buffer the sample */ + sample = sample_buf[samplebuf_pos++]; + if(samplebuf_pos >= BASEBAND_SAMPLES_PER_CHIP * BASEBAND_CHIPS_TOTAL){ + samplebuf_pos = 0; + } lastamp = modulate_sample_am(lastwritepos, lastamp, sample); lastwritepos = writepos++; writepos %= BUFFER_SAMPLES; @@ -369,6 +348,49 @@ void am_modulator(const int code_input) } } +void prepare_baseband(const int code_input, int16_t * sbuf){ + int counter; + int b; + int sample_no; + int16_t sample; + int msb_first_code; + + msb_first_code = 0; + // change to msb first and invert + for(b = 0;b<12;b++){ + msb_first_code |= code_input & (1<<b) ? 0 : 1; + msb_first_code <<= 1; + } + + sample_no = 0; + for(counter=0;counter < (BASEBAND_CHIPS_PER_SPACE + BASEBAND_CHIPS_PER_WORD) ; counter++){ + for(b=0 ; b<BASEBAND_SAMPLES_PER_CHIP ; b++){ + if(counter < (BASEBAND_SPACE_LOW_CHIPS)){ + sample = 0; + } + else if(counter < (BASEBAND_CHIPS_PER_SPACE)){ + // synch symbol + sample = 1; + } + else{ + int m; + m = counter % BASEBAND_CHIPS_PER_BIT; + if(m == 0){ + sample = 0; + } + else if(m == 1){ + sample = (msb_first_code & 1); + } + else{ + sample = 1; + msb_first_code >>= 1; + } + } + sbuf[counter * BASEBAND_SAMPLES_PER_CHIP + b] = sample; + } + } +} + void fl2k_callback(fl2k_data_info_t *data_info) { if (data_info->device_error) { @@ -453,6 +475,7 @@ int main(int argc, char **argv) slopebuf = malloc(BUFFER_SAMPLES * sizeof(double)); ampbuf = malloc(BUFFER_SAMPLES * sizeof(double)); slopebuf = malloc(BUFFER_SAMPLES * sizeof(double)); + sample_buf = malloc(BASEBAND_SAMPLES_PER_CHIP * BASEBAND_CHIPS_TOTAL); readpos = 0; writepos = 1; @@ -470,6 +493,8 @@ int main(int argc, char **argv) pthread_cond_init(&am_cond, NULL); pthread_attr_init(&attr); + prepare_baseband(code, sample_buf); + fl2k_open(&dev, (uint32_t)dev_index); if (NULL == dev) { fprintf(stderr, "Failed to open fl2k device #%d.\n", dev_index); @@ -495,7 +520,7 @@ int main(int argc, char **argv) /* Calculate needed constants */ carrier_per_signal = (int)((double) samp_rate * chiptime_us/(1000000*BASEBAND_SAMPLES_PER_CHIP) + 0.5); - printf("Cps : %d\n", carrier_per_signal); + printf("Cps :\t%d\n", carrier_per_signal); #ifndef _WIN32 sigact.sa_handler = sighandler; sigemptyset(&sigact.sa_mask); @@ -514,9 +539,6 @@ int main(int argc, char **argv) out: fl2k_close(dev); - if (file != stdin) - fclose(file); - free(ampbuf); free(slopebuf); free(buf1); |