Slight fixes before switching to uint64_t and MSB processing.

This commit is contained in:
David E. Tiller 2022-03-30 10:43:02 -04:00
parent 742dfb486b
commit 98b8949f3b
5 changed files with 11 additions and 30 deletions

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@ -23,19 +23,7 @@
* File: eotd.c * File: eotd.c
* *
* Purpose: Functions for processing received EOTD transmissions and * Purpose: Functions for processing received EOTD transmissions and
* converting to NMEA sentence representation. * converting to text format.
*
* References: AIVDM/AIVDO protocol decoding by Eric S. Raymond
* https://gpsd.gitlab.io/gpsd/AIVDM.html
*
* Sample recording with about 100 messages. Test with "atest -B AIS xxx.wav"
* https://github.com/freerange/ais-on-sdr/wiki/example-data/long-beach-160-messages.wav
*
* Useful on-line decoder for AIS NMEA sentences.
* https://www.aggsoft.com/ais-decoder.htm
*
* Future? Add an interface to feed AIS data into aprs.fi.
* https://aprs.fi/page/ais_feeding
* *
*******************************************************************************/ *******************************************************************************/
@ -53,21 +41,21 @@
/*------------------------------------------------------------------- /*-------------------------------------------------------------------
* *
* Convert EOTD binary block (from HDLC frame) to NMEA sentence. * Convert EOTD binary block (from HDLC frame) to text.
* *
* In: Pointer to EOTD binary block and number of bytes. * In: Pointer to EOTD binary block and number of bytes.
* Out: NMEA sentence. Provide size to avoid string overflow. * Out: text.
* *
*--------------------------------------------------------------------*/ *--------------------------------------------------------------------*/
void eotd_to_nmea (unsigned char *eotd, int eotd_len, char *nmea, int nmea_size) void eotd_to_text (unsigned char *eotd, int eotd_len, char *text, int text_size)
{ {
time_t now = time(NULL); time_t now = time(NULL);
*nmea = '\0'; *text = '\0';
strcat(nmea, ctime(&now)); strcat(text, ctime(&now));
for (int i = 0; i < eotd_len; i++) { for (int i = 0; i < eotd_len; i++) {
char temp[32]; char temp[32];
snprintf(temp, sizeof(temp), " %02x", eotd[i]); snprintf(temp, sizeof(temp), " %02x", eotd[i]);
strlcat(nmea, temp, nmea_size); strlcat(text, temp, text_size);
} }
} }

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@ -1 +1 @@
void eotd_to_nmea (unsigned char *ais, int ais_len, char *nema, int nema_size); void eotd_to_text (unsigned char *ais, int ais_len, char *text, int text_size);

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@ -432,7 +432,6 @@ a good modem here and providing a result when it is received.
#define EOTD_PREAMBLE_AND_BARKER_CODE 0x55555712 #define EOTD_PREAMBLE_AND_BARKER_CODE 0x55555712
#define HOTD_PREAMBLE_AND_BARKER_CODE 0x558f1129 #define HOTD_PREAMBLE_AND_BARKER_CODE 0x558f1129
#define EOTD_MAX_LEN 8 #define EOTD_MAX_LEN 8
#undef DUMMY_BIT_HACK
static void eotd_rec_bit (int chan, int subchan, int slice, int raw, int future_use) static void eotd_rec_bit (int chan, int subchan, int slice, int raw, int future_use)
{ {
@ -468,13 +467,6 @@ dw_printf("chan=%d subchan=%d slice=%d raw=%d\n", chan, subchan, slice, raw);
else if (H->eotd_gathering) { else if (H->eotd_gathering) {
H->olen++; H->olen++;
#ifdef DUMMY_BIT_HACK
/* Hack to skip 'dummy' 64th bit */
if (H->olen == 7 && H->frame_len == 7) {
H->eotd_acc <<= 1;
H->olen++;
}
#endif
if (H->olen == 8) { if (H->olen == 8) {
H->olen = 0; H->olen = 0;
char ch = H->eotd_acc & 0xff; char ch = H->eotd_acc & 0xff;

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@ -345,9 +345,9 @@ void multi_modem_process_rec_frame (int chan, int subchan, int slice, unsigned c
} }
else if (save_audio_config_p->achan[chan].modem_type == MODEM_EOTD) { else if (save_audio_config_p->achan[chan].modem_type == MODEM_EOTD) {
char nmea[300]; char nmea[300];
eotd_to_nmea (fbuf, flen, nmea, sizeof(nmea)); eotd_to_text (fbuf, flen, nmea, sizeof(nmea));
char monfmt[276]; char monfmt[276];
snprintf (monfmt, sizeof(monfmt), "EOTD>%s%1d%1d:{%c%c%s", APP_TOCALL, MAJOR_VERSION, MINOR_VERSION, USER_DEF_USER_ID, USER_DEF_TYPE_AIS, nmea); snprintf (monfmt, sizeof(monfmt), "EOTD>%s%1d%1d:{%c%c%s", APP_TOCALL, MAJOR_VERSION, MINOR_VERSION, USER_DEF_USER_ID, USER_DEF_TYPE_EOTD, nmea);
pp = ax25_from_text (monfmt, 1); pp = ax25_from_text (monfmt, 1);
} }
else { else {

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@ -19,3 +19,4 @@
#define USER_DEF_TYPE_AIS 'A' // data type A for AIS NMEA sentence #define USER_DEF_TYPE_AIS 'A' // data type A for AIS NMEA sentence
#define USER_DEF_TYPE_EAS 'E' // data type E for EAS broadcasts #define USER_DEF_TYPE_EAS 'E' // data type E for EAS broadcasts
#define USER_DEF_TYPE_EOTD 'T' // data type T for 'T'rain broadcasts