mirror
/
RS-tracker
kopia lustrzana https://github.com/rs1729/RS
1
0
Forkuj 0
Kod Zgłoszenia Projekty Wydania Wiki Aktywność

meisei ims100: inner gps checksum

pull/18/head
Zilog80 2019-09-10 22:07:58 +02:00
rodzic 11a884103d
commit 99922ba515
2 zmienionych plików z 39 dodań i 4 usunięć
Pokaż statystyki Ściągnij plik aktualizacji Ściągnij plik porównania Expand all files Collapse all files

20
demod/mod/meisei100mod.c
Wyświetl plik

@ -193,6 +193,11 @@ static ui32_t bits2val(ui8_t bits[], int len) {
return val;
}
static int get_w16(ui8_t *subframe_bits, int j) {
if (j < 0 || j > 11) return -1;
return bits2val(subframe_bits+HEADLEN+46*(j/2)+17*(j%2), 16);
}
/* -------------------------------------------------------------------------- */
@ -218,6 +223,8 @@ int main(int argc, char **argv) {
int subframe = 0;
int err_frm = 0;
int gps_chk_sum = 0;
int gps_err = 0;
ui8_t block_err[6];
int block;
@ -431,6 +438,8 @@ int main(int argc, char **argv) {
biphi_s(gpx.frame_rawbits, gpx.frame_bits+HEADLEN);
gps_chk_sum = 0;
gps_err = 0;
err_frm = 0;
for (subframe = 0; subframe < 2; subframe++)
@ -554,6 +563,9 @@ int main(int argc, char **argv) {
ui32_t w32;
float *fcfg = (float *)&w32;
// 1st subframe
for (j = 10; j < 12; j++) gps_chk_sum += get_w16(subframe_bits, j);
// 0x30C1, 0x31C1
val = bits2val(subframe_bits+HEADLEN+46*3+17, 16);
if ( (val & 0xFF) < 0xC0 && err_frm == 0) {
@ -599,6 +611,10 @@ int main(int argc, char **argv) {
if (header_found % 2 == 0) // FB6230
{
// 2nd subframe
for (j = 0; j < 11; j++) gps_chk_sum += get_w16(subframe_bits, j);
gps_err = (gps_chk_sum & 0xFFFF) != get_w16(subframe_bits, 11); // 1st+2nd subframe
if ((counter % 2 == 0)) {
//offset=24+16+1;
@ -646,7 +662,7 @@ int main(int argc, char **argv) {
if (counter % 2 == 0) {
if (option_ecc) {
printf(" ");
if (gps_err) printf("(no)"); else printf("(ok)");
if (err_frm) printf("[NO]"); else printf("[OK]");
}
if (option_verbose) {
@ -661,7 +677,7 @@ int main(int argc, char **argv) {
}
printf("\n");
if (option_jsn && err_frm==0) {
if (option_jsn && err_frm==0 && gps_err==0) {
char id_str[] = "xxxxxx\0\0\0\0\0\0";
if (gpx.sn > 0 && gpx.sn < 1e9) {
sprintf(id_str, "%.0f", gpx.sn);

23
meisei/meisei_ims.c
Wyświetl plik

@ -64,6 +64,9 @@ Variante 2 (iMS-100 ?)
0x1B..0x1D HEADER 0xFB6230
0x22..0x23 yy00..yy03 (yy00: GPS PRN?)
iMS-100 GPS checksum
049DCE[10] + 049DCE[11] + FB6230[0] + .. + FB6230[10] == FB6230[11] (mod 0x10000)
Die 46bit-Bloecke sind BCH-Codewoerter. Es handelt sich um einen (63,51)-Code mit Generatorpolynom
x^12+x^10+x^8+x^5+x^4+x^3+1;
@ -439,6 +442,11 @@ ui32_t bits2val(ui8_t bits[], int len) {
return val;
}
int get_w16(int j) {
if (j < 0 || j > 11) return -1;
return bits2val(subframe_bits+HEADLEN+46*(j/2)+17*(j%2), 16);
}
/* -------------------------------------------------------------------------- */
@ -452,6 +460,8 @@ int main(int argc, char **argv) {
bit, len;
int subframe = 0;
int err_frm = 0;
int gps_chk_sum = 0;
int gps_err = 0;
int counter;
ui32_t val;
@ -608,6 +618,8 @@ int main(int argc, char **argv) {
biphi_s(frame_rawbits, frame_bits+HEADLEN);
gps_chk_sum = 0;
gps_err = 0;
err_frm = 0;
for (subframe = 0; subframe < 2; subframe++)
@ -725,6 +737,9 @@ int main(int argc, char **argv) {
ui32_t w32;
float *fcfg = (float *)&w32;
// 1st subframe
for (j = 10; j < 12; j++) gps_chk_sum += get_w16(j);
// 0x30C1, 0x31C1
val = bits2val(subframe_bits+HEADLEN+46*3+17, 16);
if ( (val & 0xFF) < 0xC0 && err_frm == 0) {
@ -770,6 +785,10 @@ int main(int argc, char **argv) {
if (header_found % 2 == 0) // FB6230
{
// 2nd subframe
for (j = 0; j < 11; j++) gps_chk_sum += get_w16(j);
gps_err = (gps_chk_sum & 0xFFFF) != get_w16(11); // 1st+2nd subframe
if ((counter % 2 == 0)) {
//offset=24+16+1;
@ -817,7 +836,7 @@ int main(int argc, char **argv) {
if (counter % 2 == 0) {
if (option_ecc) {
printf(" ");
if (gps_err) printf("(no)"); else printf("(ok)");
if (err_frm) printf("[NO]"); else printf("[OK]");
}
if (option_verbose) {
@ -832,7 +851,7 @@ int main(int argc, char **argv) {
}
printf("\n");
if (option_jsn && err_frm==0) {
if (option_jsn && err_frm==0 && gps_err==0) {
char id_str[] = "xxxxxx\0\0\0\0\0\0";
if (gpx.sn > 0 && gpx.sn < 1e9) {
sprintf(id_str, "%.0f", gpx.sn);