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P25p2 -- Harris GPS vPDU (WIP);

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lwvmobile
2023-12-04 07:39:57 -05:00
parent dda84e74bc
commit e5dd5eed5d
2 changed files with 125 additions and 2 deletions
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4
src/p25_lcw.c
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@@ -528,8 +528,8 @@ void apx_embedded_gps (dsd_opts * opts, dsd_state * state, uint8_t lc_bits[])
if (opts->lrrp_file_output == 1)
{
int src = 0;
if (slot == 0) src = state->lasttg;
if (slot == 1) src = state->lasttgR;
if (slot == 0) src = state->lastsrc;
if (slot == 1) src = state->lastsrcR;
//open file by name that is supplied in the ncurses terminal, or cli
pFile = fopen (opts->lrrp_out_file, "a");

123
src/p25p2_vpdu.c
View File

@@ -35,6 +35,96 @@ static const uint8_t mac_msg_len[256] = {
//TODO: Check for Non standard MFIDs first MAC[1], then set len on the MAC[2] if
//the result from the len table is 0 (had to manually enter a few observed values from Harris)
void harris_gps(dsd_opts * opts, dsd_state * state, int slot, uint8_t * input)
{
uint8_t lat_sign, lat_deg, lat_min = 0;
uint8_t lon_sign, lon_deg, lon_min = 0;
uint16_t lat_mmin = 0;
uint16_t lon_mmin = 0;
//potentially in this PDU, but unverifiable without documentation or reasonable proof
uint16_t speed = 0; UNUSED(speed);
uint16_t angle = 0; UNUSED(angle);
//unknown location, if it actually exists here, or units of measurement
speed = (uint16_t)ConvertBitIntoBytes(&input[128], 8); //number of significant bits?
angle = (uint16_t)ConvertBitIntoBytes(&input[136], 8); //number of significant bits?
float lat_dec = 0.0f;
float lon_dec = 0.0f;
char latord[3];
char lonord[3];
sprintf (latord, "%s", "N");
sprintf (lonord, "%s", "E");
char deg_glyph[4];
sprintf (deg_glyph, "%s", "°");
//This appears to be similar to the NMEA GPGGA format (DDmm.mm) but
//octets are ordered in least significant to most significant value
lat_mmin = (uint16_t)ConvertBitIntoBytes(&input[40], 16); //? bits required, but grabbing two octets
lat_min = (uint8_t)ConvertBitIntoBytes(&input[58], 6); //6 bits required to get 60
lat_deg = (uint8_t)ConvertBitIntoBytes(&input[65], 7); //7 bits required to get 90
lat_sign = input[72]; //64
lon_mmin = (uint16_t)ConvertBitIntoBytes(&input[72], 16); //? bits required, but grabbing two octets
lon_min = (uint8_t)ConvertBitIntoBytes(&input[90], 6); //6 bits required to get 60 (could also include the 4 bits starting at 86)
lon_deg = (uint8_t)ConvertBitIntoBytes(&input[96], 8); //8 bits required to get 180
lon_sign = input[88]; //88, unsure of a correct location, but on the sample with 0 minutes, this lonely bit was flagged on
//unused, maybe we will use them still somehow if we also display ddmmss format
if (lat_sign)
sprintf (latord, "%s", "S");
if (lon_sign)
sprintf (lonord, "%s", "W");
//calculate decimal representation (was a pain to figure out the sub minute values)
lat_dec = ( (float)lat_deg + ((float)lat_min/60.0f) + ((float)lat_mmin/600000.0f) );
lon_dec = ( (float)lon_deg + ((float)lon_min/60.0f) + ((float)lon_mmin/600000.0f) );
if (lat_sign)
lat_dec *= -1.0f;
if (lon_sign)
lon_dec *= -1.0f;
fprintf (stderr, " GPS: %f%s, %f%s", lat_dec, deg_glyph, lon_dec, deg_glyph);
// fprintf (stderr, " Speed: %d kph; Track: %d%s;", speed, angle, deg_glyph);
//line break
fprintf (stderr, "\n");
//save to array for ncurses
sprintf (state->dmr_embedded_gps[slot], "GPS: (%f%s, %f%s)", lat_dec, deg_glyph, lon_dec, deg_glyph);
//save to LRRP report for mapping/logging
FILE * pFile; //file pointer
if (opts->lrrp_file_output == 1)
{
int src = 0;
if (slot == 0) src = state->lastsrc;
if (slot == 1) src = state->lastsrcR;
//open file by name that is supplied in the ncurses terminal, or cli
pFile = fopen (opts->lrrp_out_file, "a");
fprintf (pFile, "%s\t", getDateL() );
fprintf (pFile, "%s\t", getTimeL() );
fprintf (pFile, "%08d\t", src);
fprintf (pFile, "%.5lf\t", lat_dec);
fprintf (pFile, "%.5lf\t", lon_dec);
fprintf (pFile, "0\t " ); //zero for velocity
fprintf (pFile, "0\t " ); //zero for azimuth
fprintf (pFile, "\n");
fclose (pFile);
}
//NOTE: There are quite a few left over octets, 10?, (not including potential speed/angle)
//so, plenty of space for other information, currently unknown what that would be
}
void process_MAC_VPDU(dsd_opts * opts, dsd_state * state, int type, unsigned long long int MAC[24])
{
//handle variable content MAC PDUs (Active, Idle, Hangtime, or Signal)
@@ -1768,6 +1858,39 @@ void process_MAC_VPDU(dsd_opts * opts, dsd_state * state, int type, unsigned lon
}
//This is now confirmed to have the Harris Talker GPS, but the structure is unusual compared to other MFID messages,
//the A4 indicator is one octet more to the 'right' than is normative, so I cannot verify the len value (0x11, or 17).
//Its possible the 0x80 is the 'Manufacturer Message' Opcode, which in the manual shows the rest of the
//octets are not normative, and as such, can't say there is a len value (but should assume entire the SACCH/FACCH field)
if (MAC[len_a+1] == 0x80 && MAC[len_a+2] != 0xA4 && MAC[len_a+2] != 0x90)
{
int unk1 = MAC[len_a+1]; //assuming this is the octet set for the 'manufacturer specific' message, may only be the MSBit
int unk2 = MAC[len_a+2]; //This field is observed as 0xAA, unknown if this is an opcode, or other MFID
int mfid = MAC[len_a+3]; //This is where the 0xA4 (Harris) Identifier is found in this message, as opposed to +2
int len = MAC[len_a+4]; //0x11 or 17 dec sounds reasonable, but cannot verify
fprintf (stderr, "\n MFID %02X (Harris); Len: %d; Opcode: %02X/%02X;", mfid, len, unk1, unk2);
//convert bytes to bits, may move this up top
uint8_t mac_bits[24*8];
memset (mac_bits, 0, sizeof(mac_bits));
int l, x, z = 0;
for (l = 0; l < 24; l++)
{
for (x = 0; x < 8; x++)
mac_bits[z++] = (((uint8_t)MAC[l] << x) & 0x80) >> 7;
}
harris_gps (opts, state, slot, mac_bits);
//debug - just dump payload
for (i = 0; i < 24; i++)
fprintf (stderr, " %02llX", MAC[i]);
fprintf(stderr, "\n DEV NOTE: If you see this message, but incorrect lat/lon,\n please submit samples to https://github.com/lwvmobile/dsd-fme/issues");
len_b = 17;
}
/*
Maybe this is why some of these SYNC_BCST PDUs have zeroes in most fields