bool ubloxNMEA::parsePUBX_00( char chr )
{
bool ok = true;
switch (fieldIndex) {
case 1:
// The first field is actually a message subtype
if (chrCount == 0)
ok = (chr == '0');
else if (chrCount == 1) {
switch (chr) {
#if defined(NMEAGPS_PARSE_PUBX_00) | defined(NMEAGPS_RECOGNIZE_ALL)
case '0': break;
#endif
#if defined(NMEAGPS_PARSE_PUBX_04) | defined(NMEAGPS_RECOGNIZE_ALL)
case '4': nmeaMessage = (nmea_msg_t) PUBX_04; break;
#endif
default : ok = false;
}
} else // chrCount > 1
ok = (chr == ',');
break;
#ifdef NMEAGPS_PARSE_PUBX_00
case 2: return parseTime( chr );
PARSE_LOC(3);
case 7: return parseAlt( chr );
case 8: return parseFix( chr );
case 11: return parseSpeed( chr ); // kph!
case 12: return parseHeading( chr );
case 15: return parseHDOP( chr );
case 16: return parseVDOP( chr );
case 18: return parseSatellites( chr );
#endif
}
return ok;
} // parsePUBX_00
bool ubloxNMEA::parsePUBX_00( char chr )
{
bool ok = true;
switch (fieldIndex) {
case 1:
// The first field is actually a message subtype
if (chrCount == 0)
ok = (chr == '0');
else if (chrCount == 1) {
switch (chr) {
#if defined(NMEAGPS_PARSE_PUBX_00) | defined(NMEAGPS_RECOGNIZE_ALL)
case '0': break;
#endif
#if defined(NMEAGPS_PARSE_PUBX_04) | defined(NMEAGPS_RECOGNIZE_ALL)
case '4': nmeaMessage = (nmea_msg_t) PUBX_04; break;
#endif
default : ok = false;
}
} else // chrCount > 1
ok = (chr == ',');
break;
#ifdef NMEAGPS_PARSE_PUBX_00
case 2: return parseTime( chr );
PARSE_LOC(3);
case 7: return parseAlt( chr );
case 8: return parseFix( chr );
case 9: // use Horizontal accuracy for both lat and lon errors
#if defined(GPS_FIX_LAT_ERR)
ok = parse_lat_err( chr );
#if defined(GPS_FIX_LON_ERR)
// When the lat_err field is finished,
// copy it to the lon_err field.
if (chr == ',') {
m_fix.valid.lon_err = m_fix.valid.lat_err;
if (m_fix.valid.lon_err)
m_fix.lon_err_cm = m_fix.lat_err_cm;
}
#endif
#elif defined(GPS_FIX_LON_ERR)
ok = parse_lon_err( chr );
#endif
break;
case 10: return parse_alt_err( chr ); // vertical accuracy
case 11:
#ifdef GPS_FIX_SPEED
ok = parseSpeed( chr ); // PUBX,00 provides speed in km/h!
if ((chr == ',') && m_fix.valid.speed) {
uint32_t kph = m_fix.spd.int32_000();
uint32_t nmiph = (kph * 1000) / gps_fix::M_PER_NMI;
m_fix.spd.whole = nmiph / 1000;
m_fix.spd.frac = (nmiph - m_fix.spd.whole*1000);
// Convert to Nautical Miles/Hour
}
#endif
break;
case 12: return parseHeading( chr );
case 13: return parseVelocityDown( chr );
case 15: return parseHDOP( chr );
case 16: return parseVDOP( chr );
case 18: return parseSatellites( chr );
#endif
}
return ok;
} // parsePUBX_00
/*****************************************************************************
** Function name: GPSRetreiveData
**
** Descriptions: Reads and parses the next set of GPS data.
**
** parameters: None
** Returned value: The parsed information
**
*****************************************************************************/
const gpsData* GPSRetreiveData(void)
{
uint8_t * pattern = (uint8_t*)"GPGGA";
while (1) {
uint8_t buf[100];
uint8_t ch = 0;
uint8_t *ptr = 0;
int index = 0;
// Retrieve the first byte
if (!UARTGetChar(&ch))
continue;
// look for "$GPGGA," header
if (ch != '$') {
continue;
}
// Retrieve the next six bytes
for (index=0; index<6; index++) {
buf[index] = UARTGetCharBlock();
}
//Check if its Global Positioning System fixed Data
if(hasPattern((uint8_t*)&buf, pattern) == 0) {
continue;
}
//Retrieve the data from the GPS module
for (index=0; index<100; index++) {
buf[index] = UARTGetCharBlock();
if (buf[index] == '\r') {
buf[index] = END_OF_MESSAGE;
break;
}
}
ptr = &buf[0];
//parse UTC time
parseUTC(&ptr);
//parse Latitude
parseLatitude(&ptr);
// parse N/S field
parseNSIndicator(&ptr);
// parse Longitude
parseLongitude(&ptr);
// parse E/W field
parseEWIndicator(&ptr);
// parse fix position
parseFixIndicator(&ptr);
// parse satellites
parseSatellites(&ptr);
// parse horizontal-dilution-of-precision field
parseHDOP(&ptr);
// parse altitude
parseAltitudes(&ptr);
break;
}
return &data;
}
