/** Assemble an NMEA GPVTG message and send it out NMEA USARTs.
* NMEA VTG contains course and speed
*
* \param soln Pointer to gnss_solution struct
*/
void nmea_gpvtg(const gnss_solution *soln)
{
/* NMEA Parameters for GPVTG
* Ex.
* $GPVTG,054.7,T,034.4,M,005.5,N,010.2,K
* | | | | | | | | |
* Command | 'T' | 'M' | 'N' | 'K'
* True Course | Speed (K) |
* Mag. course Speed (km/hr)
*/
float vknots, vkmhr;
float x,y,z;
x = soln->vel_ned[0];
y = soln->vel_ned[1];
z = soln->vel_ned[2];
float course = atan2(y,x);
/* Conversion to magnitue knots */
vknots = MS2KNOTTS(x,y,z);
/* Conversion to magnitue km/hr */
vkmhr = MS2KMHR(x,y,z);
NMEA_SENTENCE_START(120);
NMEA_SENTENCE_PRINTF(
"$GPVTG,%05.1f,T," /* Command, course, */
",M," /* Magnetic Course (omitted) */
"%06.2f,N,%06.2f,K", /* Speed (knots, km/hr) */
course* R2D,
vknots, vkmhr);
NMEA_SENTENCE_DONE();
}
/** Assemble an NMEA GPVTG message and send it out NMEA USARTs.
* NMEA VTG contains course and speed
*
* \param nav_meas Pointer to navigation_measurement struct.
* \param soln Pointer to gnss_solution struct
*/
void nmea_gpvtg(const navigation_measurement_t *nav_meas,
const gnss_solution *soln)
{
/* NMEA Parameters for GPVTG
* Ex.
* $GPVTG,054.7,T,034.4,M,005.5,N,010.2,K
* | | | | | | | | |
* Command | 'T' | 'M' | 'N' | 'K'
* True Course | Speed (K) |
* Mag. course Speed (km/hr)
*/
double az, el;
wgsecef2azel(nav_meas[0].sat_pos, soln->pos_ecef, &az, &el);
float vknots, vkmhr;
float x,y,z;
x = soln->vel_ned[0];
y = soln->vel_ned[1];
z = soln->vel_ned[2];
float course = atan2(y,x);
/* Conversion to magnitue knots */
vknots = MS2KNOTTS(x,y,z);
/* Conversion to magnitue km/hr */
vkmhr = MS2KMHR(x,y,z);
char buf[80];
u8 n = sprintf(buf,
"$GPVTG,%05.1f,T," /* Command, course, */
",M," /* Magnetic Course (omitted) */
"%06.2f,N,%06.2f,K", /* Speed (knots, km/hr) */
course* R2D,
vknots, vkmhr);
u8 sum = nmea_checksum(buf);
sprintf(buf + n, "*%02X\r\n", sum);
nmea_output(buf);
}
