Garmin GPS 19x HVS Technical Specifications page 26

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Position Record
The Position Record has a record identifier of
typedef struct
{
float alt;
float epe;
float eph;
float epv;
int fix;
double gps_tow;
double lat;
double lon;
float lon_vel;
float lat_vel;
float alt_vel;
float msl_hght;
int leap_sec;
long grmn_days;
} cpo_pvt_data;
alt Ellipsoid altitude (meters)
epe Estimated position error (meters)
eph Position error, horizontal (meters)
epv Position error, vertical (meters)
fix 0 = no fix; 1 = no fix; 2 = 2D; 3 = 3D; 4 = 2D differential; 5 = 3D differential;
6 and greater = not defined
gps_tow GPS time of week (sec)
lat Latitude (radians)
lon Longitude (radians)
lon_vel Longitude velocity (meters/second)
lat_vel Latitude velocity (meters/second)
alt_vel Altitude velocity (meters/second)
msl_hght Height (mean sea level) (meters)
leap_sec UTC leap seconds
grmn_days Garmin days (days since December 31, 1989)
DLE and ETX bytes:
Sample C code to receive the two records should filter DLE and ETX bytes as described below:
typedef enum
{
DAT,
DLE,
ETX
} rx_state_type;
/* Declare and initialize static variables */
static char
static int
static rx_state_type rx_state = DAT;
.
.
.
void add_to_que( char data )
{
(2's complement of the arithmetic sum of the bytes between the delimiters)
(DLE)
(ETX is last byte)
in_que[ 256 ];
in_que_ptr = 0;
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