ardupilot/libraries/SITL/SIM_GPS_NOVA.cpp

178 lines
4.0 KiB
C++

#include "SIM_config.h"
#if AP_SIM_GPS_NOVA_ENABLED
#include "SIM_GPS_NOVA.h"
#include <SITL/SITL.h>
using namespace SITL;
void GPS_NOVA::publish(const GPS_Data *d)
{
static struct PACKED nova_header
{
// 0
uint8_t preamble[3];
// 3
uint8_t headerlength;
// 4
uint16_t messageid;
// 6
uint8_t messagetype;
//7
uint8_t portaddr;
//8
uint16_t messagelength;
//10
uint16_t sequence;
//12
uint8_t idletime;
//13
uint8_t timestatus;
//14
uint16_t week;
//16
uint32_t tow;
//20
uint32_t recvstatus;
// 24
uint16_t resv;
//26
uint16_t recvswver;
} header;
struct PACKED psrdop
{
float gdop;
float pdop;
float hdop;
float htdop;
float tdop;
float cutoff;
uint32_t svcount;
// extra data for individual prns
} psrdop {};
struct PACKED bestpos
{
uint32_t solstat;
uint32_t postype;
double lat;
double lng;
double hgt;
float undulation;
uint32_t datumid;
float latsdev;
float lngsdev;
float hgtsdev;
// 4 bytes
uint8_t stnid[4];
float diffage;
float sol_age;
uint8_t svstracked;
uint8_t svsused;
uint8_t svsl1;
uint8_t svsmultfreq;
uint8_t resv;
uint8_t extsolstat;
uint8_t galbeisigmask;
uint8_t gpsglosigmask;
} bestpos {};
struct PACKED bestvel
{
uint32_t solstat;
uint32_t veltype;
float latency;
float age;
double horspd;
double trkgnd;
// + up
double vertspd;
float resv;
} bestvel {};
const auto gps_tow = gps_time();
header.preamble[0] = 0xaa;
header.preamble[1] = 0x44;
header.preamble[2] = 0x12;
header.headerlength = sizeof(header);
header.week = gps_tow.week;
header.tow = gps_tow.ms;
header.messageid = 174;
header.messagelength = sizeof(psrdop);
header.sequence += 1;
psrdop.hdop = 1.20;
psrdop.htdop = 1.20;
nova_send_message((uint8_t*)&header,sizeof(header),(uint8_t*)&psrdop, sizeof(psrdop));
header.messageid = 99;
header.messagelength = sizeof(bestvel);
header.sequence += 1;
bestvel.horspd = norm(d->speedN, d->speedE);
bestvel.trkgnd = ToDeg(atan2f(d->speedE, d->speedN));
bestvel.vertspd = -d->speedD;
nova_send_message((uint8_t*)&header,sizeof(header),(uint8_t*)&bestvel, sizeof(bestvel));
header.messageid = 42;
header.messagelength = sizeof(bestpos);
header.sequence += 1;
bestpos.lat = d->latitude;
bestpos.lng = d->longitude;
bestpos.hgt = d->altitude;
bestpos.svsused = d->have_lock ? _sitl->gps_numsats[instance] : 3;
bestpos.latsdev=0.2;
bestpos.lngsdev=0.2;
bestpos.hgtsdev=0.2;
bestpos.solstat=0;
bestpos.postype=32;
nova_send_message((uint8_t*)&header,sizeof(header),(uint8_t*)&bestpos, sizeof(bestpos));
}
void GPS_NOVA::nova_send_message(uint8_t *header, uint8_t headerlength, uint8_t *payload, uint8_t payloadlen)
{
write_to_autopilot((char*)header, headerlength);
write_to_autopilot((char*)payload, payloadlen);
uint32_t crc = CalculateBlockCRC32(headerlength, header, (uint32_t)0);
crc = CalculateBlockCRC32(payloadlen, payload, crc);
write_to_autopilot((char*)&crc, 4);
}
#define CRC32_POLYNOMIAL 0xEDB88320L
uint32_t GPS_NOVA::CRC32Value(uint32_t icrc)
{
int i;
uint32_t crc = icrc;
for ( i = 8 ; i > 0; i-- )
{
if ( crc & 1 )
crc = ( crc >> 1 ) ^ CRC32_POLYNOMIAL;
else
crc >>= 1;
}
return crc;
}
uint32_t GPS_NOVA::CalculateBlockCRC32(uint32_t length, uint8_t *buffer, uint32_t crc)
{
while ( length-- != 0 )
{
crc = ((crc >> 8) & 0x00FFFFFFL) ^ (CRC32Value(((uint32_t) crc ^ *buffer++) & 0xff));
}
return( crc );
}
#endif // AP_SIM_GPS_NOVA_ENABLED