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/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
// Novatel/Tersus/ComNav GPS driver for ArduPilot.
// Code by Michael Oborne
// Derived from http://www.novatel.com/assets/Documents/Manuals/om-20000129.pdf
#include "AP_GPS.h"
#include "AP_GPS_NOVA.h"
#include <AP_Logger/AP_Logger.h>
extern const AP_HAL::HAL& hal;
#define NOVA_DEBUGGING 0
#if NOVA_DEBUGGING
#include <cstdio>
# define Debug(fmt, args ...) \
do { \
printf("%s:%d: " fmt "\n", \
__FUNCTION__, __LINE__, \
## args); \
hal.scheduler->delay(1); \
} while(0)
#else
# define Debug(fmt, args ...)
#endif
AP_GPS_NOVA::AP_GPS_NOVA(AP_GPS &_gps, AP_GPS::GPS_State &_state,
AP_HAL::UARTDriver *_port) :
AP_GPS_Backend(_gps, _state, _port)
{
nova_msg.nova_state = nova_msg_parser::PREAMBLE1;
const char *init_str = _initialisation_blob[0];
const char *init_str1 = _initialisation_blob[1];
port->write((const uint8_t*)init_str, strlen(init_str));
port->write((const uint8_t*)init_str1, strlen(init_str1));
}
// Process all bytes available from the stream
//
bool
AP_GPS_NOVA::read(void)
{
uint32_t now = AP_HAL::millis();
if (_init_blob_index < (sizeof(_initialisation_blob) / sizeof(_initialisation_blob[0]))) {
const char *init_str = _initialisation_blob[_init_blob_index];
if (now > _init_blob_time) {
port->write((const uint8_t*)init_str, strlen(init_str));
_init_blob_time = now + 200;
_init_blob_index++;
}
}
bool ret = false;
while (port->available() > 0) {
uint8_t temp = port->read();
ret |= parse(temp);
}
return ret;
}
bool
AP_GPS_NOVA::parse(uint8_t temp)
{
switch (nova_msg.nova_state)
{
default:
case nova_msg_parser::PREAMBLE1:
if (temp == NOVA_PREAMBLE1)
nova_msg.nova_state = nova_msg_parser::PREAMBLE2;
nova_msg.read = 0;
break;
case nova_msg_parser::PREAMBLE2:
if (temp == NOVA_PREAMBLE2)
{
nova_msg.nova_state = nova_msg_parser::PREAMBLE3;
}
else
{
nova_msg.nova_state = nova_msg_parser::PREAMBLE1;
}
break;
case nova_msg_parser::PREAMBLE3:
if (temp == NOVA_PREAMBLE3)
{
nova_msg.nova_state = nova_msg_parser::HEADERLENGTH;
}
else
{
nova_msg.nova_state = nova_msg_parser::PREAMBLE1;
}
break;
case nova_msg_parser::HEADERLENGTH:
Debug("NOVA HEADERLENGTH\n");
nova_msg.header.data[0] = NOVA_PREAMBLE1;
nova_msg.header.data[1] = NOVA_PREAMBLE2;
nova_msg.header.data[2] = NOVA_PREAMBLE3;
nova_msg.header.data[3] = temp;
nova_msg.header.nova_headeru.headerlength = temp;
nova_msg.nova_state = nova_msg_parser::HEADERDATA;
nova_msg.read = 4;
break;
case nova_msg_parser::HEADERDATA:
if (nova_msg.read >= sizeof(nova_msg.header.data)) {
Debug("parse header overflow length=%u\n", (unsigned)nova_msg.read);
nova_msg.nova_state = nova_msg_parser::PREAMBLE1;
break;
}
nova_msg.header.data[nova_msg.read] = temp;
nova_msg.read++;
if (nova_msg.read >= nova_msg.header.nova_headeru.headerlength)
{
nova_msg.nova_state = nova_msg_parser::DATA;
}
break;
case nova_msg_parser::DATA:
if (nova_msg.read >= sizeof(nova_msg.data)) {
Debug("parse data overflow length=%u msglength=%u\n", (unsigned)nova_msg.read,nova_msg.header.nova_headeru.messagelength);
nova_msg.nova_state = nova_msg_parser::PREAMBLE1;
break;
}
nova_msg.data.bytes[nova_msg.read - nova_msg.header.nova_headeru.headerlength] = temp;
nova_msg.read++;
if (nova_msg.read >= (nova_msg.header.nova_headeru.messagelength + nova_msg.header.nova_headeru.headerlength))
{
Debug("NOVA DATA exit\n");
nova_msg.nova_state = nova_msg_parser::CRC1;
}
break;
case nova_msg_parser::CRC1:
nova_msg.crc = (uint32_t) (temp << 0);
nova_msg.nova_state = nova_msg_parser::CRC2;
break;
case nova_msg_parser::CRC2:
nova_msg.crc += (uint32_t) (temp << 8);
nova_msg.nova_state = nova_msg_parser::CRC3;
break;
case nova_msg_parser::CRC3:
nova_msg.crc += (uint32_t) (temp << 16);
nova_msg.nova_state = nova_msg_parser::CRC4;
break;
case nova_msg_parser::CRC4:
nova_msg.crc += (uint32_t) (temp << 24);
nova_msg.nova_state = nova_msg_parser::PREAMBLE1;
uint32_t crc = CalculateBlockCRC32((uint32_t)nova_msg.header.nova_headeru.headerlength, (uint8_t *)&nova_msg.header.data, (uint32_t)0);
crc = CalculateBlockCRC32((uint32_t)nova_msg.header.nova_headeru.messagelength, (uint8_t *)&nova_msg.data, crc);
if (nova_msg.crc == crc)
{
return process_message();
}
else
{
Debug("crc failed");
crc_error_counter++;
}
break;
}
return false;
}
bool
AP_GPS_NOVA::process_message(void)
{
uint16_t messageid = nova_msg.header.nova_headeru.messageid;
Debug("NOVA process_message messid=%u\n",messageid);
check_new_itow(nova_msg.header.nova_headeru.tow, nova_msg.header.nova_headeru.messagelength + nova_msg.header.nova_headeru.headerlength);
if (messageid == 42) // bestpos
{
const bestpos &bestposu = nova_msg.data.bestposu;
state.time_week = nova_msg.header.nova_headeru.week;
state.time_week_ms = (uint32_t) nova_msg.header.nova_headeru.tow;
state.last_gps_time_ms = AP_HAL::millis();
state.location.lat = (int32_t) (bestposu.lat * (double)1e7);
state.location.lng = (int32_t) (bestposu.lng * (double)1e7);
state.location.alt = (int32_t) (bestposu.hgt * 100);
state.num_sats = bestposu.svsused;
state.horizontal_accuracy = (float) ((bestposu.latsdev + bestposu.lngsdev)/2);
state.vertical_accuracy = (float) bestposu.hgtsdev;
state.have_horizontal_accuracy = true;
state.have_vertical_accuracy = true;
state.rtk_age_ms = bestposu.diffage * 1000;
state.rtk_num_sats = bestposu.svsused;
if (bestposu.solstat == 0) // have a solution
{
switch (bestposu.postype)
{
case 16:
state.status = AP_GPS::GPS_OK_FIX_3D;
break;
case 17: // psrdiff
case 18: // waas
case 20: // omnistar
case 68: // ppp_converg
case 69: // ppp
state.status = AP_GPS::GPS_OK_FIX_3D_DGPS;
break;
case 32: // l1 float
case 33: // iono float
case 34: // narrow float
state.status = AP_GPS::GPS_OK_FIX_3D_RTK_FLOAT;
break;
case 48: // l1 int
case 50: // narrow int
state.status = AP_GPS::GPS_OK_FIX_3D_RTK_FIXED;
break;
case 0: // NONE
case 1: // FIXEDPOS
case 2: // FIXEDHEIGHT
default:
state.status = AP_GPS::NO_FIX;
break;
}
}
else
{
state.status = AP_GPS::NO_FIX;
}
_new_position = true;
}
if (messageid == 99) // bestvel
{
const bestvel &bestvelu = nova_msg.data.bestvelu;
state.ground_speed = (float) bestvelu.horspd;
state.ground_course = (float) bestvelu.trkgnd;
fill_3d_velocity();
state.velocity.z = -(float) bestvelu.vertspd;
state.have_vertical_velocity = true;
_last_vel_time = (uint32_t) nova_msg.header.nova_headeru.tow;
_new_speed = true;
}
if (messageid == 174) // psrdop
{
const psrdop &psrdopu = nova_msg.data.psrdopu;
state.hdop = (uint16_t) (psrdopu.hdop*100);
state.vdop = (uint16_t) (psrdopu.htdop*100);
return false;
}
// ensure out position and velocity stay insync
if (_new_position && _new_speed && _last_vel_time == state.time_week_ms) {
_new_speed = _new_position = false;
return true;
}
return false;
}
void
AP_GPS_NOVA::inject_data(const uint8_t *data, uint16_t len)
{
if (port->txspace() > len) {
last_injected_data_ms = AP_HAL::millis();
port->write(data, len);
} else {
Debug("NOVA: Not enough TXSPACE");
}
}
#define CRC32_POLYNOMIAL 0xEDB88320L
uint32_t AP_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 AP_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 );
}
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