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AP_GPS_NMEA.cpp
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AP_GPS_NMEA.cpp
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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/>.
*/
//
// NMEA parser, adapted by Michael Smith from TinyGPS v9:
//
// TinyGPS - a small GPS library for Arduino providing basic NMEA parsing
// Copyright (C) 2008-9 Mikal Hart
// All rights reserved.
//
/// @file AP_GPS_NMEA.cpp
/// @brief NMEA protocol parser
///
/// This is a lightweight NMEA parser, derived originally from the
/// TinyGPS parser by Mikal Hart.
///
#include <AP_Common/AP_Common.h>
#include <AP_Common/NMEA.h>
#include <GCS_MAVLink/GCS.h>
#include <AP_Logger/AP_Logger.h>
#include <ctype.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include "AP_GPS_NMEA.h"
#if AP_GPS_NMEA_ENABLED
extern const AP_HAL::HAL& hal;
#ifndef AP_GPS_NMEA_CONFIG_PERIOD_MS
// how often we send board specific config commands
#define AP_GPS_NMEA_CONFIG_PERIOD_MS 15000U
#endif
// a quiet nan for invalid values
#define QNAN nanf("GPS")
// Convenience macros //////////////////////////////////////////////////////////
//
#define DIGIT_TO_VAL(_x) (_x - '0')
#define hexdigit(x) ((x)>9?'A'+((x)-10):'0'+(x))
bool AP_GPS_NMEA::read(void)
{
int16_t numc;
bool parsed = false;
send_config();
numc = port->available();
while (numc--) {
char c = port->read();
#if AP_GPS_DEBUG_LOGGING_ENABLED
log_data((const uint8_t *)&c, 1);
#endif
if (_decode(c)) {
parsed = true;
}
}
return parsed;
}
/*
decode one character, return true if we have successfully completed a sentence, false otherwise
*/
bool AP_GPS_NMEA::_decode(char c)
{
_sentence_length++;
switch (c) {
case ';':
// header separator for unicore
if (!_is_unicore) {
return false;
}
FALLTHROUGH;
case ',': // term terminators
_parity ^= c;
if (_is_unicore) {
_crc32 = crc_crc32(_crc32, (const uint8_t *)&c, 1);
}
FALLTHROUGH;
case '\r':
case '\n':
case '*': {
if (_sentence_done) {
return false;
}
bool valid_sentence = false;
if (_term_offset < sizeof(_term)) {
_term[_term_offset] = 0;
valid_sentence = _term_complete();
}
++_term_number;
_term_offset = 0;
_is_checksum_term = c == '*';
return valid_sentence;
}
case '$': // sentence begin
case '#': // unicore message begin
_is_unicore = (c == '#');
_term_number = _term_offset = 0;
_parity = 0;
_crc32 = 0;
_sentence_type = _GPS_SENTENCE_OTHER;
_is_checksum_term = false;
_sentence_length = 1;
_sentence_done = false;
_new_gps_yaw = QNAN;
return false;
}
// ordinary characters
if (_term_offset < sizeof(_term) - 1)
_term[_term_offset++] = c;
if (!_is_checksum_term) {
_parity ^= c;
if (_is_unicore) {
_crc32 = crc_crc32(_crc32, (const uint8_t *)&c, 1);
}
}
return false;
}
int32_t AP_GPS_NMEA::_parse_decimal_100(const char *p)
{
char *endptr = nullptr;
long ret = 100 * strtol(p, &endptr, 10);
int sign = ret < 0 ? -1 : 1;
if (ret >= (long)INT32_MAX) {
return INT32_MAX;
}
if (ret <= (long)INT32_MIN) {
return INT32_MIN;
}
if (endptr == nullptr || *endptr != '.') {
return ret;
}
if (isdigit(endptr[1])) {
ret += sign * 10 * DIGIT_TO_VAL(endptr[1]);
if (isdigit(endptr[2])) {
ret += sign * DIGIT_TO_VAL(endptr[2]);
if (isdigit(endptr[3])) {
ret += sign * (DIGIT_TO_VAL(endptr[3]) >= 5);
}
}
}
return ret;
}
/*
parse a NMEA latitude/longitude degree value. The result is in degrees*1e7
*/
uint32_t AP_GPS_NMEA::_parse_degrees()
{
char *p, *q;
uint8_t deg = 0, min = 0;
float frac_min = 0;
int32_t ret = 0;
// scan for decimal point or end of field
for (p = _term; *p && isdigit(*p); p++)
;
q = _term;
// convert degrees
while ((p - q) > 2 && *q) {
if (deg)
deg *= 10;
deg += DIGIT_TO_VAL(*q++);
}
// convert minutes
while (p > q && *q) {
if (min)
min *= 10;
min += DIGIT_TO_VAL(*q++);
}
// convert fractional minutes
if (*p == '.') {
q = p + 1;
float frac_scale = 0.1f;
while (*q && isdigit(*q)) {
frac_min += DIGIT_TO_VAL(*q) * frac_scale;
q++;
frac_scale *= 0.1f;
}
}
ret = (deg * (int32_t)10000000UL);
ret += (min * (int32_t)10000000UL / 60);
ret += (int32_t) (frac_min * (1.0e7f / 60.0f));
return ret;
}
/*
see if we have a new set of NMEA messages
*/
bool AP_GPS_NMEA::_have_new_message()
{
if (_last_RMC_ms == 0 ||
_last_GGA_ms == 0) {
return false;
}
uint32_t now = AP_HAL::millis();
if (now - _last_RMC_ms > 150 ||
now - _last_GGA_ms > 150) {
return false;
}
if (_last_VTG_ms != 0 &&
now - _last_VTG_ms > 150) {
return false;
}
/*
if we have seen a message with 3D velocity data messages then
wait for them again. This is important as the
have_vertical_velocity field will be overwritten by
fill_3d_velocity()
*/
if (_last_vvelocity_ms != 0 &&
now - _last_vvelocity_ms > 150 &&
now - _last_vvelocity_ms < 1000) {
// waiting on a message with velocity
return false;
}
if (_last_vaccuracy_ms != 0 &&
now - _last_vaccuracy_ms > 150 &&
now - _last_vaccuracy_ms < 1000) {
// waiting on a message with velocity accuracy
return false;
}
// prevent these messages being used again
if (_last_VTG_ms != 0) {
_last_VTG_ms = 1;
}
if (now - _last_yaw_ms > 300) {
// we have lost GPS yaw
state.have_gps_yaw = false;
}
if (now - _last_KSXT_pos_ms > 500) {
// we have lost KSXT
_last_KSXT_pos_ms = 0;
}
#if AP_GPS_NMEA_UNICORE_ENABLED
if (now - _last_AGRICA_ms > 500) {
if (_last_AGRICA_ms != 0) {
// we have lost AGRICA
state.have_gps_yaw = false;
state.have_vertical_velocity = false;
state.have_speed_accuracy = false;
state.have_horizontal_accuracy = false;
state.have_vertical_accuracy = false;
state.have_undulation = false;
_last_AGRICA_ms = 0;
}
}
#endif // AP_GPS_NMEA_UNICORE_ENABLED
_last_fix_ms = now;
_last_GGA_ms = 1;
_last_RMC_ms = 1;
return true;
}
// Processes a just-completed term
// Returns true if new sentence has just passed checksum test and is validated
bool AP_GPS_NMEA::_term_complete()
{
// handle the last term in a message
if (_is_checksum_term) {
_sentence_done = true;
const uint32_t crc = strtoul(_term, nullptr, 16);
const bool crc_ok = _is_unicore? (_crc32 == crc) : (_parity == crc);
if (crc_ok) {
uint32_t now = AP_HAL::millis();
switch (_sentence_type) {
case _GPS_SENTENCE_RMC:
_last_RMC_ms = now;
//time = _new_time;
//date = _new_date;
if (_last_KSXT_pos_ms == 0 && _last_AGRICA_ms == 0) {
state.location.lat = _new_latitude;
state.location.lng = _new_longitude;
}
if (_last_3D_velocity_ms == 0 ||
now - _last_3D_velocity_ms > 1000) {
state.ground_speed = _new_speed*0.01f;
state.ground_course = wrap_360(_new_course*0.01f);
}
if (state.status >= AP_GPS::GPS_OK_FIX_3D) {
make_gps_time(_new_date, _new_time * 10);
if (_last_AGRICA_ms != 0) {
state.time_week_ms = _last_itow_ms;
}
}
set_uart_timestamp(_sentence_length);
state.last_gps_time_ms = now;
if (_last_vvelocity_ms == 0 ||
now - _last_vvelocity_ms > 1000) {
fill_3d_velocity();
}
break;
case _GPS_SENTENCE_GGA:
_last_GGA_ms = now;
if (_last_KSXT_pos_ms == 0 && _last_AGRICA_ms == 0) {
set_alt_amsl_cm(state, _new_altitude);
state.location.lat = _new_latitude;
state.location.lng = _new_longitude;
}
state.num_sats = _new_satellite_count;
state.hdop = _new_hdop;
switch(_new_quality_indicator) {
case 0: // Fix not available or invalid
state.status = AP_GPS::NO_FIX;
break;
case 1: // GPS SPS Mode, fix valid
state.status = AP_GPS::GPS_OK_FIX_3D;
break;
case 2: // Differential GPS, SPS Mode, fix valid
state.status = AP_GPS::GPS_OK_FIX_3D_DGPS;
break;
case 3: // GPS PPS Mode, fix valid
state.status = AP_GPS::GPS_OK_FIX_3D;
break;
case 4: // Real Time Kinematic. System used in RTK mode with fixed integers
state.status = AP_GPS::GPS_OK_FIX_3D_RTK_FIXED;
break;
case 5: // Float RTK. Satellite system used in RTK mode, floating integers
state.status = AP_GPS::GPS_OK_FIX_3D_RTK_FLOAT;
break;
case 6: // Estimated (dead reckoning) Mode
state.status = AP_GPS::NO_FIX;
break;
default://to maintain compatibility with MAV_GPS_INPUT and others
state.status = AP_GPS::GPS_OK_FIX_3D;
break;
}
break;
case _GPS_SENTENCE_VTG:
_last_VTG_ms = now;
if (_last_3D_velocity_ms == 0 ||
now - _last_3D_velocity_ms > 1000) {
state.ground_speed = _new_speed*0.01f;
state.ground_course = wrap_360(_new_course*0.01f);
if (_last_vvelocity_ms == 0 ||
now - _last_vvelocity_ms > 1000) {
fill_3d_velocity();
}
}
// VTG has no fix indicator, can't change fix status
break;
case _GPS_SENTENCE_HDT:
case _GPS_SENTENCE_THS:
if (_last_AGRICA_ms != 0 || _expect_agrica) {
// use AGRICA
break;
}
if (isnan(_new_gps_yaw)) {
// empty sentence
break;
}
_last_yaw_ms = now;
state.gps_yaw = wrap_360(_new_gps_yaw*0.01f);
state.have_gps_yaw = true;
state.gps_yaw_time_ms = now;
// remember that we are setup to provide yaw. With
// a NMEA GPS we can only tell if the GPS is
// configured to provide yaw when it first sends a
// HDT sentence.
state.gps_yaw_configured = true;
break;
case _GPS_SENTENCE_PHD:
if (_last_AGRICA_ms != 0) {
// prefer AGRICA
break;
}
if (_phd.msg_id == 12) {
state.velocity.x = _phd.fields[0] * 0.01;
state.velocity.y = _phd.fields[1] * 0.01;
state.velocity.z = _phd.fields[2] * 0.01;
state.have_vertical_velocity = true;
_last_vvelocity_ms = now;
// we prefer a true 3D velocity when available
velocity_to_speed_course(state);
_last_3D_velocity_ms = now;
} else if (_phd.msg_id == 26) {
state.horizontal_accuracy = MAX(_phd.fields[0],_phd.fields[1]) * 0.001;
state.have_horizontal_accuracy = true;
state.vertical_accuracy = _phd.fields[2] * 0.001;
state.have_vertical_accuracy = true;
state.speed_accuracy = MAX(_phd.fields[3],_phd.fields[4]) * 0.001;
state.have_speed_accuracy = true;
_last_vaccuracy_ms = now;
}
break;
case _GPS_SENTENCE_KSXT:
if (_last_AGRICA_ms != 0 || _expect_agrica) {
// prefer AGRICA
break;
}
state.location.lat = _ksxt.fields[2]*1.0e7;
state.location.lng = _ksxt.fields[1]*1.0e7;
set_alt_amsl_cm(state, _ksxt.fields[3]*1.0e2);
_last_KSXT_pos_ms = now;
if (_ksxt.fields[9] >= 1) {
// we have 3D fix
constexpr float kmh_to_mps = 1.0 / 3.6;
state.velocity.y = _ksxt.fields[16] * kmh_to_mps;
state.velocity.x = _ksxt.fields[17] * kmh_to_mps;
state.velocity.z = _ksxt.fields[18] * -kmh_to_mps;
state.have_vertical_velocity = true;
_last_vvelocity_ms = now;
// we prefer a true 3D velocity when available
velocity_to_speed_course(state);
_last_3D_velocity_ms = now;
}
if (is_equal(3.0f, float(_ksxt.fields[10]))) {
// have good yaw (from RTK fixed moving baseline solution)
_last_yaw_ms = now;
state.gps_yaw = _ksxt.fields[4];
state.have_gps_yaw = true;
state.gps_yaw_time_ms = now;
state.gps_yaw_configured = true;
}
break;
#if AP_GPS_NMEA_UNICORE_ENABLED
case _GPS_SENTENCE_AGRICA: {
const auto &ag = _agrica;
_last_AGRICA_ms = now;
_last_vvelocity_ms = now;
_last_vaccuracy_ms = now;
_last_3D_velocity_ms = now;
state.location.lat = ag.lat*1.0e7;
state.location.lng = ag.lng*1.0e7;
state.undulation = -ag.undulation;
state.have_undulation = true;
set_alt_amsl_cm(state, ag.alt*1.0e2);
state.velocity = ag.vel_NED;
velocity_to_speed_course(state);
state.speed_accuracy = ag.vel_stddev.length();
state.horizontal_accuracy = ag.pos_stddev.xy().length();
state.vertical_accuracy = ag.pos_stddev.z;
state.have_vertical_velocity = true;
state.have_speed_accuracy = true;
state.have_horizontal_accuracy = true;
state.have_vertical_accuracy = true;
check_new_itow(ag.itow, _sentence_length);
break;
}
case _GPS_SENTENCE_VERSIONA: {
_have_unicore_versiona = true;
GCS_SEND_TEXT(MAV_SEVERITY_INFO,
"NMEA %s %s %s",
_versiona.type,
_versiona.version,
_versiona.build_date);
break;
}
case _GPS_SENTENCE_UNIHEADINGA: {
#if GPS_MOVING_BASELINE
const auto &ag = _agrica;
const auto &uh = _uniheadinga;
if (now - _last_AGRICA_ms > 500 || ag.heading_status != 4) {
// we need heading_status from AGRICA
state.have_gps_yaw = false;
break;
}
const float dist = uh.baseline_length;
const float bearing = uh.heading;
const float alt_diff = dist*tanf(radians(-uh.pitch));
state.relPosHeading = bearing;
state.relPosLength = dist;
state.relPosD = alt_diff;
state.relposheading_ts = now;
if (calculate_moving_base_yaw(bearing, dist, alt_diff)) {
state.have_gps_yaw_accuracy = true;
state.gps_yaw_accuracy = uh.heading_sd;
_last_yaw_ms = now;
}
state.gps_yaw_configured = true;
#endif // GPS_MOVING_BASELINE
break;
}
#endif // AP_GPS_NMEA_UNICORE_ENABLED
}
// see if we got a good message
return _have_new_message();
}
// we got a bad message, ignore it
return false;
}
// the first term determines the sentence type
if (_term_number == 0) {
/*
special case for $PHD message
*/
if (strcmp(_term, "PHD") == 0) {
_sentence_type = _GPS_SENTENCE_PHD;
return false;
}
if (strcmp(_term, "KSXT") == 0) {
_sentence_type = _GPS_SENTENCE_KSXT;
return false;
}
#if AP_GPS_NMEA_UNICORE_ENABLED
if (strcmp(_term, "AGRICA") == 0 && _expect_agrica) {
_sentence_type = _GPS_SENTENCE_AGRICA;
return false;
}
if (strcmp(_term, "VERSIONA") == 0) {
_sentence_type = _GPS_SENTENCE_VERSIONA;
return false;
}
if (strcmp(_term, "UNIHEADINGA") == 0 && _expect_agrica) {
_sentence_type = _GPS_SENTENCE_UNIHEADINGA;
return false;
}
#endif
/*
The first two letters of the NMEA term are the talker
ID. The most common is 'GP' but there are a bunch of others
that are valid. We accept any two characters here.
*/
if (_term[0] < 'A' || _term[0] > 'Z' ||
_term[1] < 'A' || _term[1] > 'Z') {
_sentence_type = _GPS_SENTENCE_OTHER;
return false;
}
const char *term_type = &_term[2];
if (strcmp(term_type, "RMC") == 0) {
_sentence_type = _GPS_SENTENCE_RMC;
} else if (strcmp(term_type, "GGA") == 0) {
_sentence_type = _GPS_SENTENCE_GGA;
} else if (strcmp(term_type, "HDT") == 0) {
_sentence_type = _GPS_SENTENCE_HDT;
} else if (strcmp(term_type, "THS") == 0) {
_sentence_type = _GPS_SENTENCE_THS;
} else if (strcmp(term_type, "VTG") == 0) {
_sentence_type = _GPS_SENTENCE_VTG;
} else {
_sentence_type = _GPS_SENTENCE_OTHER;
}
return false;
}
// 32 = RMC, 64 = GGA, 96 = VTG, 128 = HDT, 160 = THS
if (_sentence_type != _GPS_SENTENCE_OTHER && _term[0]) {
switch (_sentence_type + _term_number) {
// operational status
//
case _GPS_SENTENCE_RMC + 2: // validity (RMC)
break;
case _GPS_SENTENCE_GGA + 6: // Fix data (GGA)
if (_term[0] > '0') {
_new_quality_indicator = _term[0] - '0';
} else {
_new_quality_indicator = 0;
}
break;
case _GPS_SENTENCE_GGA + 7: // satellite count (GGA)
_new_satellite_count = atol(_term);
break;
case _GPS_SENTENCE_GGA + 8: // HDOP (GGA)
_new_hdop = (uint16_t)_parse_decimal_100(_term);
break;
// time and date
//
case _GPS_SENTENCE_RMC + 1: // Time (RMC)
case _GPS_SENTENCE_GGA + 1: // Time (GGA)
_new_time = _parse_decimal_100(_term);
break;
case _GPS_SENTENCE_RMC + 9: // Date (GPRMC)
_new_date = atol(_term);
break;
// location
//
case _GPS_SENTENCE_RMC + 3: // Latitude
case _GPS_SENTENCE_GGA + 2:
_new_latitude = _parse_degrees();
break;
case _GPS_SENTENCE_RMC + 4: // N/S
case _GPS_SENTENCE_GGA + 3:
if (_term[0] == 'S')
_new_latitude = -_new_latitude;
break;
case _GPS_SENTENCE_RMC + 5: // Longitude
case _GPS_SENTENCE_GGA + 4:
_new_longitude = _parse_degrees();
break;
case _GPS_SENTENCE_RMC + 6: // E/W
case _GPS_SENTENCE_GGA + 5:
if (_term[0] == 'W')
_new_longitude = -_new_longitude;
break;
case _GPS_SENTENCE_GGA + 9: // Altitude (GPGGA)
_new_altitude = _parse_decimal_100(_term);
break;
// course and speed
//
case _GPS_SENTENCE_RMC + 7: // Speed (GPRMC)
case _GPS_SENTENCE_VTG + 5: // Speed (VTG)
_new_speed = (_parse_decimal_100(_term) * 514) / 1000; // knots-> m/sec, approximates * 0.514
break;
case _GPS_SENTENCE_HDT + 1: // Course (HDT)
_new_gps_yaw = _parse_decimal_100(_term);
break;
case _GPS_SENTENCE_THS + 1: // Course (THS)
_new_gps_yaw = _parse_decimal_100(_term);
break;
case _GPS_SENTENCE_RMC + 8: // Course (GPRMC)
case _GPS_SENTENCE_VTG + 1: // Course (VTG)
_new_course = _parse_decimal_100(_term);
break;
case _GPS_SENTENCE_PHD + 1: // PHD class
_phd.msg_class = atol(_term);
break;
case _GPS_SENTENCE_PHD + 2: // PHD message
_phd.msg_id = atol(_term);
break;
case _GPS_SENTENCE_PHD + 5: // PHD message, itow
_phd.itow = strtoul(_term, nullptr, 10);
break;
case _GPS_SENTENCE_PHD + 6 ... _GPS_SENTENCE_PHD + 11: // PHD message, fields
_phd.fields[_term_number-6] = atol(_term);
break;
case _GPS_SENTENCE_KSXT + 1 ... _GPS_SENTENCE_KSXT + 22: // KSXT message, fields
_ksxt.fields[_term_number-1] = atof(_term);
break;
#if AP_GPS_NMEA_UNICORE_ENABLED
case _GPS_SENTENCE_AGRICA + 1 ... _GPS_SENTENCE_AGRICA + 65: // AGRICA message
parse_agrica_field(_term_number, _term);
break;
case _GPS_SENTENCE_VERSIONA + 1 ... _GPS_SENTENCE_VERSIONA + 20:
parse_versiona_field(_term_number, _term);
break;
#if GPS_MOVING_BASELINE
case _GPS_SENTENCE_UNIHEADINGA + 1 ... _GPS_SENTENCE_UNIHEADINGA + 28: // UNIHEADINGA message
parse_uniheadinga_field(_term_number, _term);
break;
#endif
#endif
}
}
return false;
}
#if AP_GPS_NMEA_UNICORE_ENABLED
/*
parse an AGRICA message term
Example:
#AGRICA,82,GPS,FINE,2237,176366400,0,0,18,15;GNSS,232,22,11,22,0,59,8,1,5,8,12,0,0.0000,0.0000,0.0000,0.0000,0.0000,0.0000,296.4656,-26.5685,0.0000,0.005,0.000,0.000,-0.005,0.044,0.032,0.038,-35.33142715815,149.13181842030,609.1494,-4471799.0368,2672944.7758,-3668288.9857,1.3923,1.5128,3.2272,2.3026,2.1633,2.1586,0.00000000000,0.00000000000,0.0000,0.00000000000,0.00000000000,0.0000,176366400,0.000,66.175285,18.972784,0.000000,0.000000,5,0,0,0*9f704dad
*/
void AP_GPS_NMEA::parse_agrica_field(uint16_t term_number, const char *term)
{
auto &ag = _agrica;
// subtract 8 to align term numbers with reference manual
// look for "Unicore Reference Command Manual" to find the specification
const uint8_t hdr_align = 8;
if (term_number < hdr_align) {
// discard header;
return;
}
term_number -= hdr_align;
// useful for debugging
//::printf("AGRICA[%u]=%s\n", unsigned(term_number), term);
switch (term_number) {
case 10:
ag.rtk_status = atol(term);
break;
case 11:
ag.heading_status = atol(term);
break;
case 25 ... 26:
ag.vel_NED[term_number-25] = atof(term);
break;
case 27:
// AGRIC gives velocity up
ag.vel_NED.z = -atof(term);
break;
case 28 ... 30:
ag.vel_stddev[term_number-28] = atof(term);
break;
case 31:
ag.lat = atof(term);
break;
case 32:
ag.lng = atof(term);
break;
case 33:
ag.alt = atof(term);
break;
case 49:
ag.itow = atol(term);
break;
case 37 ... 39:
ag.pos_stddev[term_number-37] = atof(term);
break;
case 52:
ag.undulation = atof(term);
break;
}
}
#if GPS_MOVING_BASELINE
/*
parse a UNIHEADINGA message term
Example:
#UNIHEADINGA,79,GPS,FINE,2242,167498200,0,0,18,22;SOL_COMPUTED,L1_INT,2.7889,296.7233,-25.7710,0.0000,0.1127,0.1812,"999",49,37,37,0,3,00,1,51*d50af0ea
*/
void AP_GPS_NMEA::parse_uniheadinga_field(uint16_t term_number, const char *term)
{
const uint8_t hdr_align = 8;
if (term_number < hdr_align) {
// discard header;
return;
}
term_number -= hdr_align;
// useful for debugging
// ::printf("UNIHEADINGA[%u]=%s\n", unsigned(term_number), term);
auto &uh = _uniheadinga;
switch (term_number) {
case 4:
uh.baseline_length = atof(term);
break;
case 5:
uh.heading = atof(term);
break;
case 6:
uh.pitch = atof(term);
break;
case 8:
uh.heading_sd = atof(term);
break;
}
}
#endif // GPS_MOVING_BASELINE
// parse VERSIONA fields
void AP_GPS_NMEA::parse_versiona_field(uint16_t term_number, const char *term)
{
// printf useful for debugging
// ::printf("VERSIONA[%u]='%s'\n", term_number, term);
auto &v = _versiona;
#pragma GCC diagnostic push
#if defined(__GNUC__) && __GNUC__ >= 9
#pragma GCC diagnostic ignored "-Wstringop-truncation"
#endif
switch (term_number) {
case 10:
strncpy(v.type, _term, sizeof(v.type)-1);
break;
case 11:
strncpy(v.version, _term, sizeof(v.version)-1);
break;
case 15:
strncpy(v.build_date, _term, sizeof(v.build_date)-1);
break;
}
#pragma GCC diagnostic pop
}
#endif // AP_GPS_NMEA_UNICORE_ENABLED
/*
detect a NMEA GPS. Adds one byte, and returns true if the stream
matches a NMEA string
*/
bool
AP_GPS_NMEA::_detect(struct NMEA_detect_state &state, uint8_t data)
{
switch (state.step) {
case 0:
state.ck = 0;
if ('$' == data) {
state.step++;
}
break;
case 1:
if ('*' == data) {
state.step++;
} else {
state.ck ^= data;
}
break;
case 2:
if (hexdigit(state.ck>>4) == data) {
state.step++;
} else {
state.step = 0;
}
break;
case 3:
if (hexdigit(state.ck&0xF) == data) {
state.step = 0;
return true;
}
state.step = 0;
break;
}
return false;
}
/*
send type specific config strings
*/
void AP_GPS_NMEA::send_config(void)
{
const auto type = get_type();
_expect_agrica = (type == AP_GPS::GPS_TYPE_UNICORE_NMEA ||
type == AP_GPS::GPS_TYPE_UNICORE_MOVINGBASE_NMEA);
if (gps._auto_config == AP_GPS::GPS_AUTO_CONFIG_DISABLE) {
// not doing auto-config
return;
}
uint32_t now_ms = AP_HAL::millis();
if (now_ms - last_config_ms < AP_GPS_NMEA_CONFIG_PERIOD_MS) {
return;
}
last_config_ms = now_ms;
const uint16_t rate_ms = params.rate_ms;
#if AP_GPS_NMEA_UNICORE_ENABLED
const float rate_s = rate_ms * 0.001;
#endif
const uint8_t rate_hz = 1000U / rate_ms;
switch (get_type()) {
#if AP_GPS_NMEA_UNICORE_ENABLED
case AP_GPS::GPS_TYPE_UNICORE_MOVINGBASE_NMEA:
port->printf("\r\nCONFIG HEADING FIXLENGTH\r\n" \
"CONFIG UNDULATION AUTO\r\n" \
"CONFIG\r\n" \
"UNIHEADINGA %.3f\r\n",
rate_s);
state.gps_yaw_configured = true;
FALLTHROUGH;
case AP_GPS::GPS_TYPE_UNICORE_NMEA: {
port->printf("\r\nAGRICA %.3f\r\n" \
"MODE MOVINGBASE\r\n" \
"GNGGA %.3f\r\n" \
"GNRMC %.3f\r\n",
rate_s, rate_s, rate_s);
if (!_have_unicore_versiona) {
// get version information for logging if we don't have it yet
port->printf("VERSIONA\r\n");
if (gps._save_config) {
// save config changes for fast startup
port->printf("SAVECONFIG\r\n");
}
}
break;
}
#endif // AP_GPS_NMEA_UNICORE_ENABLED
case AP_GPS::GPS_TYPE_HEMI: {
port->printf(
"$JATT,NMEAHE,0\r\n" /* Prefix of GP on the HDT message */ \
"$JASC,GPGGA,%u\r\n" /* GGA at 5Hz */ \
"$JASC,GPRMC,%u\r\n" /* RMC at 5Hz */ \
"$JASC,GPVTG,%u\r\n" /* VTG at 5Hz */ \
"$JASC,GPHDT,%u\r\n" /* HDT at 5Hz */ \
"$JMODE,SBASR,YES\r\n" /* Enable SBAS */,
rate_hz, rate_hz, rate_hz, rate_hz);
break;
}
case AP_GPS::GPS_TYPE_ALLYSTAR:
nmea_printf(port, "$PHD,06,42,UUUUTTTT,BB,0,%u,55,0,%u,0,0,0",
unsigned(rate_hz), unsigned(rate_ms));
break;
default:
break;
}
#ifdef AP_GPS_NMEA_CUSTOM_CONFIG_STRING
// allow for custom config strings, useful for peripherals
port->printf("%s\r\n", AP_GPS_NMEA_CUSTOM_CONFIG_STRING);
#endif
}
/*
return health status
*/
bool AP_GPS_NMEA::is_healthy(void) const
{
switch (get_type()) {
#if AP_GPS_NMEA_UNICORE_ENABLED
case AP_GPS::GPS_TYPE_UNICORE_MOVINGBASE_NMEA:
case AP_GPS::GPS_TYPE_UNICORE_NMEA:
// we should be getting AGRICA messages
return _last_AGRICA_ms != 0;
#endif // AP_GPS_NMEA_UNICORE_ENABLED
case AP_GPS::GPS_TYPE_HEMI:
// we should be getting HDR for yaw
return _last_yaw_ms != 0;
case AP_GPS::GPS_TYPE_ALLYSTAR:
// we should get vertical velocity and accuracy from PHD
return _last_vvelocity_ms != 0 && _last_vaccuracy_ms != 0;
default:
break;
}
return true;
}
// get the velocity lag
bool AP_GPS_NMEA::get_lag(float &lag_sec) const
{
switch (get_type()) {
#if AP_GPS_NMEA_UNICORE_ENABLED
case AP_GPS::GPS_TYPE_UNICORE_MOVINGBASE_NMEA:
case AP_GPS::GPS_TYPE_UNICORE_NMEA:
lag_sec = 0.14;
break;
#endif // AP_GPS_NMEA_UNICORE_ENABLED
default:
lag_sec = 0.2;
break;
}
return true;
}
#if HAL_LOGGING_ENABLED
void AP_GPS_NMEA::Write_AP_Logger_Log_Startup_messages() const
{
AP_GPS_Backend::Write_AP_Logger_Log_Startup_messages();
#if AP_GPS_NMEA_UNICORE_ENABLED
if (_have_unicore_versiona) {
AP::logger().Write_MessageF("NMEA %u %s %s %s",
state.instance+1,
_versiona.type,
_versiona.version,
_versiona.build_date);
}
#endif
}
#endif
#endif // AP_GPS_NMEA_ENABLED