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Revised nmea and Garmin protocol classes.

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The Garmin protocol implementation really is an NMEA protocol with a few
extra messages. Instead of duplicating the code, introduce the NMEA protocol
as a base class, which is reused for the Garmin class. The input/output
has not changed at all (and it maintains the FG-specific quirks, like our
NMEA class using LF-only linefeeds, while the Garmin protocol uses
CR-LF linefeeds.
This commit is contained in:
ThorstenB 2017-11-19 00:28:04 +01:00
parent 6ff4805361
commit ad866afd81
4 changed files with 396 additions and 845 deletions
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444
src/Network/garmin.cxx
View file

@ -1,4 +1,4 @@
// garmin.cxx -- Garmin protocal class
// garmin.cxx -- Garmin protocol class
//
// Written by Curtis Olson, started November 1999.
//
@ -24,414 +24,80 @@
# include "config.h"
#endif
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <simgear/debug/logstream.hxx>
#include <simgear/math/sg_geodesy.hxx>
#include <simgear/io/iochannel.hxx>
#include <simgear/timing/sg_time.hxx>
#include <FDM/flightProperties.hxx>
#include <Main/fg_props.hxx>
#include <Main/globals.hxx>
#include <simgear/constants.h>
#include "garmin.hxx"
using std::string;
using namespace NMEA;
FGGarmin::FGGarmin() {
fdm = new FlightProperties;
}
FGGarmin::~FGGarmin() {
delete fdm;
FGGarmin::FGGarmin() :
FGNMEA(),
mGarminMessages(GARMIN::PGRMZ),
mMetric(true) // use metric altitude reports
// In fact Garmin devices normally seem report barometric altitude in feet (not meters), but
// the FG implementation has always used metric reports for years (and we keep it this way,
// to avoid complaints about changed implementation). The unit is also part of the NMEA message,
// so smart devices are probably ok with both anyway.
{
// only enable the GPRMC standard NMEA message
mNmeaMessages = NMEA::GPRMC;
// Garmin uses CR-LF line feeds.
mLineFeed = "\r\n";
}
// calculate the garmin check sum
static char calc_nmea_cksum(char *sentence) {
unsigned char sum = 0;
int i, len;
len = strlen(sentence);
sum = sentence[0];
for ( i = 1; i < len; i++ ) {
sum ^= sentence[i];
}
return sum;
FGGarmin::~FGGarmin()
{
}
// generate Garmin message
bool FGGarmin::gen_message() {
char rmc[256], rmc_sum[256], rmz[256], rmz_sum[256], gsa[256];
char dir;
int deg;
double min;
// generate Garmin NMEA messages
bool FGGarmin::gen_message()
{
(void) FGNMEA::gen_message();
SGTime *t = globals->get_time_params();
char nmea[256];
char utc[10];
sprintf( utc, "%02d%02d%02d",
t->getGmt()->tm_hour, t->getGmt()->tm_min, t->getGmt()->tm_sec );
// RMZ sentence (Garmin proprietary)
if (mGarminMessages & GARMIN::PGRMZ)
{
double altitude_ft = mFdm.get_Altitude();
char rmc_lat[20];
double latd = fdm->get_Latitude() * SGD_RADIANS_TO_DEGREES;
if ( latd < 0.0 ) {
latd = -latd;
dir = 'S';
} else {
dir = 'N';
}
deg = (int)(latd);
min = (latd - (double)deg) * 60.0;
sprintf( rmc_lat, "%02d%07.4f,%c", abs(deg), min, dir);
char rmc_lon[20];
double lond = fdm->get_Longitude() * SGD_RADIANS_TO_DEGREES;
if ( lond < 0.0 ) {
lond = -lond;
dir = 'W';
} else {
dir = 'E';
}
deg = (int)(lond);
min = (lond - (double)deg) * 60.0;
sprintf( rmc_lon, "%03d%07.4f,%c", abs(deg), min, dir);
char speed[10];
sprintf( speed, "%05.1f", fdm->get_V_equiv_kts() );
char heading[10];
sprintf( heading, "%05.1f", fdm->get_Psi() * SGD_RADIANS_TO_DEGREES );
char altitude_m[10];
sprintf( altitude_m, "%02d",
(int)(fdm->get_Altitude() * SG_FEET_TO_METER) );
char date[10];
int year = t->getGmt()->tm_year;
while ( year >= 100 ) { year -= 100; }
sprintf( date, "%02d%02d%02d", t->getGmt()->tm_mday,
t->getGmt()->tm_mon+1, year );
char magvar[10];
float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
if ( magdeg < 0.0 ) {
magdeg = -magdeg;
dir = 'W';
} else {
dir = 'E';
}
sprintf( magvar, "%05.1f,%c", magdeg, dir );
// $GPRMC,HHMMSS,A,DDMM.MMMM,N,DDDMM.MMMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E*XX
sprintf( rmc, "GPRMC,%s,A,%s,%s,%s,%s,%s,%s",
utc, rmc_lat, rmc_lon, speed, heading, date, magvar );
sprintf( rmc_sum, "%02X", calc_nmea_cksum(rmc) );
// sprintf( gga, "$GPGGA,%s,%s,%s,1,04,0.0,%s,M,00.0,M,,*00\r\n",
// utc, lat, lon, altitude_m );
sprintf( rmz, "PGRMZ,%s,M,3", altitude_m );
sprintf( rmz_sum, "%02X", calc_nmea_cksum(rmz) );
sprintf( gsa, "%s",
"$GPGSA,A,3,01,02,03,,05,,07,,09,,11,12,0.9,0.9,2.0*38" );
SG_LOG( SG_IO, SG_DEBUG, rmc );
SG_LOG( SG_IO, SG_DEBUG, rmz );
SG_LOG( SG_IO, SG_DEBUG, gsa );
string garmin_sentence;
// RMC sentence
garmin_sentence = "$";
garmin_sentence += rmc;
garmin_sentence += "*";
garmin_sentence += rmc_sum;
garmin_sentence += "\r\n";
// RMZ sentence (garmin proprietary)
garmin_sentence += "$";
garmin_sentence += rmz;
garmin_sentence += "*";
garmin_sentence += rmz_sum;
garmin_sentence += "\r\n";
// GSA sentence (totally faked)
garmin_sentence += gsa;
garmin_sentence += "\r\n";
length = garmin_sentence.length();
strncpy( buf, garmin_sentence.c_str(), length );
return true;
}
// parse Garmin message
bool FGGarmin::parse_message() {
SG_LOG( SG_IO, SG_INFO, "parse garmin message" );
string msg = buf;
msg = msg.substr( 0, length );
SG_LOG( SG_IO, SG_INFO, "entire message = " << msg );
string::size_type begin_line, end_line, begin, end;
begin_line = begin = 0;
// extract out each line
end_line = msg.find("\n", begin_line);
while ( end_line != string::npos ) {
string line = msg.substr(begin_line, end_line - begin_line);
begin_line = end_line + 1;
SG_LOG( SG_IO, SG_INFO, " input line = " << line );
// leading character
string start = msg.substr(begin, 1);
++begin;
SG_LOG( SG_IO, SG_INFO, " start = " << start );
// sentence
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string sentence = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " sentence = " << sentence );
double lon_deg, lon_min, lat_deg, lat_min;
double lon, lat, speed, heading, altitude;
if ( sentence == "GPRMC" ) {
// time
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string utc = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
// junk
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string junk = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
// lat val
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lat_str = msg.substr(begin, end - begin);
begin = end + 1;
lat_deg = atof( lat_str.substr(0, 2).c_str() );
lat_min = atof( lat_str.substr(2).c_str() );
// lat dir
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lat_dir = msg.substr(begin, end - begin);
begin = end + 1;
lat = lat_deg + ( lat_min / 60.0 );
if ( lat_dir == "S" ) {
lat *= -1;
}
fdm->set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
// lon val
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lon_str = msg.substr(begin, end - begin);
begin = end + 1;
lon_deg = atof( lon_str.substr(0, 3).c_str() );
lon_min = atof( lon_str.substr(3).c_str() );
// lon dir
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lon_dir = msg.substr(begin, end - begin);
begin = end + 1;
lon = lon_deg + ( lon_min / 60.0 );
if ( lon_dir == "W" ) {
lon *= -1;
}
fdm->set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
#if 0
double sl_radius, lat_geoc;
sgGeodToGeoc( fdm->get_Latitude(),
fdm->get_Altitude(),
&sl_radius, &lat_geoc );
fdm->set_Geocentric_Position( lat_geoc,
fdm->get_Longitude(),
sl_radius + fdm->get_Altitude() );
#endif
// speed
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string speed_str = msg.substr(begin, end - begin);
begin = end + 1;
speed = atof( speed_str.c_str() );
fdm->set_V_calibrated_kts( speed );
// fdm->set_V_ground_speed( speed );
SG_LOG( SG_IO, SG_INFO, " speed = " << speed );
// heading
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string hdg_str = msg.substr(begin, end - begin);
begin = end + 1;
heading = atof( hdg_str.c_str() );
fdm->set_Euler_Angles( fdm->get_Phi(),
fdm->get_Theta(),
heading * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " heading = " << heading );
} else if ( sentence == "PGRMZ" ) {
// altitude
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string alt_str = msg.substr(begin, end - begin);
altitude = atof( alt_str.c_str() );
begin = end + 1;
// altitude units
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string alt_units = msg.substr(begin, end - begin);
begin = end + 1;
if ( alt_units != "F" && alt_units != "f" ) {
altitude *= SG_METER_TO_FEET;
}
fdm->set_Altitude( altitude );
SG_LOG( SG_IO, SG_INFO, " altitude = " << altitude );
}
begin = begin_line;
end_line = msg.find("\n", begin_line);
// $PGRMZ,AAAA.A,F,T*XX
if (mMetric)
sprintf( nmea, "$PGRMZ,%.1f,M,3", altitude_ft * SG_FEET_TO_METER );
else
sprintf( nmea, "$PGRMZ,%.1f,F,3", altitude_ft );
add_with_checksum(nmea, 256);
}
return true;
}
// process a Garmin sentence
void FGGarmin::parse_message(const std::vector<std::string>& tokens)
{
if (tokens[0] == "PGRMZ")
{
if (tokens.size()<3)
return;
// open hailing frequencies
bool FGGarmin::open() {
if ( is_enabled() ) {
SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
<< "is already in use, ignoring" );
return false;
// #1: altitude
double altitude = atof( tokens[1].c_str() );
// #2: altitude units
const string& alt_units = tokens[2];
if ( alt_units != "F" && alt_units != "f" )
altitude *= SG_METER_TO_FEET;
mFdm.set_Altitude( altitude );
SG_LOG( SG_IO, SG_DEBUG, " altitude = " << altitude );
}
SGIOChannel *io = get_io_channel();
if ( ! io->open( get_direction() ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
return false;
else
{
// not a Garmin message. Maybe standard NMEA message.
FGNMEA::parse_message(tokens);
}
set_enabled( true );
return true;
}
// process work for this port
bool FGGarmin::process() {
SGIOChannel *io = get_io_channel();
if ( get_direction() == SG_IO_OUT ) {
gen_message();
if ( ! io->write( buf, length ) ) {
SG_LOG( SG_IO, SG_WARN, "Error writing data." );
return false;
}
} else if ( get_direction() == SG_IO_IN ) {
if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
if ( parse_message() ) {
SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
} else {
SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
}
} else {
SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
return false;
}
if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
if ( parse_message() ) {
SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
} else {
SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
}
} else {
SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
return false;
}
}
return true;
}
// close the channel
bool FGGarmin::close() {
SGIOChannel *io = get_io_channel();
set_enabled( false );
if ( ! io->close() ) {
return false;
}
return true;
}

42
src/Network/garmin.hxx
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@ -1,4 +1,4 @@
// garmin.hxx -- Garmin protocal class
// garmin.hxx -- Garmin protocol class
//
// Written by Curtis Olson, started November 1999.
//
@ -20,44 +20,36 @@
//
// $Id$
#ifndef _FG_GARMIN_HXX
#define _FG_GARMIN_HXX
#include "nmea.hxx"
#include <simgear/compiler.h>
namespace NMEA
{
// Garmin proprietary messages
namespace GARMIN
{
const unsigned int PGRMZ = (1<<0);
}
}
#include <string>
#include "protocol.hxx"
class FGGarmin : public FGNMEA {
class FlightProperties;
class FGGarmin : public FGProtocol {
protected:
unsigned int mGarminMessages;
bool mMetric;
char buf[ FG_MAX_MSG_SIZE ];
int length;
FlightProperties* fdm;
// process a Garmin sentence
virtual void parse_message(const std::vector<std::string>& tokens);
public:
FGGarmin();
~FGGarmin();
bool gen_message();
bool parse_message();
// open hailing frequencies
bool open();
// process work for this port
bool process();
// close the channel
bool close();
virtual bool gen_message();
};
#endif // _FG_GARMIN_HXX

701
src/Network/nmea.cxx
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@ -1,4 +1,4 @@
// nmea.cxx -- NMEA protocal class
// nmea.cxx -- NMEA protocol class
//
// Written by Curtis Olson, started November 1999.
//
@ -39,464 +39,338 @@
#include "nmea.hxx"
FGNMEA::FGNMEA() {
fdm = new FlightProperties();
FGNMEA::FGNMEA() :
mLength(0),
mNmeaMessages(NMEA::SET),
mLineFeed("\n")
{
}
FGNMEA::~FGNMEA() {
delete fdm;
}
// calculate the nmea check sum
static char calc_nmea_cksum(char *sentence) {
// calculate the NMEA check sum
void FGNMEA::add_with_checksum(char *sentence, unsigned int buf_size) {
unsigned int i;
unsigned char sum = 0;
int i, len;
// cout << sentence << endl;
len = strlen(sentence);
sum = sentence[0];
for ( i = 1; i < len; i++ ) {
// cout << sentence[i];
for (i = 1; sentence[i] != 0; i++ ) {
sum ^= sentence[i];
}
// cout << endl;
// printf("sum = %02x\n", sum);
return sum;
if (i + 6 < buf_size)
snprintf( &sentence[i], 6, "*%02X%s", sum, mLineFeed);
SG_LOG( SG_IO, SG_DEBUG, sentence );
mNmeaSentence += sentence;
}
// generate NMEA message
bool FGNMEA::gen_message() {
// cout << "generating nmea message" << endl;
char rmc[256], gga[256], gsa[256];
char rmc_sum[10], gga_sum[10];
bool FGNMEA::gen_message()
{
char dir;
int deg;
double min;
char nmea[256];
SGTime *t = globals->get_time_params();
char utc[10];
sprintf( utc, "%02d%02d%02d",
t->getGmt()->tm_hour, t->getGmt()->tm_min, t->getGmt()->tm_sec );
t->getGmt()->tm_hour, t->getGmt()->tm_min, t->getGmt()->tm_sec );
char gga_lat[20], rmc_lat[20];
double latd = fdm->get_Latitude() * SGD_RADIANS_TO_DEGREES;
if ( latd < 0.0 ) {
latd = -latd;
dir = 'S';
} else {
dir = 'N';
char lat[20];
{
double latd = mFdm.get_Latitude() * SGD_RADIANS_TO_DEGREES;
if ( latd < 0.0 ) {
latd = -latd;
dir = 'S';
} else {
dir = 'N';
}
deg = (int)(latd);
min = (latd - (double)deg) * 60.0;
sprintf( lat, "%02d%07.4f,%c", abs(deg), min, dir);
}
deg = (int)(latd);
min = (latd - (double)deg) * 60.0;
sprintf( gga_lat, "%02d%07.4f,%c", abs(deg), min, dir);
sprintf( rmc_lat, "%02d%07.4f,%c", abs(deg), min, dir);
char gga_lon[20], rmc_lon[20];
double lond = fdm->get_Longitude() * SGD_RADIANS_TO_DEGREES;
if ( lond < 0.0 ) {
lond = -lond;
dir = 'W';
} else {
dir = 'E';
char lon[20];
{
double lond = mFdm.get_Longitude() * SGD_RADIANS_TO_DEGREES;
if ( lond < 0.0 ) {
lond = -lond;
dir = 'W';
} else {
dir = 'E';
}
deg = (int)(lond);
min = (lond - (double)deg) * 60.0;
sprintf( lon, "%03d%07.4f,%c", abs(deg), min, dir);
}
deg = (int)(lond);
min = (lond - (double)deg) * 60.0;
sprintf( gga_lon, "%03d%07.4f,%c", abs(deg), min, dir);
sprintf( rmc_lon, "%03d%07.4f,%c", abs(deg), min, dir);
double vn = fgGetDouble( "/velocities/speed-north-fps" );
double ve = fgGetDouble( "/velocities/speed-east-fps" );
double fps = sqrt( vn*vn + ve*ve );
double mps = fps * SG_FEET_TO_METER;
double kts = mps * SG_METER_TO_NM * 3600;
char speed[10];
sprintf( speed, "%.1f", kts );
double hdg_true = atan2( ve, vn ) * SGD_RADIANS_TO_DEGREES;
if ( hdg_true < 0 ) {
hdg_true += 360.0;
{
double fps = sqrt( vn*vn + ve*ve );
double mps = fps * SG_FEET_TO_METER;
double kts = mps * SG_METER_TO_NM * 3600;
sprintf( speed, "%.1f", kts );
}
char heading[10];
sprintf( heading, "%.1f", hdg_true );
char altitude_m[10];
sprintf( altitude_m, "%.1f",
fdm->get_Altitude() * SG_FEET_TO_METER );
char heading[10];
{
double hdg_true = atan2( ve, vn ) * SGD_RADIANS_TO_DEGREES;
if ( hdg_true < 0 ) {
hdg_true += 360.0;
}
sprintf( heading, "%.1f", hdg_true );
}
double altitude_ft = mFdm.get_Altitude();
char date[10];
int year = t->getGmt()->tm_year;
while ( year >= 100 ) { year -= 100; }
sprintf( date, "%02d%02d%02d", t->getGmt()->tm_mday,
t->getGmt()->tm_mon+1, year );
{
int year = t->getGmt()->tm_year;
while ( year >= 100 ) { year -= 100; }
sprintf( date, "%02d%02d%02d", t->getGmt()->tm_mday,
t->getGmt()->tm_mon+1, year );
}
char magvar[10];
float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
if ( magdeg < 0.0 ) {
magdeg = -magdeg;
dir = 'W';
} else {
dir = 'E';
{
float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
if ( magdeg < 0.0 ) {
magdeg = -magdeg;
dir = 'W';
} else {
dir = 'E';
}
sprintf( magvar, "%.1f,%c", magdeg, dir );
}
sprintf( magvar, "%.1f,%c", magdeg, dir );
// $GPRMC,HHMMSS,A,DDMM.MMMM,N,DDDMM.MMMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E,A*XX
sprintf( rmc, "GPRMC,%s,A,%s,%s,%s,%s,%s,%s,A",
utc, rmc_lat, rmc_lon, speed, heading, date, magvar );
sprintf( rmc_sum, "%02X", calc_nmea_cksum(rmc) );
// $GPGGA,HHMMSS,DDMM.MMMM,N,DDDMM.MMMM,W,1,NN,H.H,AAAA.A,M,GG.G,M,,*XX
sprintf( gga, "GPGGA,%s,%s,%s,1,08,0.9,%s,M,0.0,M,,",
utc, gga_lat, gga_lon, altitude_m );
sprintf( gga_sum, "%02X", calc_nmea_cksum(gga) );
sprintf( gsa, "%s",
"$GPGSA,A,3,01,02,03,,05,,07,,09,,11,12,0.9,0.9,2.0*38" );
SG_LOG( SG_IO, SG_DEBUG, rmc );
SG_LOG( SG_IO, SG_DEBUG, gga );
SG_LOG( SG_IO, SG_DEBUG, gsa );
string nmea_sentence;
// RMC sentence
nmea_sentence = "$";
nmea_sentence += rmc;
nmea_sentence += "*";
nmea_sentence += rmc_sum;
nmea_sentence += "\n";
if (mNmeaMessages & NMEA::GPRMC)
{
// $GPRMC,HHMMSS,A,DDMM.MMMM,N,DDDMM.MMMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E,A*XX
sprintf( nmea, "$GPRMC,%s,A,%s,%s,%s,%s,%s,%s,A",
utc, lat, lon, speed, heading, date, magvar );
add_with_checksum(nmea, 256);
}
// GGA sentence
nmea_sentence += "$";
nmea_sentence += gga;
nmea_sentence += "*";
nmea_sentence += gga_sum;
nmea_sentence += "\n";
if (mNmeaMessages & NMEA::GPGGA)
{
// $GPGGA,HHMMSS,DDMM.MMMM,N,DDDMM.MMMM,W,1,NN,H.H,AAAA.A,M,GG.G,M,,*XX
sprintf( nmea, "$GPGGA,%s,%s,%s,1,08,0.9,%.1f,M,0.0,M,,",
utc, lat, lon, altitude_ft * SG_FEET_TO_METER );
add_with_checksum(nmea, 256);
}
// GSA sentence (totally faked)
nmea_sentence += gsa;
nmea_sentence += "\n";
if (mNmeaMessages & NMEA::GPGSA)
{
sprintf( nmea, "%s%s",
"$GPGSA,A,3,01,02,03,,05,,07,,09,,11,12,0.9,0.9,2.0*38", mLineFeed );
SG_LOG( SG_IO, SG_DEBUG, nmea );
// cout << nmea_sentence;
length = nmea_sentence.length();
strncpy( buf, nmea_sentence.c_str(), length );
mNmeaSentence += nmea;
}
return true;
}
// parse NMEA message. messages will look something like the
// following:
//
// $GPRMC,163227,A,3321.173,N,11039.855,W,000.1,270.0,171199,0.000,E*61
// $GPGGA,163227,3321.173,N,11039.855,W,1,,,3333,F,,,,*0F
bool FGNMEA::parse_message() {
SG_LOG( SG_IO, SG_INFO, "parse nmea message" );
void FGNMEA::parse_line() {
SG_LOG( SG_IO, SG_DEBUG, "parse nmea message" );
string msg = buf;
msg = msg.substr( 0, length );
SG_LOG( SG_IO, SG_INFO, "entire message = " << msg );
if (mLength > FG_MAX_MSG_SIZE-1)
mLength = FG_MAX_MSG_SIZE-1;
string::size_type begin_line, end_line, begin, end;
begin_line = begin = 0;
SG_LOG( SG_IO, SG_DEBUG, "entire message = " << mBuf );
// extract out each line
end_line = msg.find("\n", begin_line);
while ( end_line != string::npos ) {
string line = msg.substr(begin_line, end_line - begin_line);
begin_line = end_line + 1;
SG_LOG( SG_IO, SG_INFO, " input line = " << line );
// leading character
string start = msg.substr(begin, 1);
++begin;
SG_LOG( SG_IO, SG_INFO, " start = " << start );
// sentence
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string sentence = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " sentence = " << sentence );
double lon_deg, lon_min, lat_deg, lat_min;
double lon, lat, speed, heading, altitude;
if ( sentence == "GPRMC" ) {
// time
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string utc = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
// junk
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string junk = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
// lat val
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lat_str = msg.substr(begin, end - begin);
begin = end + 1;
lat_deg = atof( lat_str.substr(0, 2).c_str() );
lat_min = atof( lat_str.substr(2).c_str() );
// lat dir
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lat_dir = msg.substr(begin, end - begin);
begin = end + 1;
lat = lat_deg + ( lat_min / 60.0 );
if ( lat_dir == "S" ) {
lat *= -1;
}
fdm->set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
// lon val
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lon_str = msg.substr(begin, end - begin);
begin = end + 1;
lon_deg = atof( lon_str.substr(0, 3).c_str() );
lon_min = atof( lon_str.substr(3).c_str() );
// lon dir
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lon_dir = msg.substr(begin, end - begin);
begin = end + 1;
lon = lon_deg + ( lon_min / 60.0 );
if ( lon_dir == "W" ) {
lon *= -1;
}
fdm->set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
#if 0
double sl_radius, lat_geoc;
sgGeodToGeoc( fdm->get_Latitude(),
fdm->get_Altitude(),
&sl_radius, &lat_geoc );
fdm->set_Geocentric_Position( lat_geoc,
fdm->get_Longitude(),
sl_radius + fdm->get_Altitude() );
#endif
// speed
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string speed_str = msg.substr(begin, end - begin);
begin = end + 1;
speed = atof( speed_str.c_str() );
fdm->set_V_calibrated_kts( speed );
// fdm->set_V_ground_speed( speed );
SG_LOG( SG_IO, SG_INFO, " speed = " << speed );
// heading
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string hdg_str = msg.substr(begin, end - begin);
begin = end + 1;
heading = atof( hdg_str.c_str() );
fdm->set_Euler_Angles( fdm->get_Phi(),
fdm->get_Theta(),
heading * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " heading = " << heading );
} else if ( sentence == "GPGGA" ) {
// time
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string utc = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
// lat val
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lat_str = msg.substr(begin, end - begin);
begin = end + 1;
lat_deg = atof( lat_str.substr(0, 2).c_str() );
lat_min = atof( lat_str.substr(2).c_str() );
// lat dir
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lat_dir = msg.substr(begin, end - begin);
begin = end + 1;
lat = lat_deg + ( lat_min / 60.0 );
if ( lat_dir == "S" ) {
lat *= -1;
}
// fdm->set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
// lon val
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lon_str = msg.substr(begin, end - begin);
begin = end + 1;
lon_deg = atof( lon_str.substr(0, 3).c_str() );
lon_min = atof( lon_str.substr(3).c_str() );
// lon dir
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string lon_dir = msg.substr(begin, end - begin);
begin = end + 1;
lon = lon_deg + ( lon_min / 60.0 );
if ( lon_dir == "W" ) {
lon *= -1;
}
// fdm->set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
// junk
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string junk = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
// junk
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
junk = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
// junk
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
junk = msg.substr(begin, end - begin);
begin = end + 1;
SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
// altitude
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string alt_str = msg.substr(begin, end - begin);
altitude = atof( alt_str.c_str() );
begin = end + 1;
// altitude units
end = msg.find(",", begin);
if ( end == string::npos ) {
return false;
}
string alt_units = msg.substr(begin, end - begin);
begin = end + 1;
if ( alt_units != "F" ) {
altitude *= SG_METER_TO_FEET;
}
fdm->set_Altitude( altitude );
SG_LOG( SG_IO, SG_INFO, " altitude = " << altitude );
}
// printf("%.8f %.8f\n", lon, lat);
begin = begin_line;
end_line = msg.find("\n", begin_line);
// test leading character
if (mBuf[0] != '$')
{
SG_LOG( SG_IO, SG_DEBUG, " invalid NMEA start character = " << mBuf[0]);
return;
}
return true;
// get rid of checksum and "*" delimiter
while ((mLength > 0)&&(mBuf[mLength]!='*'))
{
mLength--;
}
mBuf[mLength] = 0;
// split string to tokens
std::vector<std::string> tokens;
for (unsigned int pos=1;pos < mLength;pos++)
{
const char* pCurrent = &mBuf[pos];
while ((mBuf[pos]!=',')&&(pos<mLength))
pos++;
if (mBuf[pos]==',')
mBuf[pos] = 0;
tokens.push_back(pCurrent);
}
if (tokens.size() == 0)
return;
if (tokens.size()>1)
{
for (unsigned int i=0;i<tokens.size();i++)
{
SG_LOG( SG_IO, SG_DEBUG, " NMEA token # " << i << ": " << tokens[i]);
}
parse_message(tokens);
}
}
void FGNMEA::parse_message(const std::vector<std::string>& tokens)
{
double lon_deg, lon_min, lat_deg, lat_min;
double lon, lat;
string::size_type begin = 0, end;
if (tokens[0] == "GPRMC" ) {
// $GPRMC,HHMMSS,A,DDMM.MMMM,N,DDDMM.MMMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E,A*XX
if ( tokens.size()<9)
return;
// #1: time
const string& utc = tokens[1];
SG_LOG( SG_IO, SG_DEBUG, " utc = " << utc );
// #2: junk
SG_LOG( SG_IO, SG_DEBUG, " junk = " << tokens[2] );
// #3: lat val
lat_deg = atof( tokens[3].substr(0, 2).c_str() );
lat_min = atof( tokens[3].substr(2).c_str() );
lat = lat_deg + ( lat_min / 60.0 );
// #4: lat dir
if ( tokens[4] == "S" )
lat *= -1;
mFdm.set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
// #5: lon val
lon_deg = atof( tokens[5].substr(0, 3).c_str() );
lon_min = atof( tokens[5].substr(3).c_str() );
lon = lon_deg + ( lon_min / 60.0 );
// #6: lon dir
if ( tokens[6] == "W" )
lon *= -1;
mFdm.set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_DEBUG, " lat = " << lat << ", lon = " << lon );
#if 0
double sl_radius, lat_geoc;
sgGeodToGeoc( mFdm.get_Latitude(),
mFdm.get_Altitude(),
&sl_radius, &lat_geoc );
mFdm.set_Geocentric_Position( lat_geoc,
mFdm.get_Longitude(),
sl_radius + mFdm.get_Altitude() );
#endif
// #7: speed
double speed = atof( tokens[7].c_str() );
mFdm.set_V_calibrated_kts( speed );
// mFdm.set_V_ground_speed( speed );
SG_LOG( SG_IO, SG_DEBUG, " speed = " << speed );
// #8: heading
double heading = atof( tokens[8].c_str() );
mFdm.set_Euler_Angles( mFdm.get_Phi(),
mFdm.get_Theta(),
heading * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_DEBUG, " heading = " << heading );
} else
if (tokens[0] == "GPGGA" ) {
if ( tokens.size()<11)
return;
// #1: time
const string& utc = tokens[1];
SG_LOG( SG_IO, SG_DEBUG, " utc = " << utc );
// #2: lat val
lat_deg = atof( tokens[2].substr(0, 2).c_str() );
lat_min = atof( tokens[2].substr(2).c_str() );
lat = lat_deg + ( lat_min / 60.0 );
// #3: lat dir
if ( tokens[4] == "S" )
lat *= -1;
mFdm.set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
// #4: lon val
lon_deg = atof( tokens[4].substr(0, 3).c_str() );
lon_min = atof( tokens[4].substr(3).c_str() );
lon = lon_deg + ( lon_min / 60.0 );
// #5: lon dir
if ( tokens[5] == "W" )
lon *= -1;
mFdm.set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
SG_LOG( SG_IO, SG_DEBUG, " lat = " << lat << ", lon = " << lon );
// #6: junk
SG_LOG( SG_IO, SG_DEBUG, " junk = " << tokens[6] );
// #7: junk
SG_LOG( SG_IO, SG_DEBUG, " junk = " << tokens[7] );
// #8: junk
SG_LOG( SG_IO, SG_DEBUG, " junk = " << tokens[8] );
// #9: altitude
double altitude = atof( tokens[9].c_str() );
// #10: altitude unit
const string& alt_units = tokens[10];
if ( alt_units != "F" && alt_units != "f" ) {
altitude *= SG_METER_TO_FEET;
}
mFdm.set_Altitude( altitude );
SG_LOG( SG_IO, SG_DEBUG, " altitude = " << altitude );
}
}
// open hailing frequencies
bool FGNMEA::open() {
if ( is_enabled() ) {
SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
<< "is already in use, ignoring" );
return false;
SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
<< "is already in use, ignoring" );
return false;
}
SGIOChannel *io = get_io_channel();
if ( ! io->open( get_direction() ) ) {
SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
return false;
SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
return false;
}
set_enabled( true );
@ -509,28 +383,33 @@ bool FGNMEA::open() {
bool FGNMEA::process() {
SGIOChannel *io = get_io_channel();
if ( get_direction() == SG_IO_OUT ) {
gen_message();
if ( ! io->write( buf, length ) ) {
SG_LOG( SG_IO, SG_WARN, "Error writing data." );
return false;
}
} else if ( get_direction() == SG_IO_IN ) {
if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
parse_message();
} else {
SG_LOG( SG_IO, SG_WARN, "Error reading data." );
return false;
}
if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
parse_message();
} else {
SG_LOG( SG_IO, SG_WARN, "Error reading data." );
return false;
}
if ( get_direction() == SG_IO_OUT )
{
// process output
gen_message();
if ((!mNmeaSentence.empty())&&
(!io->write( mNmeaSentence.c_str(), mNmeaSentence.length() )))
{
SG_LOG( SG_IO, SG_WARN, "Error writing data." );
}
mNmeaSentence = "";
}
else
if ( get_direction() == SG_IO_IN )
{
// process input lines (up to two lines per cycle)
for (int i=0;i<2;i++)
{
if ( (mLength = io->readline( mBuf, FG_MAX_MSG_SIZE )) > 0 ) {
parse_line();
} else {
printf("Error reading data!\n");
SG_LOG( SG_IO, SG_WARN, "Error reading data." );
}
}
}
return true;
return true; // return value is unused
}
@ -540,9 +419,5 @@ bool FGNMEA::close() {
set_enabled( false );
if ( ! io->close() ) {
return false;
}
return true;
return io->close();
}

52
src/Network/nmea.hxx
View file

@ -1,4 +1,4 @@
// nmea.hxx -- NMEA protocal class
// nmea.hxx -- NMEA protocol class
//
// Written by Curtis Olson, started November 1999.
//
@ -24,7 +24,6 @@
#ifndef _FG_NMEA_HXX
#define _FG_NMEA_HXX
#include <simgear/compiler.h>
#include <string>
@ -33,30 +32,49 @@
class FlightProperties;
namespace NMEA
{
// supported NMEA messages
const unsigned int GPRMC = (1<<0);
const unsigned int GPGGA = (1<<1);
const unsigned int GPGSA = (1<<2);
const unsigned int SET = (GPRMC|GPGGA|GPGSA);
}
class FGNMEA : public FGProtocol {
char buf[ FG_MAX_MSG_SIZE ];
int length;
FlightProperties* fdm;
protected:
char mBuf[FG_MAX_MSG_SIZE];
unsigned int mLength;
unsigned int mNmeaMessages;
FlightProperties mFdm;
const char* mLineFeed;
string mNmeaSentence;
void add_with_checksum(char *sentence, unsigned int buf_size);
// process a single NMEA line
void parse_line();
// generate output message(s)
virtual bool gen_message();
// process a single NMEA sentence
virtual void parse_message(const std::vector<std::string>& tokens);
public:
FGNMEA();
~FGNMEA();
bool gen_message();
bool parse_message();
FGNMEA();
~FGNMEA();
// open hailing frequencies
bool open();
virtual bool open();
// process work for this port
bool process();
virtual bool process();
// close the channel
bool close();
virtual bool close();
};
#endif // _FG_NMEA_HXX