1 // garmin.cxx -- Garmin protocal class
3 // Written by Curtis Olson, started November 1999.
5 // Copyright (C) 1999 Curtis L. Olson - http://www.flightgear.org/~curt
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
30 #include <simgear/debug/logstream.hxx>
31 #include <simgear/math/sg_geodesy.hxx>
32 #include <simgear/io/iochannel.hxx>
33 #include <simgear/timing/sg_time.hxx>
35 #include <FDM/flightProperties.hxx>
36 #include <Main/fg_props.hxx>
37 #include <Main/globals.hxx>
43 FGGarmin::FGGarmin() {
44 fdm = new FlightProperties;
47 FGGarmin::~FGGarmin() {
52 // calculate the garmin check sum
53 static char calc_nmea_cksum(char *sentence) {
54 unsigned char sum = 0;
57 // cout << sentence << endl;
59 len = strlen(sentence);
61 for ( i = 1; i < len; i++ ) {
62 // cout << sentence[i];
67 // printf("sum = %02x\n", sum);
72 // generate Garmin message
73 bool FGGarmin::gen_message() {
74 // cout << "generating garmin message" << endl;
76 char rmc[256], rmc_sum[256], rmz[256], rmz_sum[256], gsa[256];
81 SGTime *t = globals->get_time_params();
84 sprintf( utc, "%02d%02d%02d",
85 t->getGmt()->tm_hour, t->getGmt()->tm_min, t->getGmt()->tm_sec );
88 double latd = fdm->get_Latitude() * SGD_RADIANS_TO_DEGREES;
96 min = (latd - (double)deg) * 60.0;
97 sprintf( rmc_lat, "%02d%07.4f,%c", abs(deg), min, dir);
100 double lond = fdm->get_Longitude() * SGD_RADIANS_TO_DEGREES;
108 min = (lond - (double)deg) * 60.0;
109 sprintf( rmc_lon, "%03d%07.4f,%c", abs(deg), min, dir);
112 sprintf( speed, "%05.1f", fdm->get_V_equiv_kts() );
115 sprintf( heading, "%05.1f", fdm->get_Psi() * SGD_RADIANS_TO_DEGREES );
118 sprintf( altitude_m, "%02d",
119 (int)(fdm->get_Altitude() * SG_FEET_TO_METER) );
122 int year = t->getGmt()->tm_year;
123 while ( year >= 100 ) { year -= 100; }
124 sprintf( date, "%02d%02d%02d", t->getGmt()->tm_mday,
125 t->getGmt()->tm_mon+1, year );
128 float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
129 if ( magdeg < 0.0 ) {
135 sprintf( magvar, "%05.1f,%c", magdeg, dir );
137 // $GPRMC,HHMMSS,A,DDMM.MMMM,N,DDDMM.MMMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E*XX
138 sprintf( rmc, "GPRMC,%s,A,%s,%s,%s,%s,%s,%s",
139 utc, rmc_lat, rmc_lon, speed, heading, date, magvar );
140 sprintf( rmc_sum, "%02X", calc_nmea_cksum(rmc) );
142 // sprintf( gga, "$GPGGA,%s,%s,%s,1,04,0.0,%s,M,00.0,M,,*00\r\n",
143 // utc, lat, lon, altitude_m );
145 sprintf( rmz, "PGRMZ,%s,M,3", altitude_m );
146 sprintf( rmz_sum, "%02X", calc_nmea_cksum(rmz) );
149 "$GPGSA,A,3,01,02,03,,05,,07,,09,,11,12,0.9,0.9,2.0*38" );
151 SG_LOG( SG_IO, SG_DEBUG, rmc );
152 SG_LOG( SG_IO, SG_DEBUG, rmz );
153 SG_LOG( SG_IO, SG_DEBUG, gsa );
155 string garmin_sentence;
158 garmin_sentence = "$";
159 garmin_sentence += rmc;
160 garmin_sentence += "*";
161 garmin_sentence += rmc_sum;
162 garmin_sentence += "\r\n";
164 // RMZ sentence (garmin proprietary)
165 garmin_sentence += "$";
166 garmin_sentence += rmz;
167 garmin_sentence += "*";
168 garmin_sentence += rmz_sum;
169 garmin_sentence += "\r\n";
171 // GSA sentence (totally faked)
172 garmin_sentence += gsa;
173 garmin_sentence += "\r\n";
175 std::cout << garmin_sentence;
177 length = garmin_sentence.length();
178 strncpy( buf, garmin_sentence.c_str(), length );
184 // parse Garmin message
185 bool FGGarmin::parse_message() {
186 SG_LOG( SG_IO, SG_INFO, "parse garmin message" );
189 msg = msg.substr( 0, length );
190 SG_LOG( SG_IO, SG_INFO, "entire message = " << msg );
192 string::size_type begin_line, end_line, begin, end;
193 begin_line = begin = 0;
195 // extract out each line
196 end_line = msg.find("\n", begin_line);
197 while ( end_line != string::npos ) {
198 string line = msg.substr(begin_line, end_line - begin_line);
199 begin_line = end_line + 1;
200 SG_LOG( SG_IO, SG_INFO, " input line = " << line );
203 string start = msg.substr(begin, 1);
205 SG_LOG( SG_IO, SG_INFO, " start = " << start );
208 end = msg.find(",", begin);
209 if ( end == string::npos ) {
213 string sentence = msg.substr(begin, end - begin);
215 SG_LOG( SG_IO, SG_INFO, " sentence = " << sentence );
217 double lon_deg, lon_min, lat_deg, lat_min;
218 double lon, lat, speed, heading, altitude;
220 if ( sentence == "GPRMC" ) {
222 end = msg.find(",", begin);
223 if ( end == string::npos ) {
227 string utc = msg.substr(begin, end - begin);
229 SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
232 end = msg.find(",", begin);
233 if ( end == string::npos ) {
237 string junk = msg.substr(begin, end - begin);
239 SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
242 end = msg.find(",", begin);
243 if ( end == string::npos ) {
247 string lat_str = msg.substr(begin, end - begin);
250 lat_deg = atof( lat_str.substr(0, 2).c_str() );
251 lat_min = atof( lat_str.substr(2).c_str() );
254 end = msg.find(",", begin);
255 if ( end == string::npos ) {
259 string lat_dir = msg.substr(begin, end - begin);
262 lat = lat_deg + ( lat_min / 60.0 );
263 if ( lat_dir == "S" ) {
267 fdm->set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
268 SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
271 end = msg.find(",", begin);
272 if ( end == string::npos ) {
276 string lon_str = msg.substr(begin, end - begin);
279 lon_deg = atof( lon_str.substr(0, 3).c_str() );
280 lon_min = atof( lon_str.substr(3).c_str() );
283 end = msg.find(",", begin);
284 if ( end == string::npos ) {
288 string lon_dir = msg.substr(begin, end - begin);
291 lon = lon_deg + ( lon_min / 60.0 );
292 if ( lon_dir == "W" ) {
296 fdm->set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
297 SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
300 double sl_radius, lat_geoc;
301 sgGeodToGeoc( fdm->get_Latitude(),
303 &sl_radius, &lat_geoc );
304 fdm->set_Geocentric_Position( lat_geoc,
305 fdm->get_Longitude(),
306 sl_radius + fdm->get_Altitude() );
310 end = msg.find(",", begin);
311 if ( end == string::npos ) {
315 string speed_str = msg.substr(begin, end - begin);
317 speed = atof( speed_str.c_str() );
318 fdm->set_V_calibrated_kts( speed );
319 // fdm->set_V_ground_speed( speed );
320 SG_LOG( SG_IO, SG_INFO, " speed = " << speed );
323 end = msg.find(",", begin);
324 if ( end == string::npos ) {
328 string hdg_str = msg.substr(begin, end - begin);
330 heading = atof( hdg_str.c_str() );
331 fdm->set_Euler_Angles( fdm->get_Phi(),
333 heading * SGD_DEGREES_TO_RADIANS );
334 SG_LOG( SG_IO, SG_INFO, " heading = " << heading );
335 } else if ( sentence == "PGRMZ" ) {
337 end = msg.find(",", begin);
338 if ( end == string::npos ) {
342 string alt_str = msg.substr(begin, end - begin);
343 altitude = atof( alt_str.c_str() );
347 end = msg.find(",", begin);
348 if ( end == string::npos ) {
352 string alt_units = msg.substr(begin, end - begin);
355 if ( alt_units != "F" && alt_units != "f" ) {
356 altitude *= SG_METER_TO_FEET;
359 fdm->set_Altitude( altitude );
361 SG_LOG( SG_IO, SG_INFO, " altitude = " << altitude );
365 // printf("%.8f %.8f\n", lon, lat);
368 end_line = msg.find("\n", begin_line);
375 // open hailing frequencies
376 bool FGGarmin::open() {
377 if ( is_enabled() ) {
378 SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
379 << "is already in use, ignoring" );
383 SGIOChannel *io = get_io_channel();
385 if ( ! io->open( get_direction() ) ) {
386 SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
396 // process work for this port
397 bool FGGarmin::process() {
398 SGIOChannel *io = get_io_channel();
400 if ( get_direction() == SG_IO_OUT ) {
402 if ( ! io->write( buf, length ) ) {
403 SG_LOG( SG_IO, SG_WARN, "Error writing data." );
406 } else if ( get_direction() == SG_IO_IN ) {
407 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
408 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
409 if ( parse_message() ) {
410 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
412 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
415 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
418 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
419 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
420 if ( parse_message() ) {
421 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
423 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
426 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
436 bool FGGarmin::close() {
437 SGIOChannel *io = get_io_channel();
439 set_enabled( false );
441 if ( ! io->close() ) {