1 // AV400.cxx -- Garmin 400 series protocal class
3 // Written by Curtis Olson, started August 2006.
5 // Copyright (C) 2006 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.
28 #include <simgear/debug/logstream.hxx>
29 #include <simgear/math/sg_geodesy.hxx>
30 #include <simgear/io/iochannel.hxx>
31 #include <simgear/timing/sg_time.hxx>
33 #include <FDM/flight.hxx>
34 #include <Main/fg_props.hxx>
35 #include <Main/globals.hxx>
39 SG_USING_NAMESPACE(std);
48 // calculate the garmin check sum
49 static char calc_nmea_cksum(char *sentence) {
50 unsigned char sum = 0;
53 // cout << sentence << endl;
55 len = strlen(sentence);
57 for ( i = 1; i < len; i++ ) {
58 // cout << sentence[i];
63 // printf("sum = %02x\n", sum);
68 // generate AV400 message
69 bool FGAV400::gen_message() {
70 // cout << "generating garmin message" << endl;
72 char msg_z[32], msg_A[32], msg_B[32], msg_C[32], msg_D[32];
73 char msg_Q[32], msg_T[32], msg_type2[256];
74 // the following could be implemented, but currently are unused
75 // char msg_E[32], msg_G[32], msg_I[32], msg_K[32], msg_L[32], msg_S[32];
83 sprintf( msg_z, "z%05.0f\r\n", cur_fdm_state->get_Altitude() );
88 double latd = cur_fdm_state->get_Latitude() * SGD_RADIANS_TO_DEGREES;
96 min = (latd - (double)deg) * 60.0 * 100.0;
97 sprintf( msg_A, "A%c %02d %04.0f\r\n", dir, deg, min);
100 double lond = cur_fdm_state->get_Longitude() * SGD_RADIANS_TO_DEGREES;
108 min = (lond - (double)deg) * 60.0 * 100.0;
109 sprintf( msg_B, "B%c %03d %04.0f\r\n", dir, deg, min);
112 double vn = fgGetDouble( "/velocities/speed-north-fps" );
113 double ve = fgGetDouble( "/velocities/speed-east-fps" );
114 double gnd_trk_true = atan2( ve, vn ) * SGD_RADIANS_TO_DEGREES;
115 if ( gnd_trk_true < 0.0 ) { gnd_trk_true += 360.0; }
116 sprintf( msg_C, "C%03.0f\r\n", gnd_trk_true);
119 double speed_kt = sqrt( vn*vn + ve*ve ) * SG_FPS_TO_KT;
120 if ( speed_kt > 999.0 ) {
123 sprintf( msg_D, "D%03.0f\r\n", speed_kt);
125 // create msg_E (not implemented)
126 // create msg_G (not implemented)
127 // create msg_I (not implemented)
128 // create msg_K (not implemented)
129 // create msg_L (not implemented)
132 float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
133 if ( magdeg < 0.0 ) {
139 sprintf( msg_Q, "Q%c%03.0f\r\n", dir, magdeg * 10.0 );
141 // create msg_S (not implemented)
144 sprintf( msg_T, "T---------\r\n" );
146 // create msg_l (not implemented)
149 sprintf( msg_type2, "w01%c\r\n", (char)65 );
153 sentence += '\002'; // STX
154 sentence += msg_z; // altitude
155 sentence += msg_A; // latitude
156 sentence += msg_B; // longitude
157 sentence += msg_C; // ground track
158 sentence += msg_D; // ground speed (kt)
159 sentence += "E-----\r\n";
160 sentence += "G-----\r\n";
161 sentence += "I----\r\n";
162 sentence += "K-----\r\n";
163 sentence += "L----\r\n";
164 sentence += msg_Q; // magvar
165 sentence += "S-----\r\n";
166 sentence += msg_T; // end of type 1 messages (must be sent)
167 sentence += msg_type2; // type2 message
168 sentence += "l------\r\n";
169 sentence += '\003'; // ETX
173 length = sentence.length();
174 strncpy( buf, sentence.c_str(), length );
180 // parse AV400 message
181 bool FGAV400::parse_message() {
182 SG_LOG( SG_IO, SG_INFO, "parse garmin message" );
185 msg = msg.substr( 0, length );
186 SG_LOG( SG_IO, SG_INFO, "entire message = " << msg );
188 string::size_type begin_line, end_line, begin, end;
189 begin_line = begin = 0;
191 // extract out each line
192 end_line = msg.find("\n", begin_line);
193 while ( end_line != string::npos ) {
194 string line = msg.substr(begin_line, end_line - begin_line);
195 begin_line = end_line + 1;
196 SG_LOG( SG_IO, SG_INFO, " input line = " << line );
199 string start = msg.substr(begin, 1);
201 SG_LOG( SG_IO, SG_INFO, " start = " << start );
204 end = msg.find(",", begin);
205 if ( end == string::npos ) {
209 string sentence = msg.substr(begin, end - begin);
211 SG_LOG( SG_IO, SG_INFO, " sentence = " << sentence );
213 double lon_deg, lon_min, lat_deg, lat_min;
214 double lon, lat, speed, heading, altitude;
216 if ( sentence == "GPRMC" ) {
218 end = msg.find(",", begin);
219 if ( end == string::npos ) {
223 string utc = msg.substr(begin, end - begin);
225 SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
228 end = msg.find(",", begin);
229 if ( end == string::npos ) {
233 string junk = msg.substr(begin, end - begin);
235 SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
238 end = msg.find(",", begin);
239 if ( end == string::npos ) {
243 string lat_str = msg.substr(begin, end - begin);
246 lat_deg = atof( lat_str.substr(0, 2).c_str() );
247 lat_min = atof( lat_str.substr(2).c_str() );
250 end = msg.find(",", begin);
251 if ( end == string::npos ) {
255 string lat_dir = msg.substr(begin, end - begin);
258 lat = lat_deg + ( lat_min / 60.0 );
259 if ( lat_dir == "S" ) {
263 cur_fdm_state->set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
264 SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
267 end = msg.find(",", begin);
268 if ( end == string::npos ) {
272 string lon_str = msg.substr(begin, end - begin);
275 lon_deg = atof( lon_str.substr(0, 3).c_str() );
276 lon_min = atof( lon_str.substr(3).c_str() );
279 end = msg.find(",", begin);
280 if ( end == string::npos ) {
284 string lon_dir = msg.substr(begin, end - begin);
287 lon = lon_deg + ( lon_min / 60.0 );
288 if ( lon_dir == "W" ) {
292 cur_fdm_state->set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
293 SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
296 double sl_radius, lat_geoc;
297 sgGeodToGeoc( cur_fdm_state->get_Latitude(),
298 cur_fdm_state->get_Altitude(),
299 &sl_radius, &lat_geoc );
300 cur_fdm_state->set_Geocentric_Position( lat_geoc,
301 cur_fdm_state->get_Longitude(),
302 sl_radius + cur_fdm_state->get_Altitude() );
306 end = msg.find(",", begin);
307 if ( end == string::npos ) {
311 string speed_str = msg.substr(begin, end - begin);
313 speed = atof( speed_str.c_str() );
314 cur_fdm_state->set_V_calibrated_kts( speed );
315 // cur_fdm_state->set_V_ground_speed( speed );
316 SG_LOG( SG_IO, SG_INFO, " speed = " << speed );
319 end = msg.find(",", begin);
320 if ( end == string::npos ) {
324 string hdg_str = msg.substr(begin, end - begin);
326 heading = atof( hdg_str.c_str() );
327 cur_fdm_state->set_Euler_Angles( cur_fdm_state->get_Phi(),
328 cur_fdm_state->get_Theta(),
329 heading * SGD_DEGREES_TO_RADIANS );
330 SG_LOG( SG_IO, SG_INFO, " heading = " << heading );
331 } else if ( sentence == "PGRMZ" ) {
333 end = msg.find(",", begin);
334 if ( end == string::npos ) {
338 string alt_str = msg.substr(begin, end - begin);
339 altitude = atof( alt_str.c_str() );
343 end = msg.find(",", begin);
344 if ( end == string::npos ) {
348 string alt_units = msg.substr(begin, end - begin);
351 if ( alt_units != "F" && alt_units != "f" ) {
352 altitude *= SG_METER_TO_FEET;
355 cur_fdm_state->set_Altitude( altitude );
357 SG_LOG( SG_IO, SG_INFO, " altitude = " << altitude );
361 // printf("%.8f %.8f\n", lon, lat);
364 end_line = msg.find("\n", begin_line);
371 // open hailing frequencies
372 bool FGAV400::open() {
373 if ( is_enabled() ) {
374 SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
375 << "is already in use, ignoring" );
379 SGIOChannel *io = get_io_channel();
381 if ( ! io->open( get_direction() ) ) {
382 SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
392 // process work for this port
393 bool FGAV400::process() {
394 SGIOChannel *io = get_io_channel();
396 if ( get_direction() == SG_IO_OUT ) {
398 if ( ! io->write( buf, length ) ) {
399 SG_LOG( SG_IO, SG_WARN, "Error writing data." );
402 } else if ( get_direction() == SG_IO_IN ) {
403 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
404 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
405 if ( parse_message() ) {
406 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
408 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
411 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
414 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
415 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
416 if ( parse_message() ) {
417 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
419 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
422 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
432 bool FGAV400::close() {
433 SGIOChannel *io = get_io_channel();
435 set_enabled( false );
437 if ( ! io->close() ) {