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>
47 // calculate the garmin check sum
48 static char calc_nmea_cksum(char *sentence) {
49 unsigned char sum = 0;
52 // cout << sentence << endl;
54 len = strlen(sentence);
56 for ( i = 1; i < len; i++ ) {
57 // cout << sentence[i];
62 // 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 float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
113 double vn = fgGetDouble( "/velocities/speed-north-fps" );
114 double ve = fgGetDouble( "/velocities/speed-east-fps" );
115 double gnd_trk_true = atan2( ve, vn ) * SGD_RADIANS_TO_DEGREES;
116 double gnd_trk_mag = gnd_trk_true - magdeg;
117 if ( gnd_trk_mag < 0.0 ) { gnd_trk_mag += 360.0; }
118 if ( gnd_trk_mag >= 360.0 ) { gnd_trk_mag -= 360.0; }
119 sprintf( msg_C, "C%03.0f\r\n", gnd_trk_mag);
122 double speed_kt = sqrt( vn*vn + ve*ve ) * SG_FPS_TO_KT;
123 if ( speed_kt > 999.0 ) {
126 sprintf( msg_D, "D%03.0f\r\n", speed_kt);
128 // create msg_E (not implemented)
129 // create msg_G (not implemented)
130 // create msg_I (not implemented)
131 // create msg_K (not implemented)
132 // create msg_L (not implemented)
135 if ( magdeg < 0.0 ) {
141 sprintf( msg_Q, "Q%c%03.0f\r\n", dir, magdeg * 10.0 );
143 // create msg_S (not implemented)
146 sprintf( msg_T, "T---------\r\n" );
148 // create msg_l (not implemented)
151 sprintf( msg_type2, "w01%c\r\n", (char)65 );
155 sentence += '\002'; // STX
156 sentence += msg_z; // altitude
157 sentence += msg_A; // latitude
158 sentence += msg_B; // longitude
159 sentence += msg_C; // ground track
160 sentence += msg_D; // ground speed (kt)
161 // sentence += "E-----\r\n";
162 // sentence += "G-----\r\n";
163 // sentence += "I----\r\n";
164 // sentence += "K-----\r\n";
165 // sentence += "L----\r\n";
166 sentence += msg_Q; // magvar
167 // sentence += "S-----\r\n";
168 sentence += msg_T; // end of type 1 messages (must be sent)
169 sentence += msg_type2; // type2 message
170 // sentence += "l------\r\n";
171 sentence += '\003'; // ETX
174 length = sentence.length();
175 // cout << endl << "length = " << length << endl;
176 strncpy( buf, sentence.c_str(), length );
182 // parse AV400 message
183 bool FGAV400::parse_message() {
184 SG_LOG( SG_IO, SG_INFO, "parse garmin message" );
187 msg = msg.substr( 0, length );
188 SG_LOG( SG_IO, SG_INFO, "entire message = " << msg );
190 string::size_type begin_line, end_line, begin, end;
191 begin_line = begin = 0;
193 // extract out each line
194 end_line = msg.find("\n", begin_line);
195 while ( end_line != string::npos ) {
196 string line = msg.substr(begin_line, end_line - begin_line);
197 begin_line = end_line + 1;
198 SG_LOG( SG_IO, SG_INFO, " input line = " << line );
201 string start = msg.substr(begin, 1);
203 SG_LOG( SG_IO, SG_INFO, " start = " << start );
206 end = msg.find(",", begin);
207 if ( end == string::npos ) {
211 string sentence = msg.substr(begin, end - begin);
213 SG_LOG( SG_IO, SG_INFO, " sentence = " << sentence );
215 double lon_deg, lon_min, lat_deg, lat_min;
216 double lon, lat, speed, heading, altitude;
218 if ( sentence == "GPRMC" ) {
220 end = msg.find(",", begin);
221 if ( end == string::npos ) {
225 string utc = msg.substr(begin, end - begin);
227 SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
230 end = msg.find(",", begin);
231 if ( end == string::npos ) {
235 string junk = msg.substr(begin, end - begin);
237 SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
240 end = msg.find(",", begin);
241 if ( end == string::npos ) {
245 string lat_str = msg.substr(begin, end - begin);
248 lat_deg = atof( lat_str.substr(0, 2).c_str() );
249 lat_min = atof( lat_str.substr(2).c_str() );
252 end = msg.find(",", begin);
253 if ( end == string::npos ) {
257 string lat_dir = msg.substr(begin, end - begin);
260 lat = lat_deg + ( lat_min / 60.0 );
261 if ( lat_dir == "S" ) {
265 cur_fdm_state->set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
266 SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
269 end = msg.find(",", begin);
270 if ( end == string::npos ) {
274 string lon_str = msg.substr(begin, end - begin);
277 lon_deg = atof( lon_str.substr(0, 3).c_str() );
278 lon_min = atof( lon_str.substr(3).c_str() );
281 end = msg.find(",", begin);
282 if ( end == string::npos ) {
286 string lon_dir = msg.substr(begin, end - begin);
289 lon = lon_deg + ( lon_min / 60.0 );
290 if ( lon_dir == "W" ) {
294 cur_fdm_state->set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
295 SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
298 double sl_radius, lat_geoc;
299 sgGeodToGeoc( cur_fdm_state->get_Latitude(),
300 cur_fdm_state->get_Altitude(),
301 &sl_radius, &lat_geoc );
302 cur_fdm_state->set_Geocentric_Position( lat_geoc,
303 cur_fdm_state->get_Longitude(),
304 sl_radius + cur_fdm_state->get_Altitude() );
308 end = msg.find(",", begin);
309 if ( end == string::npos ) {
313 string speed_str = msg.substr(begin, end - begin);
315 speed = atof( speed_str.c_str() );
316 cur_fdm_state->set_V_calibrated_kts( speed );
317 // cur_fdm_state->set_V_ground_speed( speed );
318 SG_LOG( SG_IO, SG_INFO, " speed = " << speed );
321 end = msg.find(",", begin);
322 if ( end == string::npos ) {
326 string hdg_str = msg.substr(begin, end - begin);
328 heading = atof( hdg_str.c_str() );
329 cur_fdm_state->set_Euler_Angles( cur_fdm_state->get_Phi(),
330 cur_fdm_state->get_Theta(),
331 heading * SGD_DEGREES_TO_RADIANS );
332 SG_LOG( SG_IO, SG_INFO, " heading = " << heading );
333 } else if ( sentence == "PGRMZ" ) {
335 end = msg.find(",", begin);
336 if ( end == string::npos ) {
340 string alt_str = msg.substr(begin, end - begin);
341 altitude = atof( alt_str.c_str() );
345 end = msg.find(",", begin);
346 if ( end == string::npos ) {
350 string alt_units = msg.substr(begin, end - begin);
353 if ( alt_units != "F" && alt_units != "f" ) {
354 altitude *= SG_METER_TO_FEET;
357 cur_fdm_state->set_Altitude( altitude );
359 SG_LOG( SG_IO, SG_INFO, " altitude = " << altitude );
363 // printf("%.8f %.8f\n", lon, lat);
366 end_line = msg.find("\n", begin_line);
373 // open hailing frequencies
374 bool FGAV400::open() {
375 if ( is_enabled() ) {
376 SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
377 << "is already in use, ignoring" );
381 SGIOChannel *io = get_io_channel();
383 if ( ! io->open( get_direction() ) ) {
384 SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
394 // process work for this port
395 bool FGAV400::process() {
396 SGIOChannel *io = get_io_channel();
398 if ( get_direction() == SG_IO_OUT ) {
400 if ( ! io->write( buf, length ) ) {
401 SG_LOG( SG_IO, SG_WARN, "Error writing data." );
404 } else if ( get_direction() == SG_IO_IN ) {
405 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
406 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
407 if ( parse_message() ) {
408 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
410 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
413 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
416 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
417 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
418 if ( parse_message() ) {
419 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
421 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
424 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
434 bool FGAV400::close() {
435 SGIOChannel *io = get_io_channel();
437 set_enabled( false );
439 if ( ! io->close() ) {