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 <Main/fg_props.hxx>
34 #include <Main/globals.hxx>
46 // calculate the garmin check sum
47 static char calc_nmea_cksum(char *sentence) {
48 unsigned char sum = 0;
51 // cout << sentence << endl;
53 len = strlen(sentence);
55 for ( i = 1; i < len; i++ ) {
56 // cout << sentence[i];
61 // printf("sum = %02x\n", sum);
67 // generate AV400 message
68 bool FGAV400::gen_message() {
69 // cout << "generating garmin message" << endl;
71 char msg_z[32], msg_A[32], msg_B[32], msg_C[32], msg_D[32];
72 char msg_Q[32], msg_T[32], msg_type2[256];
73 // the following could be implemented, but currently are unused
74 // char msg_E[32], msg_G[32], msg_I[32], msg_K[32], msg_L[32], msg_S[32];
82 sprintf( msg_z, "z%05.0f\r\n", fdm.get_Altitude() );
87 double latd = fdm.get_Latitude() * SGD_RADIANS_TO_DEGREES;
95 min = (latd - (double)deg) * 60.0 * 100.0;
96 sprintf( msg_A, "A%c %02d %04.0f\r\n", dir, deg, min);
99 double lond = fdm.get_Longitude() * SGD_RADIANS_TO_DEGREES;
107 min = (lond - (double)deg) * 60.0 * 100.0;
108 sprintf( msg_B, "B%c %03d %04.0f\r\n", dir, deg, min);
111 float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
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 double gnd_trk_mag = gnd_trk_true - magdeg;
116 if ( gnd_trk_mag < 0.0 ) { gnd_trk_mag += 360.0; }
117 if ( gnd_trk_mag >= 360.0 ) { gnd_trk_mag -= 360.0; }
118 sprintf( msg_C, "C%03.0f\r\n", gnd_trk_mag);
121 double speed_kt = sqrt( vn*vn + ve*ve ) * SG_FPS_TO_KT;
122 if ( speed_kt > 999.0 ) {
125 sprintf( msg_D, "D%03.0f\r\n", speed_kt);
127 // create msg_E (not implemented)
128 // create msg_G (not implemented)
129 // create msg_I (not implemented)
130 // create msg_K (not implemented)
131 // create msg_L (not implemented)
134 if ( magdeg < 0.0 ) {
140 sprintf( msg_Q, "Q%c%03.0f\r\n", dir, magdeg * 10.0 );
142 // create msg_S (not implemented)
145 sprintf( msg_T, "T---------\r\n" );
147 // create msg_l (not implemented)
150 sprintf( msg_type2, "w01%c\r\n", (char)65 );
154 sentence += '\002'; // STX
155 sentence += msg_z; // altitude
156 sentence += msg_A; // latitude
157 sentence += msg_B; // longitude
158 sentence += msg_C; // ground track
159 sentence += msg_D; // ground speed (kt)
160 // sentence += "E-----\r\n";
161 // sentence += "G-----\r\n";
162 // sentence += "I----\r\n";
163 // sentence += "K-----\r\n";
164 // sentence += "L----\r\n";
165 sentence += msg_Q; // magvar
166 // sentence += "S-----\r\n";
167 sentence += msg_T; // end of type 1 messages (must be sent)
168 sentence += msg_type2; // type2 message
169 // sentence += "l------\r\n";
170 sentence += '\003'; // ETX
173 length = sentence.length();
174 // cout << endl << "length = " << length << endl;
175 strncpy( buf, sentence.c_str(), length );
181 // parse AV400 message
182 bool FGAV400::parse_message() {
183 SG_LOG( SG_IO, SG_INFO, "parse garmin message" );
186 msg = msg.substr( 0, length );
187 SG_LOG( SG_IO, SG_INFO, "entire message = " << msg );
189 string::size_type begin_line, end_line, begin, end;
190 begin_line = begin = 0;
192 // extract out each line
193 end_line = msg.find("\n", begin_line);
194 while ( end_line != string::npos ) {
195 string line = msg.substr(begin_line, end_line - begin_line);
196 begin_line = end_line + 1;
197 SG_LOG( SG_IO, SG_INFO, " input line = " << line );
200 string start = msg.substr(begin, 1);
202 SG_LOG( SG_IO, SG_INFO, " start = " << start );
205 end = msg.find(",", begin);
206 if ( end == string::npos ) {
210 string sentence = msg.substr(begin, end - begin);
212 SG_LOG( SG_IO, SG_INFO, " sentence = " << sentence );
214 double lon_deg, lon_min, lat_deg, lat_min;
215 double lon, lat, speed, heading, altitude;
217 if ( sentence == "GPRMC" ) {
219 end = msg.find(",", begin);
220 if ( end == string::npos ) {
224 string utc = msg.substr(begin, end - begin);
226 SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
229 end = msg.find(",", begin);
230 if ( end == string::npos ) {
234 string junk = msg.substr(begin, end - begin);
236 SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
239 end = msg.find(",", begin);
240 if ( end == string::npos ) {
244 string lat_str = msg.substr(begin, end - begin);
247 lat_deg = atof( lat_str.substr(0, 2).c_str() );
248 lat_min = atof( lat_str.substr(2).c_str() );
251 end = msg.find(",", begin);
252 if ( end == string::npos ) {
256 string lat_dir = msg.substr(begin, end - begin);
259 lat = lat_deg + ( lat_min / 60.0 );
260 if ( lat_dir == "S" ) {
264 fdm.set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
265 SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
268 end = msg.find(",", begin);
269 if ( end == string::npos ) {
273 string lon_str = msg.substr(begin, end - begin);
276 lon_deg = atof( lon_str.substr(0, 3).c_str() );
277 lon_min = atof( lon_str.substr(3).c_str() );
280 end = msg.find(",", begin);
281 if ( end == string::npos ) {
285 string lon_dir = msg.substr(begin, end - begin);
288 lon = lon_deg + ( lon_min / 60.0 );
289 if ( lon_dir == "W" ) {
293 fdm.set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
294 SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
297 double sl_radius, lat_geoc;
298 sgGeodToGeoc( fdm.get_Latitude(),
300 &sl_radius, &lat_geoc );
301 fdm.set_Geocentric_Position( lat_geoc,
303 sl_radius + fdm.get_Altitude() );
307 end = msg.find(",", begin);
308 if ( end == string::npos ) {
312 string speed_str = msg.substr(begin, end - begin);
314 speed = atof( speed_str.c_str() );
315 fdm.set_V_calibrated_kts( speed );
316 // fdm.set_V_ground_speed( speed );
317 SG_LOG( SG_IO, SG_INFO, " speed = " << speed );
320 end = msg.find(",", begin);
321 if ( end == string::npos ) {
325 string hdg_str = msg.substr(begin, end - begin);
327 heading = atof( hdg_str.c_str() );
328 fdm.set_Euler_Angles( fdm.get_Phi(),
330 heading * SGD_DEGREES_TO_RADIANS );
331 SG_LOG( SG_IO, SG_INFO, " heading = " << heading );
332 } else if ( sentence == "PGRMZ" ) {
334 end = msg.find(",", begin);
335 if ( end == string::npos ) {
339 string alt_str = msg.substr(begin, end - begin);
340 altitude = atof( alt_str.c_str() );
344 end = msg.find(",", begin);
345 if ( end == string::npos ) {
349 string alt_units = msg.substr(begin, end - begin);
352 if ( alt_units != "F" && alt_units != "f" ) {
353 altitude *= SG_METER_TO_FEET;
356 fdm.set_Altitude( altitude );
358 SG_LOG( SG_IO, SG_INFO, " altitude = " << altitude );
362 // printf("%.8f %.8f\n", lon, lat);
365 end_line = msg.find("\n", begin_line);
372 // open hailing frequencies
373 bool FGAV400::open() {
374 if ( is_enabled() ) {
375 SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
376 << "is already in use, ignoring" );
380 SGIOChannel *io = get_io_channel();
382 if ( ! io->open( get_direction() ) ) {
383 SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
393 // process work for this port
394 bool FGAV400::process() {
395 SGIOChannel *io = get_io_channel();
397 if ( get_direction() == SG_IO_OUT ) {
399 if ( ! io->write( buf, length ) ) {
400 SG_LOG( SG_IO, SG_WARN, "Error writing data." );
403 } else if ( get_direction() == SG_IO_IN ) {
404 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
405 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
406 if ( parse_message() ) {
407 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
409 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
412 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
415 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
416 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
417 if ( parse_message() ) {
418 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
420 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
423 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
433 bool FGAV400::close() {
434 SGIOChannel *io = get_io_channel();
436 set_enabled( false );
438 if ( ! io->close() ) {