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.
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 <Main/fg_props.hxx>
36 #include <Main/globals.hxx>
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);
69 // generate AV400 message
70 bool FGAV400::gen_message() {
71 // cout << "generating garmin message" << endl;
73 char msg_z[32], msg_A[32], msg_B[32], msg_C[32], msg_D[32];
74 char msg_Q[32], msg_T[32], msg_type2[256];
75 // the following could be implemented, but currently are unused
76 // char msg_E[32], msg_G[32], msg_I[32], msg_K[32], msg_L[32], msg_S[32];
84 sprintf( msg_z, "z%05.0f\r\n", fdm.get_Altitude() );
89 double latd = fdm.get_Latitude() * SGD_RADIANS_TO_DEGREES;
97 min = (latd - (double)deg) * 60.0 * 100.0;
98 sprintf( msg_A, "A%c %02d %04.0f\r\n", dir, deg, min);
101 double lond = fdm.get_Longitude() * SGD_RADIANS_TO_DEGREES;
109 min = (lond - (double)deg) * 60.0 * 100.0;
110 sprintf( msg_B, "B%c %03d %04.0f\r\n", dir, deg, min);
113 float magdeg = fgGetDouble( "/environment/magnetic-variation-deg" );
114 double vn = fgGetDouble( "/velocities/speed-north-fps" );
115 double ve = fgGetDouble( "/velocities/speed-east-fps" );
116 double gnd_trk_true = atan2( ve, vn ) * SGD_RADIANS_TO_DEGREES;
117 double gnd_trk_mag = gnd_trk_true - magdeg;
118 if ( gnd_trk_mag < 0.0 ) { gnd_trk_mag += 360.0; }
119 if ( gnd_trk_mag >= 360.0 ) { gnd_trk_mag -= 360.0; }
120 sprintf( msg_C, "C%03.0f\r\n", gnd_trk_mag);
123 double speed_kt = sqrt( vn*vn + ve*ve ) * SG_FPS_TO_KT;
124 if ( speed_kt > 999.0 ) {
127 sprintf( msg_D, "D%03.0f\r\n", speed_kt);
129 // create msg_E (not implemented)
130 // create msg_G (not implemented)
131 // create msg_I (not implemented)
132 // create msg_K (not implemented)
133 // create msg_L (not implemented)
136 if ( magdeg < 0.0 ) {
142 sprintf( msg_Q, "Q%c%03.0f\r\n", dir, magdeg * 10.0 );
144 // create msg_S (not implemented)
147 sprintf( msg_T, "T---------\r\n" );
149 // create msg_l (not implemented)
152 sprintf( msg_type2, "w01%c\r\n", (char)65 );
156 sentence += '\002'; // STX
157 sentence += msg_z; // altitude
158 sentence += msg_A; // latitude
159 sentence += msg_B; // longitude
160 sentence += msg_C; // ground track
161 sentence += msg_D; // ground speed (kt)
162 // sentence += "E-----\r\n";
163 // sentence += "G-----\r\n";
164 // sentence += "I----\r\n";
165 // sentence += "K-----\r\n";
166 // sentence += "L----\r\n";
167 sentence += msg_Q; // magvar
168 // sentence += "S-----\r\n";
169 sentence += msg_T; // end of type 1 messages (must be sent)
170 sentence += msg_type2; // type2 message
171 // sentence += "l------\r\n";
172 sentence += '\003'; // ETX
175 length = sentence.length();
176 // cout << endl << "length = " << length << endl;
177 strncpy( buf, sentence.c_str(), length );
183 // parse AV400 message
184 bool FGAV400::parse_message() {
185 SG_LOG( SG_IO, SG_INFO, "parse garmin message" );
188 msg = msg.substr( 0, length );
189 SG_LOG( SG_IO, SG_INFO, "entire message = " << msg );
191 string::size_type begin_line, end_line, begin, end;
192 begin_line = begin = 0;
194 // extract out each line
195 end_line = msg.find("\n", begin_line);
196 while ( end_line != string::npos ) {
197 string line = msg.substr(begin_line, end_line - begin_line);
198 begin_line = end_line + 1;
199 SG_LOG( SG_IO, SG_INFO, " input line = " << line );
202 string start = msg.substr(begin, 1);
204 SG_LOG( SG_IO, SG_INFO, " start = " << start );
207 end = msg.find(",", begin);
208 if ( end == string::npos ) {
212 string sentence = msg.substr(begin, end - begin);
214 SG_LOG( SG_IO, SG_INFO, " sentence = " << sentence );
216 double lon_deg, lon_min, lat_deg, lat_min;
217 double lon, lat, speed, heading, altitude;
219 if ( sentence == "GPRMC" ) {
221 end = msg.find(",", begin);
222 if ( end == string::npos ) {
226 string utc = msg.substr(begin, end - begin);
228 SG_LOG( SG_IO, SG_INFO, " utc = " << utc );
231 end = msg.find(",", begin);
232 if ( end == string::npos ) {
236 string junk = msg.substr(begin, end - begin);
238 SG_LOG( SG_IO, SG_INFO, " junk = " << junk );
241 end = msg.find(",", begin);
242 if ( end == string::npos ) {
246 string lat_str = msg.substr(begin, end - begin);
249 lat_deg = atof( lat_str.substr(0, 2).c_str() );
250 lat_min = atof( lat_str.substr(2).c_str() );
253 end = msg.find(",", begin);
254 if ( end == string::npos ) {
258 string lat_dir = msg.substr(begin, end - begin);
261 lat = lat_deg + ( lat_min / 60.0 );
262 if ( lat_dir == "S" ) {
266 fdm.set_Latitude( lat * SGD_DEGREES_TO_RADIANS );
267 SG_LOG( SG_IO, SG_INFO, " lat = " << lat );
270 end = msg.find(",", begin);
271 if ( end == string::npos ) {
275 string lon_str = msg.substr(begin, end - begin);
278 lon_deg = atof( lon_str.substr(0, 3).c_str() );
279 lon_min = atof( lon_str.substr(3).c_str() );
282 end = msg.find(",", begin);
283 if ( end == string::npos ) {
287 string lon_dir = msg.substr(begin, end - begin);
290 lon = lon_deg + ( lon_min / 60.0 );
291 if ( lon_dir == "W" ) {
295 fdm.set_Longitude( lon * SGD_DEGREES_TO_RADIANS );
296 SG_LOG( SG_IO, SG_INFO, " lon = " << lon );
299 double sl_radius, lat_geoc;
300 sgGeodToGeoc( fdm.get_Latitude(),
302 &sl_radius, &lat_geoc );
303 fdm.set_Geocentric_Position( lat_geoc,
305 sl_radius + fdm.get_Altitude() );
309 end = msg.find(",", begin);
310 if ( end == string::npos ) {
314 string speed_str = msg.substr(begin, end - begin);
316 speed = atof( speed_str.c_str() );
317 fdm.set_V_calibrated_kts( speed );
318 // fdm.set_V_ground_speed( speed );
319 SG_LOG( SG_IO, SG_INFO, " speed = " << speed );
322 end = msg.find(",", begin);
323 if ( end == string::npos ) {
327 string hdg_str = msg.substr(begin, end - begin);
329 heading = atof( hdg_str.c_str() );
330 fdm.set_Euler_Angles( fdm.get_Phi(),
332 heading * SGD_DEGREES_TO_RADIANS );
333 SG_LOG( SG_IO, SG_INFO, " heading = " << heading );
334 } else if ( sentence == "PGRMZ" ) {
336 end = msg.find(",", begin);
337 if ( end == string::npos ) {
341 string alt_str = msg.substr(begin, end - begin);
342 altitude = atof( alt_str.c_str() );
346 end = msg.find(",", begin);
347 if ( end == string::npos ) {
351 string alt_units = msg.substr(begin, end - begin);
354 if ( alt_units != "F" && alt_units != "f" ) {
355 altitude *= SG_METER_TO_FEET;
358 fdm.set_Altitude( altitude );
360 SG_LOG( SG_IO, SG_INFO, " altitude = " << altitude );
364 // printf("%.8f %.8f\n", lon, lat);
367 end_line = msg.find("\n", begin_line);
374 // open hailing frequencies
375 bool FGAV400::open() {
376 if ( is_enabled() ) {
377 SG_LOG( SG_IO, SG_ALERT, "This shouldn't happen, but the channel "
378 << "is already in use, ignoring" );
382 SGIOChannel *io = get_io_channel();
384 if ( ! io->open( get_direction() ) ) {
385 SG_LOG( SG_IO, SG_ALERT, "Error opening channel communication layer." );
395 // process work for this port
396 bool FGAV400::process() {
397 SGIOChannel *io = get_io_channel();
399 if ( get_direction() == SG_IO_OUT ) {
401 if ( ! io->write( buf, length ) ) {
402 SG_LOG( SG_IO, SG_WARN, "Error writing data." );
405 } else if ( get_direction() == SG_IO_IN ) {
406 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
407 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
408 if ( parse_message() ) {
409 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
411 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
414 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
417 if ( (length = io->readline( buf, FG_MAX_MSG_SIZE )) > 0 ) {
418 SG_LOG( SG_IO, SG_ALERT, "Success reading data." );
419 if ( parse_message() ) {
420 SG_LOG( SG_IO, SG_ALERT, "Success parsing data." );
422 SG_LOG( SG_IO, SG_ALERT, "Error parsing data." );
425 SG_LOG( SG_IO, SG_ALERT, "Error reading data." );
435 bool FGAV400::close() {
436 SGIOChannel *io = get_io_channel();
438 set_enabled( false );
440 if ( ! io->close() ) {