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   1 /*
   2  * Copyright © 2009 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #ifndef AO_GPS_TEST
  19 #include "ao.h"
  20 #endif
  21
  22 #define AO_GPS_LEADER           2
  23
  24 static const char ao_gps_header[] = "GP";
  25
  26 __xdata uint8_t ao_gps_mutex;
  27 static __xdata char ao_gps_char;
  28 static __xdata uint8_t ao_gps_cksum;
  29 static __xdata uint8_t ao_gps_error;
  30
  31 __xdata uint16_t ao_gps_tick;
  32 __xdata struct ao_gps_data      ao_gps_data;
  33 __xdata struct ao_gps_tracking_data     ao_gps_tracking_data;
  34
  35 static __xdata uint16_t                         ao_gps_next_tick;
  36 static __xdata struct ao_gps_data               ao_gps_next;
  37 static __xdata uint8_t                          ao_gps_date_flags;
  38 static __xdata struct ao_gps_tracking_data      ao_gps_tracking_next;
  39
  40 static const char ao_gps_config[] = {
  41         0xa0, 0xa1, 0x00, 0x09,         /* length 9 bytes */
  42         0x08,                           /* configure nmea */
  43         1,                              /* gga interval */
  44         1,                              /* gsa interval */
  45         1,                              /* gsv interval */
  46         1,                              /* gll interval */
  47         1,                              /* rmc interval */
  48         1,                              /* vtg interval */
  49         1,                              /* zda interval */
  50         0,                              /* attributes (0 = update to sram, 1 = update flash too) */
  51         0x09, 0x0d, 0x0a,
  52
  53         0xa0, 0xa1, 0x00, 0x03,         /* length: 3 bytes */
  54         0x3c,                           /* configure navigation mode */
  55         0x00,                           /* 0 = car, 1 = pedestrian */
  56         0x00,                           /* 0 = update to sram, 1 = update sram + flash */
  57         0x3c, 0x0d, 0x0a,
  58 };
  59
  60 static void
  61 ao_gps_lexchar(void)
  62 {
  63         if (ao_gps_error)
  64                 ao_gps_char = '\n';
  65         else
  66                 ao_gps_char = ao_serial_getchar();
  67         ao_gps_cksum ^= ao_gps_char;
  68 }
  69
  70 void
  71 ao_gps_skip(void)
  72 {
  73         while (ao_gps_char >= '0')
  74                 ao_gps_lexchar();
  75 }
  76
  77 void
  78 ao_gps_skip_field(void)
  79 {
  80         while (ao_gps_char != ',' && ao_gps_char != '*' && ao_gps_char != '\n')
  81                 ao_gps_lexchar();
  82 }
  83
  84 void
  85 ao_gps_skip_sep(void)
  86 {
  87         if (ao_gps_char == ',' || ao_gps_char == '.' || ao_gps_char == '*')
  88                 ao_gps_lexchar();
  89 }
  90
  91 __xdata static uint8_t ao_gps_num_width;
  92
  93 static int16_t
  94 ao_gps_decimal(uint8_t max_width)
  95 {
  96         int16_t v;
  97         __xdata uint8_t neg = 0;
  98
  99         ao_gps_skip_sep();
 100         if (ao_gps_char == '-') {
 101                 neg = 1;
 102                 ao_gps_lexchar();
 103         }
 104         v = 0;
 105         ao_gps_num_width = 0;
 106         while (ao_gps_num_width < max_width) {
 107                 if (ao_gps_char < '0' || '9' < ao_gps_char)
 108                         break;
 109                 v = v * (int16_t) 10 + ao_gps_char - '0';
 110                 ao_gps_num_width++;
 111                 ao_gps_lexchar();
 112         }
 113         if (neg)
 114                 v = -v;
 115         return v;
 116 }
 117
 118 static uint8_t
 119 ao_gps_hex(uint8_t max_width)
 120 {
 121         uint8_t v, d;
 122
 123         ao_gps_skip_sep();
 124         v = 0;
 125         ao_gps_num_width = 0;
 126         while (ao_gps_num_width < max_width) {
 127                 if ('0' <= ao_gps_char && ao_gps_char <= '9')
 128                         d = ao_gps_char - '0';
 129                 else if ('A' <= ao_gps_char && ao_gps_char <= 'F')
 130                         d = ao_gps_char - 'A' + 10;
 131                 else if ('a' <= ao_gps_char && ao_gps_char <= 'f')
 132                         d = ao_gps_char - 'a' + 10;
 133                 else
 134                         break;
 135                 v = (v << 4) | d;
 136                 ao_gps_num_width++;
 137                 ao_gps_lexchar();
 138         }
 139         return v;
 140 }
 141
 142 static int32_t
 143 ao_gps_parse_pos(uint8_t deg_width) __reentrant
 144 {
 145         int32_t d;
 146         int32_t m;
 147         int32_t f;
 148
 149         d = ao_gps_decimal(deg_width);
 150         m = ao_gps_decimal(2);
 151         if (ao_gps_char == '.') {
 152                 f = ao_gps_decimal(4);
 153                 while (ao_gps_num_width < 4) {
 154                         f *= 10;
 155                         ao_gps_num_width++;
 156                 }
 157         } else {
 158                 f = 0;
 159                 if (ao_gps_char != ',')
 160                         ao_gps_error = 1;
 161         }
 162         d = d * 10000000l;
 163         m = m * 10000l + f;
 164         d = d + m * 50 / 3;
 165         return d;
 166 }
 167
 168 static uint8_t
 169 ao_gps_parse_flag(char no_c, char yes_c) __reentrant
 170 {
 171         uint8_t ret = 0;
 172         ao_gps_skip_sep();
 173         if (ao_gps_char == yes_c)
 174                 ret = 1;
 175         else if (ao_gps_char == no_c)
 176                 ret = 0;
 177         else
 178                 ao_gps_error = 1;
 179         ao_gps_lexchar();
 180         return ret;
 181 }
 182
 183
 184 void
 185 ao_gps(void) __reentrant
 186 {
 187         char    a, c;
 188         uint8_t i;
 189
 190         ao_serial_set_speed(AO_SERIAL_SPEED_9600);
 191         for (i = 0; i < sizeof (ao_gps_config); i++)
 192                 ao_serial_putchar(ao_gps_config[i]);
 193         for (;;) {
 194                 /* Locate the begining of the next record */
 195                 for (;;) {
 196                         c = ao_serial_getchar();
 197                         if (c == '$')
 198                                 break;
 199                 }
 200
 201                 ao_gps_cksum = 0;
 202                 ao_gps_error = 0;
 203
 204                 /* Skip anything other than GP */
 205                 for (i = 0; i < AO_GPS_LEADER; i++) {
 206                         ao_gps_lexchar();
 207                         if (ao_gps_char != ao_gps_header[i])
 208                                 break;
 209                 }
 210                 if (i != AO_GPS_LEADER)
 211                         continue;
 212
 213                 /* pull the record identifier characters off the link */
 214                 ao_gps_lexchar();
 215                 a = ao_gps_char;
 216                 ao_gps_lexchar();
 217                 c = ao_gps_char;
 218                 ao_gps_lexchar();
 219                 i = ao_gps_char;
 220                 ao_gps_lexchar();
 221                 if (ao_gps_char != ',')
 222                         continue;
 223
 224                 if (a == (uint8_t) 'G' && c == (uint8_t) 'G' && i == (uint8_t) 'A') {
 225                         /* Now read the data into the gps data record
 226                          *
 227                          * $GPGGA,025149.000,4528.1723,N,12244.2480,W,1,05,2.0,103.5,M,-19.5,M,,0000*66
 228                          *
 229                          * Essential fix data
 230                          *
 231                          *         025149.000   time (02:51:49.000 GMT)
 232                          *         4528.1723,N  Latitude 45°28.1723' N
 233                          *         12244.2480,W Longitude 122°44.2480' W
 234                          *         1            Fix quality:
 235                          *                                 0 = invalid
 236                          *                                 1 = GPS fix (SPS)
 237                          *                                 2 = DGPS fix
 238                          *                                 3 = PPS fix
 239                          *                                 4 = Real Time Kinematic
 240                          *                                 5 = Float RTK
 241                          *                                 6 = estimated (dead reckoning)
 242                          *                                 7 = Manual input mode
 243                          *                                 8 = Simulation mode
 244                          *         05           Number of satellites (5)
 245                          *         2.0          Horizontal dilution
 246                          *         103.5,M              Altitude, 103.5M above msl
 247                          *         -19.5,M              Height of geoid above WGS84 ellipsoid
 248                          *         ?            time in seconds since last DGPS update
 249                          *         0000         DGPS station ID
 250                          *         *66          checksum
 251                          */
 252
 253                         ao_gps_next_tick = ao_time();
 254                         ao_gps_next.flags = AO_GPS_RUNNING | ao_gps_date_flags;
 255                         ao_gps_next.hour = ao_gps_decimal(2);
 256                         ao_gps_next.minute = ao_gps_decimal(2);
 257                         ao_gps_next.second = ao_gps_decimal(2);
 258                         ao_gps_skip_field();    /* skip seconds fraction */
 259
 260                         ao_gps_next.latitude = ao_gps_parse_pos(2);
 261                         if (ao_gps_parse_flag('N', 'S'))
 262                                 ao_gps_next.latitude = -ao_gps_next.latitude;
 263                         ao_gps_next.longitude = ao_gps_parse_pos(3);
 264                         if (ao_gps_parse_flag('E', 'W'))
 265                                 ao_gps_next.longitude = -ao_gps_next.longitude;
 266
 267                         i = ao_gps_decimal(0xff);
 268                         if (i == 1)
 269                                 ao_gps_next.flags |= AO_GPS_VALID;
 270
 271                         i = ao_gps_decimal(0xff) << AO_GPS_NUM_SAT_SHIFT;
 272                         if (i > AO_GPS_NUM_SAT_MASK)
 273                                 i = AO_GPS_NUM_SAT_MASK;
 274                         ao_gps_next.flags |= i;
 275
 276                         ao_gps_lexchar();
 277                         ao_gps_next.hdop = ao_gps_decimal(0xff);
 278                         if (ao_gps_next.hdop <= 50) {
 279                                 ao_gps_next.hdop = (uint8_t) 5 * ao_gps_next.hdop;
 280                                 if (ao_gps_char == '.')
 281                                         ao_gps_next.hdop = (ao_gps_next.hdop +
 282                                                             ((uint8_t) ao_gps_decimal(1) >> 1));
 283                         } else
 284                                 ao_gps_next.hdop = 255;
 285                         ao_gps_skip_field();
 286
 287                         ao_gps_next.altitude = ao_gps_decimal(0xff);
 288                         ao_gps_skip_field();    /* skip any fractional portion */
 289
 290                         /* Skip remaining fields */
 291                         while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
 292                                 ao_gps_lexchar();
 293                                 ao_gps_skip_field();
 294                         }
 295                         if (ao_gps_char == '*') {
 296                                 uint8_t cksum = ao_gps_cksum ^ '*';
 297                                 if (cksum != ao_gps_hex(2))
 298                                         ao_gps_error = 1;
 299                         } else
 300                                 ao_gps_error = 1;
 301                         if (!ao_gps_error) {
 302                                 ao_mutex_get(&ao_gps_mutex);
 303                                 ao_gps_tick = ao_gps_next_tick;
 304                                 memcpy(&ao_gps_data, &ao_gps_next, sizeof (struct ao_gps_data));
 305                                 ao_mutex_put(&ao_gps_mutex);
 306                                 ao_wakeup(&ao_gps_data);
 307                         }
 308                 } else if (a == (uint8_t) 'G' && c == (uint8_t) 'S' && i == (uint8_t) 'V') {
 309                         uint8_t done;
 310                         /* Now read the data into the GPS tracking data record
 311                          *
 312                          * $GPGSV,3,1,12,05,54,069,45,12,44,061,44,21,07,184,46,22,78,289,47*72<CR><LF>
 313                          *
 314                          * Satellites in view data
 315                          *
 316                          *      3               Total number of GSV messages
 317                          *      1               Sequence number of current GSV message
 318                          *      12              Total sats in view (0-12)
 319                          *      05              SVID
 320                          *      54              Elevation
 321                          *      069             Azimuth
 322                          *      45              C/N0 in dB
 323                          *      ...             other SVIDs
 324                          *      72              checksum
 325                          */
 326                         c = ao_gps_decimal(1);  /* total messages */
 327                         i = ao_gps_decimal(1);  /* message sequence */
 328                         if (i == 1) {
 329                                 ao_gps_tracking_next.channels = 0;
 330                         }
 331                         done = (uint8_t) c == i;
 332                         ao_gps_lexchar();
 333                         ao_gps_skip_field();    /* sats in view */
 334                         while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
 335                                 i = ao_gps_tracking_next.channels;
 336                                 c = ao_gps_decimal(2);  /* SVID */
 337                                 if (i < AO_MAX_GPS_TRACKING)
 338                                         ao_gps_tracking_next.sats[i].svid = c;
 339                                 ao_gps_lexchar();
 340                                 ao_gps_skip_field();    /* elevation */
 341                                 ao_gps_lexchar();
 342                                 ao_gps_skip_field();    /* azimuth */
 343                                 c = ao_gps_decimal(2);  /* C/N0 */
 344                                 if (i < AO_MAX_GPS_TRACKING) {
 345                                         if (!(ao_gps_tracking_next.sats[i].c_n_1 = c))
 346                                                 ao_gps_tracking_next.sats[i].svid = 0;
 347                                         ao_gps_tracking_next.channels = i + 1;
 348                                 }
 349                         }
 350                         if (ao_gps_char == '*') {
 351                                 uint8_t cksum = ao_gps_cksum ^ '*';
 352                                 if (cksum != ao_gps_hex(2))
 353                                         ao_gps_error = 1;
 354                         }
 355                         else
 356                                 ao_gps_error = 1;
 357                         if (ao_gps_error)
 358                                 ao_gps_tracking_next.channels = 0;
 359                         else if (done) {
 360                                 ao_mutex_get(&ao_gps_mutex);
 361                                 memcpy(&ao_gps_tracking_data, &ao_gps_tracking_next,
 362                                        sizeof(ao_gps_tracking_data));
 363                                 ao_mutex_put(&ao_gps_mutex);
 364                                 ao_wakeup(&ao_gps_tracking_data);
 365                         }
 366                 } else if (a == (uint8_t) 'R' && c == (uint8_t) 'M' && i == (uint8_t) 'C') {
 367                         /* Parse the RMC record to read out the current date */
 368
 369                         /* $GPRMC,111636.932,A,2447.0949,N,12100.5223,E,000.0,000.0,030407,,,A*61
 370                          *
 371                          * Recommended Minimum Specific GNSS Data
 372                          *
 373                          *      111636.932      UTC time 11:16:36.932
 374                          *      A               Data Valid (V = receiver warning)
 375                          *      2447.0949       Latitude
 376                          *      N               North/south indicator
 377                          *      12100.5223      Longitude
 378                          *      E               East/west indicator
 379                          *      000.0           Speed over ground
 380                          *      000.0           Course over ground
 381                          *      030407          UTC date (ddmmyy format)
 382                          *      A               Mode indicator:
 383                          *                      N = data not valid
 384                          *                      A = autonomous mode
 385                          *                      D = differential mode
 386                          *                      E = estimated (dead reckoning) mode
 387                          *                      M = manual input mode
 388                          *                      S = simulator mode
 389                          *      61              checksum
 390                          */
 391                         ao_gps_skip_field();
 392                         for (i = 0; i < 8; i++) {
 393                                 ao_gps_lexchar();
 394                                 ao_gps_skip_field();
 395                         }
 396                         a = ao_gps_decimal(2);
 397                         c = ao_gps_decimal(2);
 398                         i = ao_gps_decimal(2);
 399                         /* Skip remaining fields */
 400                         while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
 401                                 ao_gps_lexchar();
 402                                 ao_gps_skip_field();
 403                         }
 404                         if (ao_gps_char == '*') {
 405                                 uint8_t cksum = ao_gps_cksum ^ '*';
 406                                 if (cksum != ao_gps_hex(2))
 407                                         ao_gps_error = 1;
 408                         } else
 409                                 ao_gps_error = 1;
 410                         if (!ao_gps_error) {
 411                                 ao_gps_next.year = i;
 412                                 ao_gps_next.month = c;
 413                                 ao_gps_next.day = a;
 414                                 ao_gps_date_flags = AO_GPS_DATE_VALID;
 415                         }
 416                 }
 417         }
 418 }
 419
 420 __xdata struct ao_task ao_gps_task;
 421
 422 static void
 423 gps_dump(void) __reentrant
 424 {
 425         ao_mutex_get(&ao_gps_mutex);
 426         printf ("Date: %02d/%02d/%02d\n", ao_gps_data.year, ao_gps_data.month, ao_gps_data.day);
 427         printf ("Time: %02d:%02d:%02d\n", ao_gps_data.hour, ao_gps_data.minute, ao_gps_data.second);
 428         printf ("Lat/Lon: %ld %ld\n", ao_gps_data.latitude, ao_gps_data.longitude);
 429         printf ("Alt: %d\n", ao_gps_data.altitude);
 430         printf ("Flags: 0x%x\n", ao_gps_data.flags);
 431         ao_mutex_put(&ao_gps_mutex);
 432 }
 433
 434 __code struct ao_cmds ao_gps_cmds[] = {
 435         { 'g', gps_dump,        "g                                  Display current GPS values" },
 436         { 0,   gps_dump, NULL },
 437 };
 438
 439 void
 440 ao_gps_init(void)
 441 {
 442         ao_add_task(&ao_gps_task, ao_gps, "gps");
 443         ao_cmd_register(&ao_gps_cmds[0]);
 444 }