gps_mod.cpp

00001 #include "mbed.h"
00002 
00003 //#ifdef GPS_
00004 
00005 #include "mbed.h"
00006 #include "gps_mod.h"
00007 using namespace std;
00008 #if defined  (TARGET_NUCLEO_L476RG)  //  Computer is low power ARM Cortex development system
00009 #include "BufferedSerial.h"
00010     BufferedSerial gps_module   (A0, A1);
00011 #endif
00012 #if defined  (TARGET_DISCO_F746NG)  //  Computer is high-end ARM Cortex development system with touch lcd
00013 #include "BufferedSoftSerial.h"
00014     BufferedSoftSerial gps_module   (A4, A5);
00015 #endif
00016 #ifdef  TARGET_NUCLEO_L432KC
00017 #include "BufferedSerial.h"
00018     extern  BufferedSerial gps_module;
00019 #endif
00020 gps_mod::gps_mod()  //  Constructor
00021 {
00022 //BufferedSoftSerial gps_module   (_pinTx : A0, _pinRx : A1);
00023     state = WAITING4DOLLAR;
00024     destptr = dest;
00025     strcpy  (latstr, "Invalid\0");
00026     strcpy  (longstr, "Invalid\0");
00027     strcpy  (altistr, "Invalid\0");
00028     strcpy  (timestr, "??:??:??\0");
00029     chcnt = 0;
00030     inmsg = false;
00031     newdata = false;
00032     posfix[0] = 'x';
00033     posfix[1] = 0;
00034     return;
00035 }
00036 
00037 bool    gps_mod::new_data()  {
00038     bool    r;
00039     r = newdata;
00040     newdata = false;
00041     return  r;    
00042 }
00043 
00044 bool    gps_mod::fix_valid()
00045 {
00046     if  (posfix[0] < '1' || posfix[0] > '3')    return  false;
00047     return  true;
00048 }
00049 
00050 char * gps_mod::date ()  {
00051     return  datestr;
00052 }
00053 
00054 char * gps_mod::heading ()   {
00055     return  headingstr;
00056 }
00057 
00058 char * gps_mod::mph ()   {
00059     return  speed_mphourstr;
00060 }
00061 
00062 char *     gps_mod::position_fix_indicator  ()
00063 {
00064     return  posfix;
00065 }
00066 
00067 char * gps_mod::latitude()
00068 {
00069     if  (fix_valid())    return  latstr;
00070     return  "No Fix ";
00071 }
00072 
00073 char * gps_mod::longitude()
00074 {
00075     if  (fix_valid())    return  longstr;
00076     return  "No Fix ";
00077 }
00078 
00079 char * gps_mod::altitude()
00080 {
00081     if  (fix_valid())    return  altistr;
00082     return  "No Fix ";
00083 }
00084 
00085 char * gps_mod::sat_count ()
00086 {
00087     return  numofsats;
00088 }
00089 
00090 char * gps_mod::message(int mess_num)
00091 {
00092     if  (mess_num < 0 || mess_num > 5)
00093         return  NULL;
00094     return  dest + mess_num * (MAXMSGLEN + 4);
00095 }
00096 
00097 char * gps_mod::time ()
00098 {
00099 //    char * t = message(0);
00100     return  timestr;
00101 }
00102 
00103 double gps_mod::lat_merged ()
00104 {
00105     double  result = strtod (latstr, NULL);
00106     return  result + (strtod (latstr + 3, NULL) / 60.0);
00107 }
00108 
00109 double gps_mod::lon_merged ()
00110 {
00111     double  result = strtod (longstr, NULL);
00112     return  result + (strtod (longstr + 4, NULL) / 60.0);
00113 }
00114 
00115 int gps_mod::update()
00116 {
00117     static const char month_tab[] = "---\0Jan\0Feb\0Mar\0Apr\0May\0Jun\0Jul\0Aug\0Sep\0Oct\0Nov\0Dec\0";
00118     const int MAX_COMMAS_IN_MSG = 24;
00119     int date, month;
00120     while   (gps_module.readable())  {
00121         ch = gps_module.getc();
00122         switch  (state) {
00123             case    WAITING4DOLLAR:
00124                 i = 0;
00125                 if  (ch == '$') state = GOTDOLLAR;
00126                 break;
00127             case    GOTDOLLAR:  //  accumulate 5 chars after '$'
00128                 hdracc[i++] = ch;
00129                 hdracc[i] = 0;
00130                 if  (i > 4) {
00131                     i = -1;
00132                     state = GOTHDR;
00133                 }
00134                 break;
00135             case    GOTHDR: //  have read "$GP???" to get here
00136 //                if  (ch != ',') pc.printf   ("Oops, comma missing\r\n");
00137                 if      (strncmp(hdracc,"GPGGA",5) == 0)  i = 0;
00138                 else if (strncmp(hdracc,"GPGLL",5) == 0)  i = 1;
00139                 else if (strncmp(hdracc,"GPGSA",5) == 0)  i = 2;
00140                 else if (strncmp(hdracc,"GPGSV",5) == 0)  i = 3;
00141                 else if (strncmp(hdracc,"GPRMC",5) == 0)  i = 4;//161229.487,A,3723.24756, N,12158.34162,W,     0.13,       309.62,  120598,,*10
00142                 //                                                  time     ?    lat            lon      ground speed knots|heading|date
00143                 else if (strncmp(hdracc,"GPVTG",5) == 0)  i = 5;
00144                 if  (i < 0) state = WAITING4DOLLAR;     //  Found invalid header info
00145                 else    {                               //  Validated header info
00146                     destptr = message(i);
00147                     chcnt = 0;
00148                     state = WAITING4CR;
00149                 }
00150                 break;
00151             case    WAITING4CR:
00152                 if  (ch == '\r')  {
00153                     state = WAITING4LF;     //  process new string data here
00154                     int comma_count = 0, comma_positions[MAX_COMMAS_IN_MSG + 2];
00155                     for (int j = 0; j < strlen(destptr) && j < MAXMSGLEN && comma_count < MAX_COMMAS_IN_MSG; j++)  {
00156                         if  (destptr[j] == ',') {
00157                             comma_positions[comma_count++] = j;
00158                             comma_positions[comma_count] = 0;
00159                         }
00160                     }
00161                     switch  (i) {
00162                         case    0:  //  GGA 183655.00,5110.25620,N,00320.09926,W,1,11,0.80,59.9,M,49.5,M,,*74
00163                             if  (comma_positions[0] == 9)    {   //  time data seems to exist
00164                                 timestr[0] = dest[0];
00165                                 timestr[1] = dest[1];
00166                                 timestr[2] = ':';
00167                                 timestr[3] = dest[2];
00168                                 timestr[4] = dest[3];
00169                                 timestr[5] = ':';
00170                                 timestr[6] = dest[4];
00171                                 timestr[7] = dest[5];
00172                                 timestr[8] = 0;
00173                             } else    {
00174                                 strcpy  (timestr, "Invalid");
00175                             }
00176                             posfix[0] = dest[comma_positions[4] + 1];
00177                             if  (fix_valid())   {
00178                                 int a = 0, b = comma_positions[5] + 1;   //  get numof sats
00179                                 if  (dest[b] == ',')    {
00180                                     numofsats[0] = '-';
00181                                     numofsats[1] = '-';
00182                                 }
00183                                 else    {
00184                                     numofsats[0] = dest[b++];
00185                                     numofsats[1] = dest[b++];
00186                                 }
00187                                 b = comma_positions[7] + 1;  //  get altitude
00188                                 char c;
00189                                 while   ((c = dest[b++]) != ',' && a < 7)
00190                                     altistr[a++] = c;
00191                                 altistr[a] = 0;
00192                             }
00193                             numofsats[2] = 0;
00194                             break;
00195                         case    1:  //  GLL 5110.25606,N,00320.10001,W,183752.00,A,A*72
00196                             latstr[0] = destptr[0];
00197                             latstr[1] = destptr[1];
00198                             latstr[2] = '~';
00199                             latstr[3] = destptr[2];
00200                             latstr[4] = destptr[3];
00201                             latstr[5] = '.';
00202                             for (int k = 5; k < 10; k++)
00203                                 latstr[k + 1] = destptr[k];
00204                             latstr[11] = ' ';
00205                             latstr[12] = destptr[11];   //  N or S
00206                             latstr[13] = 0;
00207                             for (int k = 0; k < 3; k++)
00208                                 longstr[k] = destptr[k + 13];
00209                             longstr[3] = '~';
00210                             longstr[4] = destptr[16];
00211                             longstr[5] = destptr[17];
00212                             longstr[6] = '.';
00213                             for (int k = 7; k < 12; k++)
00214                                 longstr[k] = destptr[k + 12];
00215                             longstr[12] = ' ';
00216                             longstr[13] = destptr[25];  //  E or W
00217                             longstr[14] = 0;
00218                             break;
00219                         case    2:  //  GSA A,3,11,22,01,03,17,23,19,14,09,,,,1.72,0.97,1.42*0E
00220                             break;
00221                         case    3:  //  GSV complex multiple
00222                             break;  //               0             1              2 3      4            5        67
00223                         case    4:  //  RMC 184111.00, A,5110.25663, N,00320.10076,W, 0.223,            ,  090816,,,A*6B
00224 //                                  //      161229.487,A,3723.24756, N,12158.34162,W, 0.13,       309.62,  120598,,*10
00225 //                                           time     ?    lat            lon  ground speed knots|heading|date
00226                             if  (comma_positions[6] + 1 == comma_positions[7])  //  no heading data exists
00227                                 strcpy  (headingstr, "-/-");
00228                             else
00229                                 sprintf(headingstr, "%.1f", strtod(destptr + comma_positions[6] + 1, NULL));
00230 //                            pc.printf("%s ^%s^", destptr, headingstr);
00231                             date =  (destptr[comma_positions[7] + 1] - '0') * 10 + (destptr[comma_positions[7] + 2] - '0');
00232                             month = (destptr[comma_positions[7] + 3] - '0') * 10 + (destptr[comma_positions[7] + 4] - '0');
00233                             if  (month > 12 || month < 1)
00234                                 month = 0;
00235                             month *= 4;
00236                             sprintf (datestr, "%d %s 20%d", date, &month_tab[month], strtol(&destptr[comma_positions[7] + 5], NULL, 10));
00237                             break;
00238                         case    5:  //  VTG       ,T   ,             ,M,0.098,N,0.181,K,A*2A course over ground and ground speed
00239                         //Adafruit $GPVTG,165.48,T,,M,0.03,N,0.06,K,A*37 
00240 //$                                   GPVTG 309.62,T   ,             ,M,0.13, N,0.2,  K*6E
00241                             sprintf (speed_mphourstr, "%.1fmph", km2miles * strtod(destptr + comma_positions[5] + 1, NULL));
00242                             newdata = true;
00243                             break;  //      course true|course magnetic|knots|km/hour
00244                         default:
00245 //                            pc.printf   ("Naf i = %d\r\n", i);
00246                             break;
00247                     }
00248                 } else    { //  char is not CR
00249                     if  (chcnt > MAXMSGLEN)    chcnt = MAXMSGLEN;
00250                     destptr[chcnt++] = ch;
00251                     destptr[chcnt] = 0;
00252                 }
00253                 break;
00254             case    WAITING4LF:
00255 //                if  (ch != '\n')
00256 //                    pc.printf   ("Oops, no LF\r\n");
00257                 state = WAITING4DOLLAR;
00258                 break;
00259             default:
00260                 break;
00261         }
00262     }
00263     return 0;
00264 }   //      end of int gps_mod::update()
00265 
00266 //#endif