nmea gps library - without any serial
Fork of GPS by
GPS_parser.cpp@5:94daced1e61a, 2012-12-12 (annotated)
- Committer:
- tylerjw
- Date:
- Wed Dec 12 17:32:31 2012 +0000
- Revision:
- 5:94daced1e61a
- Child:
- 6:4ed12067a314
bug fix
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
tylerjw | 5:94daced1e61a | 1 | #include "GPS_parser.h" |
tylerjw | 5:94daced1e61a | 2 | |
tylerjw | 5:94daced1e61a | 3 | GPS_Parser::GPS_Parser() |
tylerjw | 5:94daced1e61a | 4 | { |
tylerjw | 5:94daced1e61a | 5 | nmea_longitude = 0.0; |
tylerjw | 5:94daced1e61a | 6 | nmea_latitude = 0.0; |
tylerjw | 5:94daced1e61a | 7 | utc_time = 0; |
tylerjw | 5:94daced1e61a | 8 | ns = ' '; |
tylerjw | 5:94daced1e61a | 9 | ew = ' '; |
tylerjw | 5:94daced1e61a | 10 | lock = 0; |
tylerjw | 5:94daced1e61a | 11 | satelites = 0; |
tylerjw | 5:94daced1e61a | 12 | hdop = 0.0; |
tylerjw | 5:94daced1e61a | 13 | msl_altitude = 0.0; |
tylerjw | 5:94daced1e61a | 14 | msl_units = ' '; |
tylerjw | 5:94daced1e61a | 15 | |
tylerjw | 5:94daced1e61a | 16 | rmc_status = ' '; |
tylerjw | 5:94daced1e61a | 17 | speed_k = 0.0; |
tylerjw | 5:94daced1e61a | 18 | course_d = 0.0; |
tylerjw | 5:94daced1e61a | 19 | date = 0; |
tylerjw | 5:94daced1e61a | 20 | |
tylerjw | 5:94daced1e61a | 21 | dec_longitude = 0.0; |
tylerjw | 5:94daced1e61a | 22 | dec_latitude = 0.0; |
tylerjw | 5:94daced1e61a | 23 | |
tylerjw | 5:94daced1e61a | 24 | gll_status = ' '; |
tylerjw | 5:94daced1e61a | 25 | |
tylerjw | 5:94daced1e61a | 26 | course_t = 0.0; // ground speed true |
tylerjw | 5:94daced1e61a | 27 | course_t_unit = ' '; |
tylerjw | 5:94daced1e61a | 28 | course_m = 0.0; // magnetic |
tylerjw | 5:94daced1e61a | 29 | course_m_unit = ' '; |
tylerjw | 5:94daced1e61a | 30 | speed_k_unit = ' '; |
tylerjw | 5:94daced1e61a | 31 | speed_km = 0.0; // speek km/hr |
tylerjw | 5:94daced1e61a | 32 | speed_km_unit = ' '; |
tylerjw | 5:94daced1e61a | 33 | |
tylerjw | 5:94daced1e61a | 34 | altitude_ft = 0.0; |
tylerjw | 5:94daced1e61a | 35 | } |
tylerjw | 5:94daced1e61a | 36 | |
tylerjw | 5:94daced1e61a | 37 | float GPS_Parser::nmea_to_dec(float deg_coord, char nsew) |
tylerjw | 5:94daced1e61a | 38 | { |
tylerjw | 5:94daced1e61a | 39 | int degree = (int)(deg_coord/100); |
tylerjw | 5:94daced1e61a | 40 | float minutes = deg_coord - degree*100; |
tylerjw | 5:94daced1e61a | 41 | float dec_deg = minutes / 60; |
tylerjw | 5:94daced1e61a | 42 | float decimal = degree + dec_deg; |
tylerjw | 5:94daced1e61a | 43 | if (nsew == 'S' || nsew == 'W') { // return negative |
tylerjw | 5:94daced1e61a | 44 | decimal *= -1; |
tylerjw | 5:94daced1e61a | 45 | } |
tylerjw | 5:94daced1e61a | 46 | return decimal; |
tylerjw | 5:94daced1e61a | 47 | } |
tylerjw | 5:94daced1e61a | 48 | |
tylerjw | 5:94daced1e61a | 49 | int GPS_Parser::sample(char *msg) |
tylerjw | 5:94daced1e61a | 50 | { |
tylerjw | 5:94daced1e61a | 51 | int line_parsed = 0; |
tylerjw | 5:94daced1e61a | 52 | |
tylerjw | 5:94daced1e61a | 53 | // Check if it is a GPGGA msg (matches both locked and non-locked msg) |
tylerjw | 5:94daced1e61a | 54 | if (sscanf(msg, "$GPGGA,%f,%f,%c,%f,%c,%d,%d,%f,%f,%c", &utc_time, &nmea_latitude, &ns, &nmea_longitude, &ew, &lock, &satelites, &hdop, &msl_altitude, &msl_units) >= 1) { |
tylerjw | 5:94daced1e61a | 55 | line_parsed = GGA; |
tylerjw | 5:94daced1e61a | 56 | } |
tylerjw | 5:94daced1e61a | 57 | // Check if it is a GPRMC msg |
tylerjw | 5:94daced1e61a | 58 | else if (sscanf(msg, "$GPRMC,%f,%f,%c,%f,%c,%f,%f,%d", &utc_time, &nmea_latitude, &ns, &nmea_longitude, &ew, &speed_k, &course_d, &date) >= 1) { |
tylerjw | 5:94daced1e61a | 59 | line_parsed = RMC; |
tylerjw | 5:94daced1e61a | 60 | } |
tylerjw | 5:94daced1e61a | 61 | |
tylerjw | 5:94daced1e61a | 62 | if(satelites == 0) { |
tylerjw | 5:94daced1e61a | 63 | lock = 0; |
tylerjw | 5:94daced1e61a | 64 | } |
tylerjw | 5:94daced1e61a | 65 | if (!lock) { |
tylerjw | 5:94daced1e61a | 66 | return NO_LOCK; |
tylerjw | 5:94daced1e61a | 67 | } else if (line_parsed) { |
tylerjw | 5:94daced1e61a | 68 | return line_parsed; |
tylerjw | 5:94daced1e61a | 69 | } else { |
tylerjw | 5:94daced1e61a | 70 | return NOT_PARSED; |
tylerjw | 5:94daced1e61a | 71 | } |
tylerjw | 5:94daced1e61a | 72 | } |
tylerjw | 5:94daced1e61a | 73 | |
tylerjw | 5:94daced1e61a | 74 | |
tylerjw | 5:94daced1e61a | 75 | // INTERNAL FUNCTINS //////////////////////////////////////////////////////////// |
tylerjw | 5:94daced1e61a | 76 | float GPS_Parser::trunc(float v) |
tylerjw | 5:94daced1e61a | 77 | { |
tylerjw | 5:94daced1e61a | 78 | if (v < 0.0) { |
tylerjw | 5:94daced1e61a | 79 | v*= -1.0; |
tylerjw | 5:94daced1e61a | 80 | v = floor(v); |
tylerjw | 5:94daced1e61a | 81 | v*=-1.0; |
tylerjw | 5:94daced1e61a | 82 | } else { |
tylerjw | 5:94daced1e61a | 83 | v = floor(v); |
tylerjw | 5:94daced1e61a | 84 | } |
tylerjw | 5:94daced1e61a | 85 | return v; |
tylerjw | 5:94daced1e61a | 86 | } |
tylerjw | 5:94daced1e61a | 87 | |
tylerjw | 5:94daced1e61a | 88 | // GET FUNCTIONS ///////////////////////////////////////////////////////////////// |
tylerjw | 5:94daced1e61a | 89 | float GPS_Parser::get_msl_altitude() |
tylerjw | 5:94daced1e61a | 90 | { |
tylerjw | 5:94daced1e61a | 91 | if (!lock) |
tylerjw | 5:94daced1e61a | 92 | return 0.0; |
tylerjw | 5:94daced1e61a | 93 | else |
tylerjw | 5:94daced1e61a | 94 | return msl_altitude; |
tylerjw | 5:94daced1e61a | 95 | } |
tylerjw | 5:94daced1e61a | 96 | |
tylerjw | 5:94daced1e61a | 97 | int GPS_Parser::get_satelites() |
tylerjw | 5:94daced1e61a | 98 | { |
tylerjw | 5:94daced1e61a | 99 | if (!lock) |
tylerjw | 5:94daced1e61a | 100 | return 0; |
tylerjw | 5:94daced1e61a | 101 | else |
tylerjw | 5:94daced1e61a | 102 | return satelites; |
tylerjw | 5:94daced1e61a | 103 | } |
tylerjw | 5:94daced1e61a | 104 | |
tylerjw | 5:94daced1e61a | 105 | float GPS_Parser::get_nmea_longitude() |
tylerjw | 5:94daced1e61a | 106 | { |
tylerjw | 5:94daced1e61a | 107 | if (!lock) |
tylerjw | 5:94daced1e61a | 108 | return 0.0; |
tylerjw | 5:94daced1e61a | 109 | else |
tylerjw | 5:94daced1e61a | 110 | return nmea_longitude; |
tylerjw | 5:94daced1e61a | 111 | } |
tylerjw | 5:94daced1e61a | 112 | |
tylerjw | 5:94daced1e61a | 113 | float GPS_Parser::get_dec_longitude() |
tylerjw | 5:94daced1e61a | 114 | { |
tylerjw | 5:94daced1e61a | 115 | dec_longitude = nmea_to_dec(nmea_longitude, ew); |
tylerjw | 5:94daced1e61a | 116 | if (!lock) |
tylerjw | 5:94daced1e61a | 117 | return 0.0; |
tylerjw | 5:94daced1e61a | 118 | else |
tylerjw | 5:94daced1e61a | 119 | return dec_longitude; |
tylerjw | 5:94daced1e61a | 120 | } |
tylerjw | 5:94daced1e61a | 121 | |
tylerjw | 5:94daced1e61a | 122 | float GPS_Parser::get_nmea_latitude() |
tylerjw | 5:94daced1e61a | 123 | { |
tylerjw | 5:94daced1e61a | 124 | if (!lock) |
tylerjw | 5:94daced1e61a | 125 | return 0.0; |
tylerjw | 5:94daced1e61a | 126 | else |
tylerjw | 5:94daced1e61a | 127 | return nmea_latitude; |
tylerjw | 5:94daced1e61a | 128 | } |
tylerjw | 5:94daced1e61a | 129 | |
tylerjw | 5:94daced1e61a | 130 | float GPS_Parser::get_dec_latitude() |
tylerjw | 5:94daced1e61a | 131 | { |
tylerjw | 5:94daced1e61a | 132 | dec_latitude = nmea_to_dec(nmea_latitude, ns); |
tylerjw | 5:94daced1e61a | 133 | if (!lock) |
tylerjw | 5:94daced1e61a | 134 | return 0.0; |
tylerjw | 5:94daced1e61a | 135 | else |
tylerjw | 5:94daced1e61a | 136 | return dec_latitude; |
tylerjw | 5:94daced1e61a | 137 | } |
tylerjw | 5:94daced1e61a | 138 | |
tylerjw | 5:94daced1e61a | 139 | float GPS_Parser::get_course_t() |
tylerjw | 5:94daced1e61a | 140 | { |
tylerjw | 5:94daced1e61a | 141 | if (!lock) |
tylerjw | 5:94daced1e61a | 142 | return 0.0; |
tylerjw | 5:94daced1e61a | 143 | else |
tylerjw | 5:94daced1e61a | 144 | return course_t; |
tylerjw | 5:94daced1e61a | 145 | } |
tylerjw | 5:94daced1e61a | 146 | |
tylerjw | 5:94daced1e61a | 147 | float GPS_Parser::get_course_m() |
tylerjw | 5:94daced1e61a | 148 | { |
tylerjw | 5:94daced1e61a | 149 | if (!lock) |
tylerjw | 5:94daced1e61a | 150 | return 0.0; |
tylerjw | 5:94daced1e61a | 151 | else |
tylerjw | 5:94daced1e61a | 152 | return course_m; |
tylerjw | 5:94daced1e61a | 153 | } |
tylerjw | 5:94daced1e61a | 154 | |
tylerjw | 5:94daced1e61a | 155 | float GPS_Parser::get_speed_k() |
tylerjw | 5:94daced1e61a | 156 | { |
tylerjw | 5:94daced1e61a | 157 | if (!lock) |
tylerjw | 5:94daced1e61a | 158 | return 0.0; |
tylerjw | 5:94daced1e61a | 159 | else |
tylerjw | 5:94daced1e61a | 160 | return speed_k; |
tylerjw | 5:94daced1e61a | 161 | } |
tylerjw | 5:94daced1e61a | 162 | |
tylerjw | 5:94daced1e61a | 163 | float GPS_Parser::get_speed_km() |
tylerjw | 5:94daced1e61a | 164 | { |
tylerjw | 5:94daced1e61a | 165 | if (!lock) |
tylerjw | 5:94daced1e61a | 166 | return 0.0; |
tylerjw | 5:94daced1e61a | 167 | else |
tylerjw | 5:94daced1e61a | 168 | return speed_km; |
tylerjw | 5:94daced1e61a | 169 | } |
tylerjw | 5:94daced1e61a | 170 | |
tylerjw | 5:94daced1e61a | 171 | float GPS_Parser::get_altitude_ft() |
tylerjw | 5:94daced1e61a | 172 | { |
tylerjw | 5:94daced1e61a | 173 | if (!lock) |
tylerjw | 5:94daced1e61a | 174 | return 0.0; |
tylerjw | 5:94daced1e61a | 175 | else |
tylerjw | 5:94daced1e61a | 176 | return 3.280839895*msl_altitude; |
tylerjw | 5:94daced1e61a | 177 | } |
tylerjw | 5:94daced1e61a | 178 | |
tylerjw | 5:94daced1e61a | 179 | // NAVIGATION FUNCTIONS //////////////////////////////////////////////////////////// |
tylerjw | 5:94daced1e61a | 180 | float GPS_Parser::calc_course_to(float pointLat, float pontLong) |
tylerjw | 5:94daced1e61a | 181 | { |
tylerjw | 5:94daced1e61a | 182 | const double d2r = PI / 180.0; |
tylerjw | 5:94daced1e61a | 183 | const double r2d = 180.0 / PI; |
tylerjw | 5:94daced1e61a | 184 | double dlat = abs(pointLat - get_dec_latitude()) * d2r; |
tylerjw | 5:94daced1e61a | 185 | double dlong = abs(pontLong - get_dec_longitude()) * d2r; |
tylerjw | 5:94daced1e61a | 186 | double y = sin(dlong) * cos(pointLat * d2r); |
tylerjw | 5:94daced1e61a | 187 | double x = cos(get_dec_latitude()*d2r)*sin(pointLat*d2r) - sin(get_dec_latitude()*d2r)*cos(pointLat*d2r)*cos(dlong); |
tylerjw | 5:94daced1e61a | 188 | return 360.0-(atan2(y,x)*r2d); |
tylerjw | 5:94daced1e61a | 189 | } |
tylerjw | 5:94daced1e61a | 190 | |
tylerjw | 5:94daced1e61a | 191 | /* |
tylerjw | 5:94daced1e61a | 192 | var y = Math.sin(dLon) * Math.cos(lat2); |
tylerjw | 5:94daced1e61a | 193 | var x = Math.cos(lat1)*Math.sin(lat2) - |
tylerjw | 5:94daced1e61a | 194 | Math.sin(lat1)*Math.cos(lat2)*Math.cos(dLon); |
tylerjw | 5:94daced1e61a | 195 | var brng = Math.atan2(y, x).toDeg(); |
tylerjw | 5:94daced1e61a | 196 | */ |
tylerjw | 5:94daced1e61a | 197 | |
tylerjw | 5:94daced1e61a | 198 | /* |
tylerjw | 5:94daced1e61a | 199 | The Haversine formula according to Dr. Math. |
tylerjw | 5:94daced1e61a | 200 | http://mathforum.org/library/drmath/view/51879.html |
tylerjw | 5:94daced1e61a | 201 | |
tylerjw | 5:94daced1e61a | 202 | dlon = lon2 - lon1 |
tylerjw | 5:94daced1e61a | 203 | dlat = lat2 - lat1 |
tylerjw | 5:94daced1e61a | 204 | a = (sin(dlat/2))^2 + cos(lat1) * cos(lat2) * (sin(dlon/2))^2 |
tylerjw | 5:94daced1e61a | 205 | c = 2 * atan2(sqrt(a), sqrt(1-a)) |
tylerjw | 5:94daced1e61a | 206 | d = R * c |
tylerjw | 5:94daced1e61a | 207 | |
tylerjw | 5:94daced1e61a | 208 | Where |
tylerjw | 5:94daced1e61a | 209 | * dlon is the change in longitude |
tylerjw | 5:94daced1e61a | 210 | * dlat is the change in latitude |
tylerjw | 5:94daced1e61a | 211 | * c is the great circle distance in Radians. |
tylerjw | 5:94daced1e61a | 212 | * R is the radius of a spherical Earth. |
tylerjw | 5:94daced1e61a | 213 | * The locations of the two points in |
tylerjw | 5:94daced1e61a | 214 | spherical coordinates (longitude and |
tylerjw | 5:94daced1e61a | 215 | latitude) are lon1,lat1 and lon2, lat2. |
tylerjw | 5:94daced1e61a | 216 | */ |
tylerjw | 5:94daced1e61a | 217 | double GPS_Parser::calc_dist_to_mi(float pointLat, float pontLong) |
tylerjw | 5:94daced1e61a | 218 | { |
tylerjw | 5:94daced1e61a | 219 | const double d2r = PI / 180.0; |
tylerjw | 5:94daced1e61a | 220 | double dlat = pointLat - get_dec_latitude(); |
tylerjw | 5:94daced1e61a | 221 | double dlong = pontLong - get_dec_longitude(); |
tylerjw | 5:94daced1e61a | 222 | double a = pow(sin(dlat/2.0),2.0) + cos(get_dec_latitude()*d2r) * cos(pointLat*d2r) * pow(sin(dlong/2.0),2.0); |
tylerjw | 5:94daced1e61a | 223 | double c = 2.0 * asin(sqrt(abs(a))); |
tylerjw | 5:94daced1e61a | 224 | double d = 63.765 * c; |
tylerjw | 5:94daced1e61a | 225 | |
tylerjw | 5:94daced1e61a | 226 | return d; |
tylerjw | 5:94daced1e61a | 227 | } |
tylerjw | 5:94daced1e61a | 228 | |
tylerjw | 5:94daced1e61a | 229 | double GPS_Parser::calc_dist_to_ft(float pointLat, float pontLong) |
tylerjw | 5:94daced1e61a | 230 | { |
tylerjw | 5:94daced1e61a | 231 | return calc_dist_to_mi(pointLat, pontLong)*5280.0; |
tylerjw | 5:94daced1e61a | 232 | } |
tylerjw | 5:94daced1e61a | 233 | |
tylerjw | 5:94daced1e61a | 234 | double GPS_Parser::calc_dist_to_km(float pointLat, float pontLong) |
tylerjw | 5:94daced1e61a | 235 | { |
tylerjw | 5:94daced1e61a | 236 | return calc_dist_to_mi(pointLat, pontLong)*1.609344; |
tylerjw | 5:94daced1e61a | 237 | } |
tylerjw | 5:94daced1e61a | 238 | |
tylerjw | 5:94daced1e61a | 239 | double GPS_Parser::calc_dist_to_m(float pointLat, float pontLong) |
tylerjw | 5:94daced1e61a | 240 | { |
tylerjw | 5:94daced1e61a | 241 | return calc_dist_to_mi(pointLat, pontLong)*1609.344; |
tylerjw | 5:94daced1e61a | 242 | } |
tylerjw | 5:94daced1e61a | 243 |