Port of Arduino TinyGPS library to mbed. Added extra methods to flag receipt/parsing of particular sentences.
Fork of TinyGPS by
TinyGPS.cpp
- Committer:
- sonson
- Date:
- 2017-05-10
- Revision:
- 2:af534d51739f
- Parent:
- 1:f522b8bdf987
File content as of revision 2:af534d51739f:
/* TinyGPS - a small GPS library for Arduino providing basic NMEA parsing Copyright (C) 2008-9 Mikal Hart All rights reserved. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Ported to mbed by Michael Shimniok http://www.bot-thoughts.com/ */ #include "TinyGPS.h" #define _GPRMC_TERM "GPRMC" #define _GPGGA_TERM "GPGGA" #define _GPGSV_TERM "GPGSV" TinyGPS::TinyGPS() : _time(GPS_INVALID_TIME) , _date(GPS_INVALID_DATE) , _latitude(GPS_INVALID_ANGLE) , _longitude(GPS_INVALID_ANGLE) , _altitude(GPS_INVALID_ALTITUDE) , _speed(GPS_INVALID_SPEED) , _course(GPS_INVALID_ANGLE) , _hdop(0) , _sat_count(0) , _last_time_fix(GPS_INVALID_FIX_TIME) , _last_position_fix(GPS_INVALID_FIX_TIME) , _parity(0) , _is_checksum_term(false) , _sentence_type(_GPS_SENTENCE_OTHER) , _term_number(0) , _term_offset(0) , _gps_data_good(false) , _rmc_ready(false) , _gga_ready(false) , _gsv_ready(false) #ifndef _GPS_NO_STATS , _encoded_characters(0) , _good_sentences(0) , _failed_checksum(0) #endif { _term[0] = '\0'; } // // public methods // bool TinyGPS::encode(char c) { bool valid_sentence = false; ++_encoded_characters; switch(c) { case ',': // term terminators _parity ^= c; case '\r': case '\n': case '*': if (_term_offset < sizeof(_term)) { _term[_term_offset] = 0; valid_sentence = term_complete(); } ++_term_number; _term_offset = 0; _is_checksum_term = c == '*'; return valid_sentence; case '$': // sentence begin _term_number = _term_offset = 0; _parity = 0; _sentence_type = _GPS_SENTENCE_OTHER; _is_checksum_term = false; _gps_data_good = false; return valid_sentence; } // ordinary characters if (_term_offset < sizeof(_term) - 1) _term[_term_offset++] = c; if (!_is_checksum_term) _parity ^= c; return valid_sentence; } #ifndef _GPS_NO_STATS void TinyGPS::stats(unsigned long *chars, unsigned short *sentences, unsigned short *failed_cs) { if (chars) *chars = _encoded_characters; if (sentences) *sentences = _good_sentences; if (failed_cs) *failed_cs = _failed_checksum; } #endif // // internal utilities // int TinyGPS::from_hex(char a) { if (a >= 'A' && a <= 'F') return a - 'A' + 10; else if (a >= 'a' && a <= 'f') return a - 'a' + 10; else return a - '0'; } unsigned long TinyGPS::parse_decimal() { char *p = _term; bool isneg = *p == '-'; if (isneg) ++p; unsigned long ret = 100UL * gpsatol(p); while (gpsisdigit(*p)) ++p; if (*p == '.') { if (gpsisdigit(p[1])) { ret += 10 * (p[1] - '0'); if (gpsisdigit(p[2])) ret += p[2] - '0'; } } return isneg ? -ret : ret; } unsigned long TinyGPS::parse_degrees() { char *p; unsigned long left = gpsatol(_term); unsigned long tenk_minutes = (left % 100UL) * 10000UL; for (p=_term; gpsisdigit(*p); ++p); if (*p == '.') { unsigned long mult = 1000; while (gpsisdigit(*++p)) { tenk_minutes += mult * (*p - '0'); mult /= 10; } } return (left / 100) * 100000 + tenk_minutes / 6; } // Processes a just-completed term // Returns true if new sentence has just passed checksum test and is validated bool TinyGPS::term_complete() { if (_is_checksum_term) { byte checksum = 16 * from_hex(_term[0]) + from_hex(_term[1]); if (checksum == _parity) { if (_gps_data_good) { #ifndef _GPS_NO_STATS ++_good_sentences; #endif _last_time_fix = _new_time_fix; _last_position_fix = _new_position_fix; switch(_sentence_type) { case _GPS_SENTENCE_GPRMC: _time = _new_time; _date = _new_date; _latitude = _new_latitude; _longitude = _new_longitude; _speed = _new_speed; _course = _new_course; _rmc_ready = true; break; case _GPS_SENTENCE_GPGGA: _altitude = _new_altitude; _time = _new_time; _latitude = _new_latitude; _longitude = _new_longitude; _gga_ready = true; _hdop = _new_hdop; _sat_count = _new_sat_count; case _GPS_SENTENCE_GPGSV: _gsv_ready = true; break; } return true; } } #ifndef _GPS_NO_STATS else ++_failed_checksum; #endif return false; } // the first term determines the sentence type if (_term_number == 0) { if (!gpsstrcmp(_term, _GPRMC_TERM)) _sentence_type = _GPS_SENTENCE_GPRMC; else if (!gpsstrcmp(_term, _GPGGA_TERM)) _sentence_type = _GPS_SENTENCE_GPGGA; else if (!gpsstrcmp(_term, _GPGSV_TERM)) _sentence_type = _GPS_SENTENCE_GPGSV; else _sentence_type = _GPS_SENTENCE_OTHER; return false; } if (_sentence_type != _GPS_SENTENCE_OTHER && _term[0]) switch((_sentence_type == _GPS_SENTENCE_GPGGA ? 200 : 100) + _term_number) { case 101: // Time in both sentences case 201: _new_time = parse_decimal(); _new_time_fix = millis(); break; case 102: // GPRMC validity _gps_data_good = _term[0] == 'A'; break; case 103: // Latitude case 202: _new_latitude = parse_degrees(); _new_position_fix = millis(); break; case 104: // N/S case 203: if (_term[0] == 'S') _new_latitude = -_new_latitude; break; case 105: // Longitude case 204: _new_longitude = parse_degrees(); break; case 106: // E/W case 205: if (_term[0] == 'W') _new_longitude = -_new_longitude; break; case 107: // Speed (GPRMC) _new_speed = parse_decimal(); break; case 108: // Course (GPRMC) _new_course = parse_decimal(); break; case 109: // Date (GPRMC) _new_date = gpsatol(_term); break; case 206: // Fix data (GPGGA) _gps_data_good = _term[0] > '0'; break; case 207: // Number of satelites tracked (GPGGA) _new_sat_count = parse_decimal(); break; case 208: // Horizontal Dilution of Position (GPGGA) _new_hdop = parse_decimal(); break; case 209: // Altitude (GPGGA) _new_altitude = parse_decimal(); break; } /* switch */ return false; } long TinyGPS::gpsatol(const char *str) { long ret = 0; while (gpsisdigit(*str)) ret = 10 * ret + *str++ - '0'; return ret; } int TinyGPS::gpsstrcmp(const char *str1, const char *str2) { while (*str1 && *str1 == *str2) ++str1, ++str2; return *str1; }