From 8e57c683d3d16f1dee320f10c411602ea38ba651 Mon Sep 17 00:00:00 2001 From: Stanley Huang Date: Mon, 25 Mar 2013 00:57:28 +0800 Subject: initial commit --- obdlogger/TinyGPS.cpp | 426 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 426 insertions(+) create mode 100644 obdlogger/TinyGPS.cpp (limited to 'obdlogger/TinyGPS.cpp') diff --git a/obdlogger/TinyGPS.cpp b/obdlogger/TinyGPS.cpp new file mode 100644 index 0000000..00a683c --- /dev/null +++ b/obdlogger/TinyGPS.cpp @@ -0,0 +1,426 @@ +/* +TinyGPS - a small GPS library for Arduino providing basic NMEA parsing +Based on work by and "distance_to" and "course_to" courtesy of Maarten Lamers. +Suggestion to add satellites(), course_to(), and cardinal(), by Matt Monson. +Copyright (C) 2008-2012 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 +*/ + +#include "TinyGPS.h" + +#define _GPRMC_TERM "GPRMC" +#define _GPGGA_TERM "GPGGA" + +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(GPS_INVALID_HDOP) + , _numsats(GPS_INVALID_SATELLITES) + , _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) +#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; + +#ifndef _GPS_NO_STATS + ++_encoded_characters; +#endif + 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; +} + +#define COMBINE(sentence_type, term_number) (((unsigned)(sentence_type) << 5) | term_number) + +// 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; + break; + case _GPS_SENTENCE_GPGGA: + _altitude = _new_altitude; + _time = _new_time; + _latitude = _new_latitude; + _longitude = _new_longitude; + _numsats = _new_numsats; + _hdop = _new_hdop; + 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 + _sentence_type = _GPS_SENTENCE_OTHER; + return false; + } + + if (_sentence_type != _GPS_SENTENCE_OTHER && _term[0]) + switch(COMBINE(_sentence_type, _term_number)) + { + case COMBINE(_GPS_SENTENCE_GPRMC, 1): // Time in both sentences + case COMBINE(_GPS_SENTENCE_GPGGA, 1): + _new_time = parse_decimal(); + _new_time_fix = millis(); + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 2): // GPRMC validity + _gps_data_good = _term[0] == 'A'; + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 3): // Latitude + case COMBINE(_GPS_SENTENCE_GPGGA, 2): + _new_latitude = parse_degrees(); + _new_position_fix = millis(); + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 4): // N/S + case COMBINE(_GPS_SENTENCE_GPGGA, 3): + if (_term[0] == 'S') + _new_latitude = -_new_latitude; + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 5): // Longitude + case COMBINE(_GPS_SENTENCE_GPGGA, 4): + _new_longitude = parse_degrees(); + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 6): // E/W + case COMBINE(_GPS_SENTENCE_GPGGA, 5): + if (_term[0] == 'W') + _new_longitude = -_new_longitude; + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 7): // Speed (GPRMC) + _new_speed = parse_decimal(); + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 8): // Course (GPRMC) + _new_course = parse_decimal(); + break; + case COMBINE(_GPS_SENTENCE_GPRMC, 9): // Date (GPRMC) + _new_date = gpsatol(_term); + break; + case COMBINE(_GPS_SENTENCE_GPGGA, 6): // Fix data (GPGGA) + _gps_data_good = _term[0] > '0'; + break; + case COMBINE(_GPS_SENTENCE_GPGGA, 7): // Satellites used (GPGGA) + _new_numsats = (unsigned char)atoi(_term); + break; + case COMBINE(_GPS_SENTENCE_GPGGA, 8): // HDOP + _new_hdop = parse_decimal(); + break; + case COMBINE(_GPS_SENTENCE_GPGGA, 9): // Altitude (GPGGA) + _new_altitude = parse_decimal(); + break; + } + + 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; +} + +/* static */ +float TinyGPS::distance_between (float lat1, float long1, float lat2, float long2) +{ + // returns distance in meters between two positions, both specified + // as signed decimal-degrees latitude and longitude. Uses great-circle + // distance computation for hypothetical sphere of radius 6372795 meters. + // Because Earth is no exact sphere, rounding errors may be up to 0.5%. + // Courtesy of Maarten Lamers + float delta = radians(long1-long2); + float sdlong = sin(delta); + float cdlong = cos(delta); + lat1 = radians(lat1); + lat2 = radians(lat2); + float slat1 = sin(lat1); + float clat1 = cos(lat1); + float slat2 = sin(lat2); + float clat2 = cos(lat2); + delta = (clat1 * slat2) - (slat1 * clat2 * cdlong); + delta = sq(delta); + delta += sq(clat2 * sdlong); + delta = sqrt(delta); + float denom = (slat1 * slat2) + (clat1 * clat2 * cdlong); + delta = atan2(delta, denom); + return delta * 6372795; +} + +float TinyGPS::course_to (float lat1, float long1, float lat2, float long2) +{ + // returns course in degrees (North=0, West=270) from position 1 to position 2, + // both specified as signed decimal-degrees latitude and longitude. + // Because Earth is no exact sphere, calculated course may be off by a tiny fraction. + // Courtesy of Maarten Lamers + float dlon = radians(long2-long1); + lat1 = radians(lat1); + lat2 = radians(lat2); + float a1 = sin(dlon) * cos(lat2); + float a2 = sin(lat1) * cos(lat2) * cos(dlon); + a2 = cos(lat1) * sin(lat2) - a2; + a2 = atan2(a1, a2); + if (a2 < 0.0) + { + a2 += TWO_PI; + } + return degrees(a2); +} + +const char *TinyGPS::cardinal (float course) +{ + static const char* directions[] = {"N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE", "S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW"}; + + int direction = (int)((course + 11.25f) / 22.5f); + return directions[direction % 16]; +} + +// lat/long in hundred thousandths of a degree and age of fix in milliseconds +void TinyGPS::get_position(long *latitude, long *longitude, unsigned long *fix_age) +{ + if (latitude) *latitude = _latitude; + if (longitude) *longitude = _longitude; + if (fix_age) *fix_age = _last_position_fix == GPS_INVALID_FIX_TIME ? +GPS_INVALID_AGE : millis() - _last_position_fix; +} + +// date as ddmmyy, time as hhmmsscc, and age in milliseconds +void TinyGPS::get_datetime(unsigned long *date, unsigned long *time, unsigned long *age) +{ + if (date) *date = _date; + if (time) *time = _time; + if (age) *age = _last_time_fix == GPS_INVALID_FIX_TIME ? +GPS_INVALID_AGE : millis() - _last_time_fix; +} + +void TinyGPS::f_get_position(float *latitude, float *longitude, unsigned long *fix_age) +{ + long lat, lon; + get_position(&lat, &lon, fix_age); + *latitude = lat == GPS_INVALID_ANGLE ? GPS_INVALID_F_ANGLE : (lat / 100000.0); + *longitude = lat == GPS_INVALID_ANGLE ? GPS_INVALID_F_ANGLE : (lon / 100000.0); +} + +void TinyGPS::crack_datetime(int *year, byte *month, byte *day, + byte *hour, byte *minute, byte *second, byte *hundredths, unsigned long *age) +{ + unsigned long date, time; + get_datetime(&date, &time, age); + if (year) + { + *year = date % 100; + *year += *year > 80 ? 1900 : 2000; + } + if (month) *month = (date / 100) % 100; + if (day) *day = date / 10000; + if (hour) *hour = time / 1000000; + if (minute) *minute = (time / 10000) % 100; + if (second) *second = (time / 100) % 100; + if (hundredths) *hundredths = time % 100; +} + +float TinyGPS::f_altitude() +{ + return _altitude == GPS_INVALID_ALTITUDE ? GPS_INVALID_F_ALTITUDE : _altitude / 100.0; +} + +float TinyGPS::f_course() +{ + return _course == GPS_INVALID_ANGLE ? GPS_INVALID_F_ANGLE : _course / 100.0; +} + +float TinyGPS::f_speed_knots() +{ + return _speed == GPS_INVALID_SPEED ? GPS_INVALID_F_SPEED : _speed / 100.0; +} + +float TinyGPS::f_speed_mph() +{ + float sk = f_speed_knots(); + return sk == GPS_INVALID_F_SPEED ? GPS_INVALID_F_SPEED : _GPS_MPH_PER_KNOT * f_speed_knots(); +} + +float TinyGPS::f_speed_mps() +{ + float sk = f_speed_knots(); + return sk == GPS_INVALID_F_SPEED ? GPS_INVALID_F_SPEED : _GPS_MPS_PER_KNOT * f_speed_knots(); +} + +float TinyGPS::f_speed_kmph() +{ + float sk = f_speed_knots(); + return sk == GPS_INVALID_F_SPEED ? GPS_INVALID_F_SPEED : _GPS_KMPH_PER_KNOT * f_speed_knots(); +} + +const float TinyGPS::GPS_INVALID_F_ANGLE = 1000.0; +const float TinyGPS::GPS_INVALID_F_ALTITUDE = 1000000.0; +const float TinyGPS::GPS_INVALID_F_SPEED = -1.0; -- cgit v1.2.3