A GPS serial interrupt service routine that has an on the fly nmea parser. Works with a STM32F411RE and a Adafruit GPS logger.
Dependents: Bicycl_Computer_NUCLEO-F411RE Bicycl_Computer_NUCLEO-L476RG
Fork of GPS by
main.cpp
#include "mbed.h" #include "GPSISR.h" #define PIN_RX_GPS PA_12 //GPS Shield RX pin #define PIN_TX_GPS PA_11 //GPS Shield TX pin Serial pc(USBTX, USBRX); // Set up serial interrupe service handler for gps characters. GPS MyGPS(PIN_TX_GPS,PIN_RX_GPS, 9600); int main() { while (1) { if (MyGPS.dataready()) { MyGPS.read(); pc.printf("NMEA has valid data"); pc.printf("Sats : %d \n", MyGPS.buffer.satellites); pc.printf("%d-%d-%d\n", MyGPS.buffer.month, MyGPS.buffer.day, MyGPS.buffer.year); pc.printf("%d:%d:%d\n", MyGPS.buffer.hours, MyGPS.buffer.minutes, MyGPS.buffer.seconds); } else { pc.printf("NMEA has no valid data"); } } }
nmea.h
- Committer:
- trevieze
- Date:
- 2017-03-01
- Revision:
- 6:f0c13bb7d266
- Parent:
- 5:c5f700c1e1af
File content as of revision 6:f0c13bb7d266:
/* File: nmea.h Version: 0.1.0 Date: Feb. 23, 2013 License: GPL v2 NMEA GPS content parser **************************************************************************** Copyright (C) 2013 Radu Motisan <radu.motisan@gmail.com> http://www.pocketmagic.net This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA **************************************************************************** */ //#include "../timeout.h" class NMEA { private: bool m_bFlagRead, // flag used by the parser, when a valid sentence has begun m_bFlagDataReady; // valid GPS fix and data available, user can call reader functions char tmp_words[20][15], // hold parsed words for one given NMEA sentence tmp_szChecksum[15]; // hold the received checksum for one given NMEA sentence // will be set to true for characters between $ and * only bool m_bFlagComputedCks ; // used to compute checksum and indicate valid checksum interval (between $ and * in a given sentence) int m_nChecksum ; // numeric checksum, computed for a given sentence bool m_bFlagReceivedCks ; // after getting * we start cuttings the received checksum int index_received_checksum ; // used to parse received checksum // word cutting variables int m_nWordIdx , // the current word in a sentence m_nPrevIdx, // last character index where we did a cut m_nNowIdx ; // current character index // globals to store parser results float res_fLongitude; // GPRMC and GPGGA char res_clon; // E or W float res_fLatitude; // GPRMC and GPGGA char res_clat; // N or S unsigned char res_nUTCHour, res_nUTCMin, res_nUTCSec, // GPRMC and GPGGA res_nUTCDay, res_nUTCMonth, res_nUTCYear; // GPRMC int res_nSatellitesUsed; // GPGGA float res_fAltitude; // GPGGA float res_fSpeed; // GPRMC float res_fBearing; // GPRMC // the parser, currently handling GPRMC and GPGGA, but easy to add any new sentences void parsedata(); // aux functions int digit2dec(char hexdigit); float string2float(char* s); int mstrcmp(const char *s1, const char *s2); float trunc(float v); public: // constructor, initing a few variables NMEA() { m_bFlagRead = false; //are we in a sentence? m_bFlagDataReady = false; //is data available? } /* * The serial data is assembled on the fly, without using any redundant buffers. * When a sentence is complete (one that starts with $, ending in EOL), all processing is done on * this temporary buffer that we've built: checksum computation, extracting sentence "words" (the CSV values), * and so on. * When a new sentence is fully assembled using the fusedata function, the code calls parsedata. * This function in turn, splits the sentences and interprets the data. Here is part of the parser function, * handling both the $GPRMC NMEA sentence: */ int fusedata(char c); // READER functions: retrieving results, call isdataready() first bool isdataready(); int getHour(); int getMinute(); int getSecond(); int getDay(); int getMonth(); int getYear(); float getLatitude(); char getlatc(); float getLongitude(); char getlonc(); int getSatellites(); float getAltitude(); float getSpeed(); float getBearing(); };