nmea gps library - without any serial

Dependents:   HARP2 HARP3 20180621_FT813

Fork of GPS_parser by Tyler Weaver

NMEA GPS Serial Output parser.

Routine taken from NMEA Software Standard (NMEA 0183) http://www.winsystems.com/software/nmea.pdf

Only handles GGA and RMC Messages

Files at this revision

API Documentation at this revision

Comitter:
tylerjw
Date:
Wed Dec 12 17:32:31 2012 +0000
Parent:
4:6e2d98b5cb86
Child:
6:4ed12067a314
Commit message:
bug fix

Changed in this revision

GPS.cpp Show diff for this revision Revisions of this file
GPS.h Show diff for this revision Revisions of this file
GPS_parser.cpp Show annotated file Show diff for this revision Revisions of this file
GPS_parser.h Show annotated file Show diff for this revision Revisions of this file
--- a/GPS.cpp	Wed Dec 12 17:22:45 2012 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,243 +0,0 @@
-#include "GPS.h"
-
-GPS::GPS()
-{
-    nmea_longitude = 0.0;
-    nmea_latitude = 0.0;
-    utc_time = 0;
-    ns = ' ';
-    ew = ' ';
-    lock = 0;
-    satelites = 0;
-    hdop = 0.0;
-    msl_altitude = 0.0;
-    msl_units = ' ';
-
-    rmc_status = ' ';
-    speed_k = 0.0;
-    course_d = 0.0;
-    date = 0;
-
-    dec_longitude = 0.0;
-    dec_latitude = 0.0;
-
-    gll_status = ' ';
-
-    course_t = 0.0; // ground speed true
-    course_t_unit = ' ';
-    course_m = 0.0; // magnetic
-    course_m_unit = ' ';
-    speed_k_unit = ' ';
-    speed_km = 0.0; // speek km/hr
-    speed_km_unit = ' ';
-
-    altitude_ft = 0.0;
-}
-
-float GPS::nmea_to_dec(float deg_coord, char nsew)
-{
-    int degree = (int)(deg_coord/100);
-    float minutes = deg_coord - degree*100;
-    float dec_deg = minutes / 60;
-    float decimal = degree + dec_deg;
-    if (nsew == 'S' || nsew == 'W') { // return negative
-        decimal *= -1;
-    }
-    return decimal;
-}
-
-int GPS::sample(char *msg)
-{
-    int line_parsed = 0;
-
-    // Check if it is a GPGGA msg (matches both locked and non-locked msg)
-    if (sscanf(msg, "$GPGGA,%f,%f,%c,%f,%c,%d,%d,%f,%f,%c", &utc_time, &nmea_latitude, &ns, &nmea_longitude, &ew, &lock, &satelites, &hdop, &msl_altitude, &msl_units) >= 1) {
-        line_parsed = GGA;
-    }
-    // Check if it is a GPRMC msg
-    else if (sscanf(msg, "$GPRMC,%f,%f,%c,%f,%c,%f,%f,%d", &utc_time, &nmea_latitude, &ns, &nmea_longitude, &ew, &speed_k, &course_d, &date) >= 1) {
-        line_parsed = RMC;
-    }
-
-    if(satelites == 0) {
-        lock = 0;
-    }
-    if (!lock) {
-        return NO_LOCK;
-    } else if (line_parsed) {
-        return line_parsed;
-    } else {
-        return NOT_PARSED;
-    }
-}
-
-
-// INTERNAL FUNCTINS ////////////////////////////////////////////////////////////
-float GPS::trunc(float v)
-{
-    if (v < 0.0) {
-        v*= -1.0;
-        v = floor(v);
-        v*=-1.0;
-    } else {
-        v = floor(v);
-    }
-    return v;
-}
-
-// GET FUNCTIONS /////////////////////////////////////////////////////////////////
-float GPS::get_msl_altitude()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return msl_altitude;
-}
-
-int GPS::get_satelites()
-{
-    if (!lock)
-        return 0;
-    else
-        return satelites;
-}
-
-float GPS::get_nmea_longitude()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return nmea_longitude;
-}
-
-float GPS::get_dec_longitude()
-{
-    dec_longitude = nmea_to_dec(nmea_longitude, ew);
-    if (!lock)
-        return 0.0;
-    else
-        return dec_longitude;
-}
-
-float GPS::get_nmea_latitude()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return nmea_latitude;
-}
-
-float GPS::get_dec_latitude()
-{
-    dec_latitude = nmea_to_dec(nmea_latitude, ns);
-    if (!lock)
-        return 0.0;
-    else
-        return dec_latitude;
-}
-
-float GPS::get_course_t()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return course_t;
-}
-
-float GPS::get_course_m()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return course_m;
-}
-
-float GPS::get_speed_k()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return speed_k;
-}
-
-float GPS::get_speed_km()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return speed_km;
-}
-
-float GPS::get_altitude_ft()
-{
-    if (!lock)
-        return 0.0;
-    else
-        return 3.280839895*msl_altitude;
-}
-
-// NAVIGATION FUNCTIONS ////////////////////////////////////////////////////////////
-float GPS::calc_course_to(float pointLat, float pontLong)
-{
-    const double d2r = PI / 180.0;
-    const double r2d = 180.0 / PI;
-    double dlat = abs(pointLat - get_dec_latitude()) * d2r;
-    double dlong = abs(pontLong - get_dec_longitude()) * d2r;
-    double y = sin(dlong) * cos(pointLat * d2r);
-    double x = cos(get_dec_latitude()*d2r)*sin(pointLat*d2r) - sin(get_dec_latitude()*d2r)*cos(pointLat*d2r)*cos(dlong);
-    return 360.0-(atan2(y,x)*r2d);
-}
-
-/*
-var y = Math.sin(dLon) * Math.cos(lat2);
-var x = Math.cos(lat1)*Math.sin(lat2) -
-        Math.sin(lat1)*Math.cos(lat2)*Math.cos(dLon);
-var brng = Math.atan2(y, x).toDeg();
-*/
-
-/*
-            The Haversine formula according to Dr. Math.
-            http://mathforum.org/library/drmath/view/51879.html
-
-            dlon = lon2 - lon1
-            dlat = lat2 - lat1
-            a = (sin(dlat/2))^2 + cos(lat1) * cos(lat2) * (sin(dlon/2))^2
-            c = 2 * atan2(sqrt(a), sqrt(1-a))
-            d = R * c
-
-            Where
-                * dlon is the change in longitude
-                * dlat is the change in latitude
-                * c is the great circle distance in Radians.
-                * R is the radius of a spherical Earth.
-                * The locations of the two points in
-                    spherical coordinates (longitude and
-                    latitude) are lon1,lat1 and lon2, lat2.
-*/
-double GPS::calc_dist_to_mi(float pointLat, float pontLong)
-{
-    const double d2r = PI / 180.0;
-    double dlat = pointLat - get_dec_latitude();
-    double dlong = pontLong - get_dec_longitude();
-    double a = pow(sin(dlat/2.0),2.0) + cos(get_dec_latitude()*d2r) * cos(pointLat*d2r) * pow(sin(dlong/2.0),2.0);
-    double c = 2.0 * asin(sqrt(abs(a)));
-    double d = 63.765 * c;
-
-    return d;
-}
-
-double GPS::calc_dist_to_ft(float pointLat, float pontLong)
-{
-    return calc_dist_to_mi(pointLat, pontLong)*5280.0;
-}
-
-double GPS::calc_dist_to_km(float pointLat, float pontLong)
-{
-    return calc_dist_to_mi(pointLat, pontLong)*1.609344;
-}
-
-double GPS::calc_dist_to_m(float pointLat, float pontLong)
-{
-    return calc_dist_to_mi(pointLat, pontLong)*1609.344;
-}
-
--- a/GPS.h	Wed Dec 12 17:22:45 2012 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,86 +0,0 @@
-#include "mbed.h"
-
-#ifndef MBED_GPS_H
-#define MBED_GPS_H
-
-#define NO_LOCK     1
-#define NOT_PARSED  2
-#define GGA         3
-#define GLL         4
-#define RMC         5
-#define VTG         6
-
-#define PI (3.141592653589793)
-
-/**  A GPS interface for reading from a Globalsat EM-406 GPS Module */
-class GPS {
-public:
-
-    /** Create the GPS interface, connected to the specified serial port
-     */    
-    GPS();
-    
-    /** Sample the incoming GPS data, returning whether there is a lock
-     * 
-     * @return 1 if there was a lock when the sample was taken (and therefore .longitude and .latitude are valid), else 0
-     */
-    int sample(char *);
-    float get_nmea_longitude();
-    float get_nmea_latitude();
-    float get_dec_longitude();
-    float get_dec_latitude();
-    float get_msl_altitude();
-    float get_course_t();
-    float get_course_m();
-    float get_speed_k();
-    float get_speed_km();
-    int get_satelites();
-    float get_altitude_ft();
-    
-    // navigational functions
-    float calc_course_to(float, float);
-    double calc_dist_to_mi(float, float);
-    double calc_dist_to_ft(float, float);
-    double calc_dist_to_km(float, float);
-    double calc_dist_to_m(float, float);
-    
-private:
-    float nmea_to_dec(float, char);
-    float trunc(float v);
-    
-    // calculated values
-    float dec_longitude;
-    float dec_latitude;
-    float altitude_ft;
-    
-    // GGA - Global Positioning System Fixed Data
-    float nmea_longitude;
-    float nmea_latitude;    
-    float utc_time;
-    char ns, ew;
-    int lock;
-    int satelites;
-    float hdop;
-    float msl_altitude;
-    char msl_units;
-    
-    // RMC - Recommended Minimmum Specific GNS Data
-    char rmc_status;
-    float speed_k;
-    float course_d;
-    int date;
-    
-    // GLL
-    char gll_status;
-    
-    // VTG - Course over ground, ground speed
-    float course_t; // ground speed true
-    char course_t_unit;
-    float course_m; // magnetic
-    char course_m_unit;
-    char speed_k_unit;
-    float speed_km; // speek km/hr
-    char speed_km_unit;
-};
-
-#endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS_parser.cpp	Wed Dec 12 17:32:31 2012 +0000
@@ -0,0 +1,243 @@
+#include "GPS_parser.h"
+
+GPS_Parser::GPS_Parser()
+{
+    nmea_longitude = 0.0;
+    nmea_latitude = 0.0;
+    utc_time = 0;
+    ns = ' ';
+    ew = ' ';
+    lock = 0;
+    satelites = 0;
+    hdop = 0.0;
+    msl_altitude = 0.0;
+    msl_units = ' ';
+
+    rmc_status = ' ';
+    speed_k = 0.0;
+    course_d = 0.0;
+    date = 0;
+
+    dec_longitude = 0.0;
+    dec_latitude = 0.0;
+
+    gll_status = ' ';
+
+    course_t = 0.0; // ground speed true
+    course_t_unit = ' ';
+    course_m = 0.0; // magnetic
+    course_m_unit = ' ';
+    speed_k_unit = ' ';
+    speed_km = 0.0; // speek km/hr
+    speed_km_unit = ' ';
+
+    altitude_ft = 0.0;
+}
+
+float GPS_Parser::nmea_to_dec(float deg_coord, char nsew)
+{
+    int degree = (int)(deg_coord/100);
+    float minutes = deg_coord - degree*100;
+    float dec_deg = minutes / 60;
+    float decimal = degree + dec_deg;
+    if (nsew == 'S' || nsew == 'W') { // return negative
+        decimal *= -1;
+    }
+    return decimal;
+}
+
+int GPS_Parser::sample(char *msg)
+{
+    int line_parsed = 0;
+
+    // Check if it is a GPGGA msg (matches both locked and non-locked msg)
+    if (sscanf(msg, "$GPGGA,%f,%f,%c,%f,%c,%d,%d,%f,%f,%c", &utc_time, &nmea_latitude, &ns, &nmea_longitude, &ew, &lock, &satelites, &hdop, &msl_altitude, &msl_units) >= 1) {
+        line_parsed = GGA;
+    }
+    // Check if it is a GPRMC msg
+    else if (sscanf(msg, "$GPRMC,%f,%f,%c,%f,%c,%f,%f,%d", &utc_time, &nmea_latitude, &ns, &nmea_longitude, &ew, &speed_k, &course_d, &date) >= 1) {
+        line_parsed = RMC;
+    }
+
+    if(satelites == 0) {
+        lock = 0;
+    }
+    if (!lock) {
+        return NO_LOCK;
+    } else if (line_parsed) {
+        return line_parsed;
+    } else {
+        return NOT_PARSED;
+    }
+}
+
+
+// INTERNAL FUNCTINS ////////////////////////////////////////////////////////////
+float GPS_Parser::trunc(float v)
+{
+    if (v < 0.0) {
+        v*= -1.0;
+        v = floor(v);
+        v*=-1.0;
+    } else {
+        v = floor(v);
+    }
+    return v;
+}
+
+// GET FUNCTIONS /////////////////////////////////////////////////////////////////
+float GPS_Parser::get_msl_altitude()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return msl_altitude;
+}
+
+int GPS_Parser::get_satelites()
+{
+    if (!lock)
+        return 0;
+    else
+        return satelites;
+}
+
+float GPS_Parser::get_nmea_longitude()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return nmea_longitude;
+}
+
+float GPS_Parser::get_dec_longitude()
+{
+    dec_longitude = nmea_to_dec(nmea_longitude, ew);
+    if (!lock)
+        return 0.0;
+    else
+        return dec_longitude;
+}
+
+float GPS_Parser::get_nmea_latitude()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return nmea_latitude;
+}
+
+float GPS_Parser::get_dec_latitude()
+{
+    dec_latitude = nmea_to_dec(nmea_latitude, ns);
+    if (!lock)
+        return 0.0;
+    else
+        return dec_latitude;
+}
+
+float GPS_Parser::get_course_t()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return course_t;
+}
+
+float GPS_Parser::get_course_m()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return course_m;
+}
+
+float GPS_Parser::get_speed_k()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return speed_k;
+}
+
+float GPS_Parser::get_speed_km()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return speed_km;
+}
+
+float GPS_Parser::get_altitude_ft()
+{
+    if (!lock)
+        return 0.0;
+    else
+        return 3.280839895*msl_altitude;
+}
+
+// NAVIGATION FUNCTIONS ////////////////////////////////////////////////////////////
+float GPS_Parser::calc_course_to(float pointLat, float pontLong)
+{
+    const double d2r = PI / 180.0;
+    const double r2d = 180.0 / PI;
+    double dlat = abs(pointLat - get_dec_latitude()) * d2r;
+    double dlong = abs(pontLong - get_dec_longitude()) * d2r;
+    double y = sin(dlong) * cos(pointLat * d2r);
+    double x = cos(get_dec_latitude()*d2r)*sin(pointLat*d2r) - sin(get_dec_latitude()*d2r)*cos(pointLat*d2r)*cos(dlong);
+    return 360.0-(atan2(y,x)*r2d);
+}
+
+/*
+var y = Math.sin(dLon) * Math.cos(lat2);
+var x = Math.cos(lat1)*Math.sin(lat2) -
+        Math.sin(lat1)*Math.cos(lat2)*Math.cos(dLon);
+var brng = Math.atan2(y, x).toDeg();
+*/
+
+/*
+            The Haversine formula according to Dr. Math.
+            http://mathforum.org/library/drmath/view/51879.html
+
+            dlon = lon2 - lon1
+            dlat = lat2 - lat1
+            a = (sin(dlat/2))^2 + cos(lat1) * cos(lat2) * (sin(dlon/2))^2
+            c = 2 * atan2(sqrt(a), sqrt(1-a))
+            d = R * c
+
+            Where
+                * dlon is the change in longitude
+                * dlat is the change in latitude
+                * c is the great circle distance in Radians.
+                * R is the radius of a spherical Earth.
+                * The locations of the two points in
+                    spherical coordinates (longitude and
+                    latitude) are lon1,lat1 and lon2, lat2.
+*/
+double GPS_Parser::calc_dist_to_mi(float pointLat, float pontLong)
+{
+    const double d2r = PI / 180.0;
+    double dlat = pointLat - get_dec_latitude();
+    double dlong = pontLong - get_dec_longitude();
+    double a = pow(sin(dlat/2.0),2.0) + cos(get_dec_latitude()*d2r) * cos(pointLat*d2r) * pow(sin(dlong/2.0),2.0);
+    double c = 2.0 * asin(sqrt(abs(a)));
+    double d = 63.765 * c;
+
+    return d;
+}
+
+double GPS_Parser::calc_dist_to_ft(float pointLat, float pontLong)
+{
+    return calc_dist_to_mi(pointLat, pontLong)*5280.0;
+}
+
+double GPS_Parser::calc_dist_to_km(float pointLat, float pontLong)
+{
+    return calc_dist_to_mi(pointLat, pontLong)*1.609344;
+}
+
+double GPS_Parser::calc_dist_to_m(float pointLat, float pontLong)
+{
+    return calc_dist_to_mi(pointLat, pontLong)*1609.344;
+}
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS_parser.h	Wed Dec 12 17:32:31 2012 +0000
@@ -0,0 +1,84 @@
+#include "mbed.h"
+
+#ifndef MBED_GPS_PARSER_H
+#define MBED_GPS_PARSER_H
+
+#define NO_LOCK     1
+#define NOT_PARSED  2
+#define GGA         3
+#define GLL         4
+#define RMC         5
+#define VTG         6
+
+#define PI (3.141592653589793)
+
+/**  A GPS_parser interface for reading from a Globalsat EM-406 GPS Module */
+class GPS_Parser {
+public:
+
+    GPS_Parser();
+    
+    /** Sample the incoming GPS data, returning whether there is a lock
+     * 
+     * @return 1 if there was a lock when the sample was taken (and therefore .longitude and .latitude are valid), else 0
+     */
+    int sample(char *);
+    float get_nmea_longitude();
+    float get_nmea_latitude();
+    float get_dec_longitude();
+    float get_dec_latitude();
+    float get_msl_altitude();
+    float get_course_t();
+    float get_course_m();
+    float get_speed_k();
+    float get_speed_km();
+    int get_satelites();
+    float get_altitude_ft();
+    
+    // navigational functions
+    float calc_course_to(float, float);
+    double calc_dist_to_mi(float, float);
+    double calc_dist_to_ft(float, float);
+    double calc_dist_to_km(float, float);
+    double calc_dist_to_m(float, float);
+    
+private:
+    float nmea_to_dec(float, char);
+    float trunc(float v);
+    
+    // calculated values
+    volatile float dec_longitude;
+    volatile float dec_latitude;
+    volatile float altitude_ft;
+    
+    // GGA - Global Positioning System Fixed Data
+    volatile float nmea_longitude;
+    volatile float nmea_latitude;    
+    volatile float utc_time;
+    volatile char ns, ew;
+    volatile int lock;
+    volatile int satelites;
+    volatile float hdop;
+    volatile float msl_altitude;
+    volatile char msl_units;
+    
+    // RMC - Recommended Minimmum Specific GNS Data
+    volatile char rmc_status;
+    volatile float speed_k;
+    volatile float course_d;
+    volatile int date;
+    
+    // GLL
+    volatile char gll_status;
+    
+    // VTG - Course over ground, ground speed
+    volatile float course_t; // ground speed true
+    volatile char course_t_unit;
+    volatile float course_m; // magnetic
+    volatile char course_m_unit;
+    volatile char speed_k_unit;
+    volatile float speed_km; // speek km/hr
+    volatile char speed_km_unit;
+};
+
+#endif