Diff: nmea_parser.h

Revision:

9:9b2351e25a84

Parent:

8:59acef1c795b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nmea_parser.h	Mon Dec 17 22:11:24 2012 +0000
@@ -0,0 +1,176 @@
+/*
+ * @file nmea_parser.h
+ * @author Tyler Weaver
+ *
+ * @section LICENSE
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * @section DESCRIPTION
+ *
+ * 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
+ */
+
+#include "mbed.h"
+
+#ifndef MBED_NMEA_PARSER_H
+#define MBED_NMEA_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 NmeaParser interface for parsing NMEA gps serial output */
+class NmeaParser
+{
+public:
+
+    /**
+    * Default Constructor
+    * Initalizes variables
+    */
+    NmeaParser();
+
+    /** Parse the incoming GPS data, returning whether there is a lock
+     *
+     * Routine from NMEA Software Standard (NMEA 0183)
+     *
+     * @param line the nmea string to parse, uses tokenizer vs sscanf 
+     * @return 1 if there was a lock when the sample was taken (and therefore .longitude and .latitude are valid), else 0
+     */
+    int parse(char *);
+    
+    /**
+    * @returns quality of signal (0 = No GPS, 1 = GPS, 2 = DGPS)
+    */
+    int quality();
+    /**
+    * From RMC message
+    * @returns date in ddmmyy format
+    */
+    int date();
+    /**
+    * @returns time in utc format hhmmss.ss format
+    */
+    float utc_time();
+    /**
+    * @returns Longitude in NMEA format dddmm.mm
+    */
+    float longitude();
+    /**
+    * @returns Latitude in NMEA format dddmm.mm
+    */
+    float latitude();
+    /**
+    * @returns Altitude Mean Sea Level (MSL) in Meters
+    */
+    float msl_altitude();
+    /**
+    * @returns track (heading) made good in degrees true.
+    */
+    float track();
+    /**
+    * @returns speed over ground in knots
+    */
+    float speed();
+    /**
+    * @returns number of satellites in use
+    */
+    int satellite_count();
+
+    /**
+    * @returns longitude in decimal form (calculated)
+    */
+    float calc_dec_longitude();
+    /**
+    * @returns longitude in decimal form (calculated)
+    */
+    float calc_dec_latitude();
+    /**
+    * @returns altitude MSL in feet (calculated)
+    */
+    float calc_altitude_ft();
+    /**
+    * Initial bearing is the angle to fly at for the shortest flight between two points on a sphere.
+    * Calculations from: http://www.movable-type.co.uk/scripts/latlong.html
+    *
+    * Uses current position and calculates to the inputed point.
+    *
+    * @param latitude of target point
+    * @param longitude of target point
+    * @returns initial bearing for flying to given point
+    */
+    float calc_initial_bearing(float, float);
+    /**
+    * Uses the shortest distance across a sphere (haversine formula) to calculate distance
+    *
+    * Uses current position and calculates to the inputed point.
+    *
+    * @param latitude of target point
+    * @param longitude of target point
+    * @returns distance in miles to given point
+    */
+    double calc_dist_to_mi(float, float);
+    /**
+    * Uses the calc_dist_to_mi then converts to kilometers.
+    *
+    * @param latitude of target point
+    * @param longitude of target point
+    * @returns distance in kilometers to given point
+    */
+    double calc_dist_to_km(float, float);
+private:
+    float nmea_to_dec(float, char);
+    char *my_token(char *,char);
+
+    char stat_string_[128]; // used in my_token
+    char *current_;
+    
+    char *field_[50]; // used by parse nmea
+
+    // calculated values
+    volatile float dec_longitude_;
+    volatile float dec_latitude_;
+
+    // GGA - Global Positioning System Fixed Data
+    volatile float utc_time_;
+    volatile float latitude_;
+    volatile char lat_reference_;
+    volatile float longitude_;
+    volatile char long_reference_;
+    volatile int quality_;
+    volatile int satellite_count_;
+    volatile float hdop_;
+    volatile float msl_altitude_;
+    volatile char msl_altitude_unit_;
+
+    // RMC - Recommended Minimmum Specific GNS Data
+    volatile char rmc_status_;
+    volatile float speed_;
+    volatile float track_;
+    volatile int date_;
+};
+
+#endif