Revision 0:697a7215cc10, committed 2012-10-06

Comitter:

SamClarke

Date:

Sat Oct 06 22:41:59 2012 +0000

Child:

1:0a034c2dbea6

Commit message:

Basic version

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS.cpp	Sat Oct 06 22:41:59 2012 +0000
@@ -0,0 +1,73 @@
+#include "GPS.h"
+
+GPS::GPS(PinName tx, PinName rx) : _UltimateGps(tx, rx)
+{
+    _UltimateGps.baud(9600);
+}
+
+int GPS::parseData()
+{
+
+    while(1) {
+        getData();
+        if(sscanf(NEMA, "GPGGA, %*f, %*f, %*c, %*f, %*c, %d, %d, %*f, %f", &fixtype, &satellites, &altitude) >=1);
+        if(sscanf(NEMA, "GPRMC, %f, %c, %f, %c, %f, %c, %f, %f, %d", &time, &validity, &latitude, &ns, &longitude, &ew, &speed, &heading, &date) >=1) {
+            if(fixtype == '0') {
+                return 0;
+            }
+            if(fixtype == '1') {
+                fixname = "Positive";
+            }
+            if(fixtype == '2') {
+                fixname = "Differential";
+            }
+            if(ns =='S') {
+                latitude   *= -1.0;
+            }
+            if(ew =='W') {
+                longitude  *= -1.0;
+            }
+            float degrees = trunc(latitude / 100.0f);
+            float minutes = latitude - (degrees * 100.0f);
+            latitude = degrees + minutes / 60.0f;
+            degrees = trunc(longitude / 100.0f);
+            minutes = longitude - (degrees * 100.0f);
+            longitude = degrees + minutes / 60.0f;
+            return 1;
+        }
+    }
+}
+
+
+float GPS::trunc(float v)
+{
+    if(v < 0.0) {
+        v*= -1.0;
+        v = floor(v);
+        v*=-1.0;
+    } else {
+        v = floor(v);
+    }
+    return v;
+}
+
+void GPS::getData()
+{
+    while(_UltimateGps.getc() != '$');
+    for(int i=0; i<256; i++) {
+        NEMA[i] = _UltimateGps.getc();
+        if(NEMA[i] == '\r') {
+            NEMA[i] = 0;
+            return;
+        }
+    }
+    error("overflowed message limit");
+}
+
+void GPS::Init()
+{
+    _UltimateGps.printf("$PMTK220,1000*1F\r\n");
+    wait(1);
+    _UltimateGps.printf("$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n");
+    wait(1);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS.h	Sat Oct 06 22:41:59 2012 +0000
@@ -0,0 +1,63 @@
+/******************************************************
+* A basic mbed library for the Adafruit ultimate      *
+* GPS module NOTE: the LOCUS functions are yet to be  *
+* implemented                                         *
+*                                                     *
+*                              Written by: Sam Clarke *
+******************************************************/
+
+#include "mbed.h"
+#include <string>
+
+#ifndef GPS_H
+#define GPS_H
+
+// EXAMPLE OUTPUTS
+//
+// $GPRMC,064951.000,A,2307.1256,N,12016.4438,E,0.03,165.48,260406,3.05,W,A*2C
+// $GPRMC, time, status, latitude, N/S, longitude, E/W, speed(knots), heading, date, N/A, N/A, MODE*CHECKSUM
+//
+// $GPGGA,064951.000,2307.1256,N,12016.4438,E,1,8,0.95,39.9,M,17.8,M,,*65
+// $GPGGA, time, latitude, N/S, longitude, E/W, fix, satellites, hdop, altitude, M, geoidal sep , M,,*CHECKSUM
+// $GPGGA, %f, %*f, %*c, %*f, %*c, %d, %d, %*f, %*f, %*c, %*f , %*c,,%*c%*c%*c0
+
+class GPS
+{
+public:
+
+    GPS(PinName tx, PinName rx);
+    void Init();
+    int parseData();
+    float time;         // UTC time
+    char validity,ns,ew;// RMC data status A = Data Valid; V = Data Not valid;
+    float latitude;     //
+    float longitude;    //
+    float speed;        // speed in knots
+    float heading;      // heading in degrees derived from previous & current location
+    int date;           //
+    int fixtype;        // 0 = no fix;  1 = fix;  2=differential fix
+    int satellites;     // number of satellites used
+    float altitude;     //
+    string fixname;
+
+private:
+
+    float trunc ( float v);
+    void getData();
+    Serial _UltimateGps;
+    char NEMA[256];
+    string posfix;
+    string diffix;
+
+};
+#endif
+
+/*
+#define 1HZ_STREAM  "$PMTK220,1000*1F\r\n"  // 1.0 second interval
+#define 5HZ_STREAM  "$PMTK220,200*2C\r\n"   // 0.2 second interval
+#define 10HZ_STREAM "$PMTK220,100*2F\r\n"   // 0.1 second interval
+
+#define OUTPUT_RMC    "$PMTK314,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29\r\n"
+#define OUTPUT_RMCGGA "$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"
+#define OUTPUT_OFF    "$PMTK314,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28\r\n"
+*/
\ No newline at end of file