Revision 0:94c22ada3c5a, committed 2012-07-01

Comitter:

JST2011

Date:

Sun Jul 01 15:14:45 2012 +0000

Commit message:

*Fixed calculation around longitude

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS.cpp	Sun Jul 01 15:14:45 2012 +0000
@@ -0,0 +1,92 @@
+#include "GPS.h"
+
+GPS::GPS(PinName tx, PinName rx) : _gps(tx, rx) {
+    _gps.baud(4800);
+    _gps.printf("$PSRF103,2,0,0,1*26\r\n");
+    _gps.printf("$PSRF103,3,0,0,1*27\r\n");
+    _gps.printf("$PSRF103,4,0,0,1*20\r\n");
+    flag_gps_get = 0;
+    flag_gps_getend = 0;
+    _gps.attach(this,&GPS::sample,Serial::RxIrq);
+    count = 0;
+    flag_gga = 0;
+}
+
+void GPS::sample() {
+    getline();
+    if(flag_gps_getend){
+        if(sscanf(msg, "$GPGGA,%f,%f,%c,%f,%c,%d", &_time, &_latitude, &_ns, &_longitude, &_ew, &_lock) >= 1) {
+            flag_gga = 1;
+            strcpy(gga,msg);
+            float degrees = floor(_latitude / 100.0f);
+            float minutes = _latitude - (degrees * 100.0f);
+            _latitude = degrees + minutes / 60.0f;
+            degrees = floor(_longitude / 100.0f);
+            minutes = _longitude - (degrees * 100.0f);
+            _longitude = degrees + minutes /60.0f;
+        }
+        flag_gps_getend = 0;
+    }
+}
+
+char* GPS::getGGA(){
+    if(flag_gga){
+//        strcpy(gga,msg);
+        flag_gga = 0;
+    }
+    return gga;
+}
+
+float GPS::longitude(){
+    return _longitude;
+}
+
+float GPS::latitude(){
+    return _latitude;
+}
+
+float GPS::time(){
+    return _time;
+}
+
+int GPS::ns(){
+    int d;
+    if(_ns == 'N'){
+        d = 1;
+    }else{
+        d = -1;
+    }
+    return d;
+}
+
+int GPS::ew(){
+    int d;
+    if(_ew == 'E'){
+        d = 1;
+    }else{
+        d = -1;
+    }
+    return d;
+}
+
+int GPS::lock(){
+    return _lock;
+}
+
+void GPS::getline() {
+    char temp;
+    temp = _gps.getc();
+    if(temp == '$'){
+        flag_gps_get = 1;
+        count = 0;
+    }
+    if(flag_gps_get){
+        msg[count] = temp;
+        if(temp == '\r'){
+            msg[count] = '\0';
+            flag_gps_getend = 1;
+            flag_gps_get = 0;
+        }
+        count ++;
+    }
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/GPS.h	Sun Jul 01 15:14:45 2012 +0000
@@ -0,0 +1,29 @@
+#include "mbed.h"
+#ifndef MBED_GPS_H
+#define MBED_GPS_H
+class GPS {
+public:
+    GPS(PinName tx, PinName rx);
+    char* getGGA();
+    float longitude();
+    float latitude();
+    float time();
+    int ns();
+    int ew();
+    int lock();
+private:
+    void sample();
+    void getline();
+    Serial _gps;
+    char msg[128],gga[128];
+    float _longitude;
+    float _latitude;
+    float _time;
+    char _ns, _ew;
+    int _lock;
+    int flag_gps_get;
+    int flag_gps_getend;
+    int count;
+    int flag_gga;
+};
+#endif
\ No newline at end of file