christian b
Mbed library to handle GPS data reception and parsing
Dependents: GPS_U-blox_NEO-6M_Code
Features
- All positionning parameters are contained into a global data structure.
- Automatic nema string parsing and data structure update.
- GSA,GGA,VTG and RMC
- Convert latitude and longitude to decimal value.
- Converts latittude,longitude and altitude to ECEF coordinates.
Planed developement
- Test library for RTOS use.
- Complete the nema parsing decoders (couple of parameters are not parsed yet and not present in the data structure).
- Add conversion tool to get ENU coordinates.
Diff: utils/GPSUtils.hpp
- Revision:
- 0:0c1aa5906cef
- Child:
- 1:fade122a76a8
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/utils/GPSUtils.hpp Wed Aug 06 01:37:39 2014 +0000
@@ -0,0 +1,84 @@
+#ifndef _GPSUTILS_H_
+#define _GPSUTILS_H_
+
+#include "mbedGPSDefs.h"
+#include "GPGGAdecoder.hpp"
+#include "GPVTGdecoder.hpp"
+#include "GPGSAdecoder.hpp"
+#include "GPRMCdecoder.hpp"
+#include "WGS84.h"
+
+#define PI 3.141592653589793238462643383279502884
+#define RADIANS_TO_DEGREES(radians) ((radians) * (180.0 / PI))
+#define DEGREES_TO_RADIANS ( PI / 180.0)
+#define WGS84_A 6378137.000
+//298.257223563
+#define WGS84_E 0.081819190842621
+
+
+/*
+ Source of information about nema sentences :
+ http://www.gpsinformation.org/dale/nmea.htm
+*/
+void DecodeMessage(message& msg,GPSInfo& data)
+{
+
+ if(strstr(msg.data,GPS_CMD_GPGGA)){
+ DecodeGPGGA(msg.data,data);
+ }
+
+ if(strstr(msg.data,GPS_CMD_GPVTG)){
+ DecodeGPVTG(msg.data,data);
+ }
+
+ if(strstr(msg.data,GPS_CMD_GPGSA)){
+ DecodeGPGSA(msg.data,data);
+ }
+ if(strstr(msg.data,GPS_CMD_GPRMC)){
+ DecodeGPRMC(msg.data,data);
+ }
+}
+
+ECEFPoint GeoDesicToECEF(geodPoint p)
+{
+ ECEFPoint newECEFpoint;
+ double lat = 0.0;
+ double lon = 0.0;
+ lat = p.latitude;
+ lon = p.longitude;
+
+ double clat = cos(lat * DEGREES_TO_RADIANS);
+ double slat = sin(lat * DEGREES_TO_RADIANS);
+ double clon = cos(lon * DEGREES_TO_RADIANS);
+ double slon = sin(lon * DEGREES_TO_RADIANS);
+
+ double N = WGS84_A / sqrt(1.0 - WGS84_E * WGS84_E * slat * slat);
+
+ newECEFpoint.x = (N + p.altitude) * clat * clon;
+ newECEFpoint.y = (N + p.altitude) * clat * slon;
+ newECEFpoint.z = (N * (1.0 - WGS84_E * WGS84_E) + p.altitude) * slat;
+
+ return newECEFpoint;
+}
+
+ECEFDistance DistanceBetweenTwoECEFPoints(ECEFPoint p1, ECEFPoint p2)
+{
+ ECEFDistance newDistance;
+ newDistance.dx = p1.x-p2.x;
+ newDistance.dy = p1.y-p2.y;
+ newDistance.dz = p1.z-p2.z;
+ newDistance.d = sqrt((newDistance.dx*newDistance.dx) + (newDistance.dy*newDistance.dy) + (newDistance.dz*newDistance.dz));
+ return newDistance;
+}
+
+float nmea_to_dec(double nema_coor, char nsew) {
+ int degree = (int)(nema_coor/100);
+ double minutes = nema_coor - degree*100;
+ double dec_deg = minutes / 60;
+ double decimal = degree + dec_deg;
+ if (nsew == 'S' || nsew == 'W') { // return negative
+ decimal *= -1;
+ }
+ return decimal;
+}
+#endif
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