christian b / GPS

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:
1:fade122a76a8
Parent:
0:0c1aa5906cef
Child:
2:72ac4d7044a7
diff -r 0c1aa5906cef -r fade122a76a8 utils/GPSUtils.hpp
--- a/utils/GPSUtils.hpp	Wed Aug 06 01:37:39 2014 +0000
+++ b/utils/GPSUtils.hpp	Mon Apr 06 17:41:43 2015 +0000
@@ -81,4 +81,20 @@
     }
     return decimal;
 }
+
+// Coverts ECEF to ENU coordinates centered at given lat, lon
+void ecefToEnu(double lat, double lon, double x, double y, double z, double xr, double yr, double zr, double *e, double *n, double *u)
+{
+    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 dx = x - xr;
+    double dy = y - yr;
+    double dz = z - zr;
+
+    *e = -slon*dx  + clon*dy;
+    *n = -slat*clon*dx - slat*slon*dy + clat*dz;
+    *u = clat*clon*dx + clat*slon*dy + slat*dz;
+}
 #endif
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