GPSBabel: convert, manipulate, and transfer data from GPS programs or GPS receivers. Open Source and supported on MacOS, Windows, Linux, and more. Pointy clicky GUI or a command line version...
It appears the GSR80 value was used instead of the WGS84 value, which is a very small error.
However, there was a typo in the value in GPS_Math_XYZ_To_WGS84LatLonH that resulted in an order of magnitude error!
This could lead to GPS_Math_XYZ_To_WGS84LatLonH never converging. This may be why skytraq created their own function to convert ECEF to WGS84.
It appears the GSR80 value was used instead of the WGS84 value, which is a very small error. However, there was a typo in the value in GPS_Math_XYZ_To_WGS84LatLonH that resulted in an order of magnitude error! This could lead to GPS_Math_XYZ_To_WGS84LatLonH never converging. This may be why skytraq created their own function to convert ECEF to WGS84.