We want to avoid using doubles where unnessesary since many embedded
targets have only a single precision FPU or no FPU at all.
Passing doubles is unavoidable with the printf family of functions,
so use an explicit cast to silence the warning.
Not sure whether to make it float or double by default
/*************************************************************************
doubles and floats are identical on AVR processors like the UNO where space
is tight. doubles avoid the roundoff errors that led to the fixed point mods
in https://github.com/adafruit/Adafruit-GPS-Library/pull/13, provided the
processor supports actual doubles like the SAMD series with more storage. The
total penalty for going all double is under a few hundred bytes / instance or
0 bytes / instance on an UNO. This typedef allows a switch to lower precision
to save some storage if needed. A float carries 23 bits of fractional
resolution, giving a resolution of at least 9 significant digits, thus 6
significant digits in the decimal place of an angular value like latitude, and
thus a resolution on earth of at least 110 mm. That's closer than GPS will
hit, and closer than needed for navigation, so floats can be used to save a
little storage.
**************************************************************************/
typedef double
nmea_float_t; ///< the type of variables to use for floating point
Rick Sellens
Owen Torres