// $GPRMC,HHMMSS,A,DDMM.MMM,N,DDDMM.MMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E*XX
sprintf( rmc, "GPRMC,%s,A,%s,%s,%s,%s,%s,0.000,E",
utc, lat, lon, speed, heading, date );
// $GPRMC,HHMMSS,A,DDMM.MMM,N,DDDMM.MMM,W,XXX.X,XXX.X,DDMMYY,XXX.X,E*XX
sprintf( rmc, "GPRMC,%s,A,%s,%s,%s,%s,%s,0.000,E",
utc, lat, lon, speed, heading, date );