Using this free tool you can create NMEA log with valid CRC. Generated NMEA-0183 version: 2.0 compatible. Created NMEA message types: RMC, GGA, GLL, FSA, GSV, VTG, ZDA
This page generates example of NMEA log file. Current UTC time is used for the first sentence, next sentences are simulated one per second, i.e. it simulates GPS with 1 Hz NMEA.