How do I use GPS device connected over serial port as a time source in Windows 7?
I have a GPS receiver on my mobile phone which sends data using Bluetooth serial link in NMEA format to computer.
All of the following NMEA sentences contain UTC time
$GPZDA $GPRMC $GPGGA
$GPZDA is best because it is designed to tell the time.
The others can be off +- a couple of seconds.