USB GPS

[AdRiley]

So I want to make my Pi into a car computer with GPS. Does anyone know if there are any code samples anywhere which pull the latitude and longitude from a USB GPS device?

[Mortimer]

Pretty much all USB GPS devices I have come across have appeared as serial devices. The reason is that GPS receiver chips generally generate a series of what are called "NMEA0183 sentences", which are just text strings. The electrical part of NMEA0183 is a RS422 based bus, but point to point connections of GPS to computer is often supported on RS232. Therefore it is not unusual for USB GPS receivers to simply appear as USB serial converters. I would imagine that finding a driver should be fairly trivial, it is then just a matter of decoding the sentences to extract the information that you want.