Patrick Cooney's Weblog

GPS Code

2008-06-25

As promised, here is source code for reading GPS data from the Streets and Trips USB GPS on OS X. This is the most C code I have written in a while, so don't go putting it into production!

Here's how it works:

nmea.h/.c - Structs representing nmea data, and code for reading data from the serial port, and parsing this out of a comma separated string. I have restricted myself to only parsing bits of the gga sentence, but it would be straightforward to extend this to other data and sentences.

serial.h/.c - Code for opening and closing the serial port.

main.c - A small main method that reads the nmea data and prints the lat, long and altitude to the console.

If you want to try it out, don't forget to install the serial port driver as described in my previous post. Have fun with it!

Tags: programming

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