gps1_5.c begins by opening a file gpsData.txt which will save all GPS message strings in ASCII. Next, the serial port is opened using a function prototype comm_setting() which invokes functions found in the IBMCOM library.



A while loop is entered, where the statement charRead = com_rx() serially reads a character and checks if it begins with a dollar sign. If so, this indicates a new GPS message string has been received and more characters are read until a carriage return (CR) is found.



tempString holds the GPS message string that was serially read. If it is a $GPGGA message, additional reading is done, where we know that commas separate geospatial data. sscanf is used to extract numerical data from the ASCII characters. -gps1_5.c begins by opening a file gpsData.txt which will save all GPS message strings in ASCII. Next, the serial port is opened using a function prototype comm_setting()　which invokes functions found in the IBMCOM library.



A while loop is entered, where the statement charRead = com_rx()　serially reads a character and checks if it begins with a dollar sign. If so, this indicates a new GPS message string has been received and more characters are read until a carriage return (CR) is found.



tempString holds the GPS message string that was serially read. If it is a $GPGGA message, additional reading is done, where we know that commas separate geospatial data. sscanf is used to extract numerical data from the ASCII characters.