Pre-Notes: Library is customizable in size.  With all features enabled, library compiles to ~14kb.  To customize the size, comment or un-comment out sentences in the gps_config.h file. Usage Scenario:

1. GPS data coming over i2c, uart, or spi
2. Need specific information from GPS

How to: Set up gps data for parsing. 

Example:

#include "gps_parser.h"

void system_init()
{    
    ...    
    UART1_Init_Advanced(115200, _UART_8_BIT_DATA, _UART_NOPARITY,
    _UART_ONE_STOPBIT, &_GPIO_MODULE_USART1_PA9_10);
    Delay_ms( 100 ); // Allow a small delay for clock stability    
    RXNEIE_USART1_CR1_bit = 1; // Enable rx interrupt for usart 1    
    NVIC_IntEnable( IVT_INT_USART1 ); // Enable NVIC for rx usart1 interrupt    
    ….
}  

void main()
{    
    system_init();      
    while( 1 )    
    {        
        gps_parse();    
    }
}  

void UART1_RX_ISR() iv IVT_INT_USART1 ics ICS_AUTO
{    
    if( RXNE_USART1_SR_bit )    
    {        
        gps_put( USART1_DR );      
    }
}  

Explaination: What we have done is connected up a usart to a gps. When data comes from the gps it triggers the interrupt which places the incoming data into the gps_put() function. Meanwhile in the main loop we are repeatedly calling gps_parse(); When this function receives a full sentence, it quickly parses it into the respective data. The gps_put() function can also be put into a pooling loop as well.

while(1)
{    
    …    
    if( UART1_Data() )    
    {        
        gps_put( UART1_Read() );    
    }    
    gps_parse();
}

So what does this do? What it gives you access to is the following functions:

• location_t * gps_current_lon (void)
• location_t * gps_current_lat (void)
• TimeStruct * gps_current_time (void)
• utc_time_t * gps_current_fix (void)
• fix_t gps_gga_fix_quality (void)
• uint8_t gps_gga_satcount (void)
• float gps_gga_hor_dilution (void)
• double gps_gga_altitude (void)
• double gps_gga_msl (void)
• uint16_t gps_gga_lastDGPS_update (void)
• uint16_t gps_gga_DGPS_stationID (void)
• ACTIVE_t gps_gll_active (void)
• GSA_MODE_t gps_gsa_mode (void)
• GSA_MODE_t gps_gsa_fix_type (void)
• uint8_t * gps_gsa_sat_prn (void)
• float gps_gsa_precision_dilution (void)
• float gps_gsa_horizontal_dilution (void)
• float gps_gsa_vertical_dilution (void)
• GPS_STATUS_t gps_rmc_status (void)
• double gps_rmc_speed (void)
• double gps_rmc_track (void)
• double gps_rmc_mag_var (void)
• azmuth_t gps_rmc_direction (void)
• GPS_STATUS_t gps_rmc_mode (void)
• double gps_vtg_track (void)
• double gps_vtg_mag (void)
• double gps_vtg_speedknt (void)
• double gps_vtg_speedkm (void)
• datum_code_t gps_dtm_local (void)
• char * gps_dtm_localoffset (void)
• double gps_dtm_latoffset (void)
• azmuth_t gps_dtm_lat_offset_dir (void)
• double gps_dtm_lonoffset (void)
• azmuth_t gps_dtm_lon_offset_dir (void)
• double gps_dtm_altoffset (void)
• datum_code_t gps_dtm_datum (void)
• float gps_gbs_laterror (void)
• float gps_gbs_lonerror (void)
• float gps_gbs_alterror (void)
• uint8_t gps_gbs_satid (void)
• float gps_gbs_probmiss (void)
• double gps_gbs_failedest (void)
• float gps_gbs_std_deviation (void)
• char * gps_gpq_message (void)
• uint8_t gps_grs_mode (void)
• float gps_grs_range (void)
• float gps_gst_rms (void)
• float gps_gst_stddev_major (void)
• float gps_gst_stddev_minor (void)
• float gps_gst_orientation (void)
• float gps_gst_stddev_lat (void)
• float gps_gst_stddev_lon (void)
• float gps_gst_stddev_alt (void)
• double gps_ths_heading (void)
• vehicle_status_t gps_ths_status (void)

Note*

When changing the configuration of the library. You will need to re-build all sources to re-compile the library for the new / fewer features as described in gps_config.h.