Library Description

Library carries generic command parser adopted for GPS-MNEA command based modules. Generic parser

Key functions:

• gnss7_cmdSingle - Sends provided command to the module
• gnss7_setHandle - Handler assignation to the provied command
• gnss7_modulePower - Turn on module

Examples description

The application is composed of three sections :

• System Initialization - Initializes all necessary GPIO pins, UART used for the communcation with GSM module and UART used for infromation logging
• Application Initialization
• Initializes driver, power on module and sends few command for the default module configuration
• Application Task - running in parallel core state machine and checks for call flag. If call detected parser will hang up call.

void application_task ( )
{
    char *p_lat;
    char *p_long;
    char *p_alt;
    char rsp_com[ 50 ] = {0};

    gnss7_process( );

    if ( timer_cnt > 5000 )
    {
        p_flag++;
        if ( p_flag > 2 )
        {
            p_flag = 0;
        }
        timer_cnt = 0;
        disp_flag = 1;
    }

    if ( ( p_flag == 0 ) && ( disp_flag == 1) )
    {
        mikrobus_logWrite( " ---------------------------------------- ", _LOG_LINE );
        p_lat = gnss7_gps_parser( &demo_buf[ 0 ], &demo_cmd[ 0 ], 2 );

        if ( p_lat == 0 )
        {
            mikrobus_logWrite( " Latitude : No data available!", _LOG_LINE );
        }
        else
        {
            strcpy( &rsp_com[ 0 ], p_lat );
            mikrobus_logWrite( " Latitude : ", _LOG_TEXT );
            mikrobus_logWrite( rsp_com, _LOG_LINE );
        }
        disp_flag = 0;
        mikrobus_logWrite( " ---------------------------------------- ", _LOG_LINE );
    }

    if ( ( p_flag == 2 ) && ( disp_flag == 1) )
    {
        mikrobus_logWrite( " ---------------------------------------- ", _LOG_LINE );
        p_alt = gnss7_gps_parser( &demo_buf[ 0 ], &demo_cmd[ 0 ], 9 );
        if ( p_alt == 0 )
        {
            mikrobus_logWrite( " Altitude : No data available!", _LOG_LINE );
        }
        else
        {
            strcpy( &rsp_com[ 0 ], p_alt );
            mikrobus_logWrite( " Altitude : ", _LOG_TEXT );
            mikrobus_logWrite( rsp_com, _LOG_LINE );
        }
        disp_flag = 0;
        mikrobus_logWrite( " ---------------------------------------- ", _LOG_LINE );
    }

    if ( ( p_flag == 1 ) && ( disp_flag == 1 ) )
    {
        mikrobus_logWrite( " ---------------------------------------- ", _LOG_LINE );
        p_long = gnss7_gps_parser( &demo_buf[ 0 ], &demo_cmd[ 0 ], 4 );
        if ( p_long == 0 )
        {
            mikrobus_logWrite( " Longitude : No data available!", _LOG_LINE );
        }
        else
        {
            strcpy( &rsp_com[ 0 ], p_long );
            mikrobus_logWrite( " Longitude : ", _LOG_TEXT );
            mikrobus_logWrite( rsp_com, _LOG_LINE );
        }
        disp_flag = 0;
        mikrobus_logWrite( " ---------------------------------------- ", _LOG_LINE );
    }
}

All additional functions such as timer initialization and default handler.

Notes GPS:

• The GPS module returns data in the form of NMEA responses
• For example, we used the GGA response

For parsing, use the GPS Parser function to send the following form of arguments: The name of the NMEA response that you want to parse, the position of the data that you need. As a response - you will get a separate buffer with the requested data

Other mikroE Libraries used in the example:

• UART
• String
• Conversions

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.