gnss

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GNSS click

GNSS click carries Quectel’s L86 GNSS module with a patch antenna along with an external antenna connector.

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Click library

• Author : Stefan Filipovic
• Date : Jul 2022.
• Type : UART type

Software Support

We provide a library for the GNSS Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for GNSS Click driver.

Standard key functions :

• gnss_cfg_setup Config Object Initialization function.

void gnss_cfg_setup ( gnss_cfg_t *cfg );

• gnss_init Initialization function.

err_t gnss_init ( gnss_t *ctx, gnss_cfg_t *cfg );

Example key functions :

• gnss_generic_read This function reads a desired number of data bytes by using UART serial interface.

err_t gnss_generic_read ( gnss_t *ctx, char *data_out, uint16_t len );

• gnss_clear_ring_buffers This function clears UART tx and rx ring buffers.

void gnss_clear_ring_buffers ( gnss_t *ctx );

• gnss_parse_gpgga This function parses the GPGGA data from the read response buffer.

err_t gnss_parse_gpgga ( char *rsp_buf, uint8_t gpgga_element, char *element_data );

Example Description

This example demonstrates the use of GNSS click by reading and displaying the GPS coordinates.

The demo application is composed of two sections :

Application Init

Initializes the driver and logger.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    gnss_cfg_t gnss_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.
    gnss_cfg_setup( &gnss_cfg );
    GNSS_MAP_MIKROBUS( gnss_cfg, MIKROBUS_1 );
    if ( UART_ERROR == gnss_init( &gnss, &gnss_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    log_info( &logger, " Application Task " );
}

Application Task

Reads the received data, parses the GPGGA info from it, and once it receives the position fix it will start displaying the coordinates on the USB UART.

void application_task ( void )
{
    if ( GNSS_OK == gnss_process( &gnss ) )
    {
        if ( PROCESS_BUFFER_SIZE == app_buf_len )
        {
            gnss_parser_application( &gnss, app_buf );
        }
    }
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.GNSS

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. UART terminal is available in all MikroElektronika compilers.

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