GNSS RTK 3 click

GNSS RTK 3 Click is a compact add-on board that enhances the precision of position data derived from satellite-based positioning systems. This board features the LC29H, a dual-band, multi-castellation GNSS module from Quectel. This module supports the concurrent reception of all five global GNSS constellations: GPS, BDS, Galileo, GZSS, and GLONASS. It can receive and track many visible satellites in multi-bands, significantly mitigating the multipath effect in deep urban canyons and improving positioning accuracy.

click Product page

Click library

• Author : Stefan Filipovic
• Date : Sep 2023.
• Type : UART/I2C type

Software Support

We provide a library for the GNSS RTK 3 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 RTK 3 Click driver.

Standard key functions :

• gnssrtk3_cfg_setup Config Object Initialization function.

  void gnssrtk3_cfg_setup ( gnssrtk3_cfg_t *cfg );

• gnssrtk3_init Initialization function.

  err_t gnssrtk3_init ( gnssrtk3_t *ctx, gnssrtk3_cfg_t *cfg );

Example key functions :

• gnssrtk3_enable_device This function enables the device by setting the CEN pin to high logic state.

  void gnssrtk3_enable_device ( gnssrtk3_t *ctx );

• gnssrtk3_generic_read This function reads a desired number of data bytes by using UART or I2C serial interface.

  err_t gnssrtk3_generic_read ( gnssrtk3_t *ctx, uint8_t *data_out, uint16_t len );

• gnssrtk3_parse_gga This function parses the GGA data from the read response buffer.

  err_t gnssrtk3_parse_gga ( uint8_t *rsp_buf, uint8_t gga_element, uint8_t *element_data );

Example Description

This example demonstrates the use of GNSS RTK 3 click by reading and displaying the GNSS coordinates.

The demo application is composed of two sections :

Application Init

Initializes the driver and enables the click board.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    gnssrtk3_cfg_t gnssrtk3_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.
    gnssrtk3_cfg_setup( &gnssrtk3_cfg );
    GNSSRTK3_MAP_MIKROBUS( gnssrtk3_cfg, MIKROBUS_1 );
    if ( GNSSRTK3_OK != gnssrtk3_init( &gnssrtk3, &gnssrtk3_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    gnssrtk3_enable_device ( &gnssrtk3 );

    log_info( &logger, " Application Task " );
}

Application Task

Reads the received data, parses the NMEA GGA 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 ( GNSSRTK3_OK == gnssrtk3_process( &gnssrtk3 ) ) 
    {
        gnssrtk3_parser_application( 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.GNSSRTK3

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.