Beginner
10 min

Experience navigation like never before with L86 and PIC18F57Q43

Get lost in an adventure, not in navigation

GNSS Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

GNSS Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Take control of your journey and build a custom navigation system that suits all your needs

A

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Hardware Overview

How does it work?

GNSS Click is based on the L86, a compact GNSS module from Quectel Wireless Solutions. The L86 supports the L1 band only (1575.42MHz for GPS and 1601.71MHz for GLONASS), with 33 tracking and 99 acquisition channels. Under L86's hood is the MediaTek MT3333 chipset that can achieve the perfect performance. The module is an ultra-low tracking power consumption device with a high sensitivity of -167dBm while tracking and -149dBm in acquisition mode with a reacquisition time of less than 1 second. The greater number of visible satellites increases horizontal positioning accuracy (<2.5m CEP) and decreases acquisition time (<5s TTFF with a warm start). GNSS Click supports anti-jamming and better positioning under signal conditions with onboard LNA for better sensitivity, multi-tone active interference canceller, and balloon mode for high altitudes up to 80km. The L86 can automatically predict satellite orbits from data stored in its internal flash (EASY™ technology). Also, it can adaptively adjust its ON/OFF time to balance positioning accuracy

and power consumption (AlwaysLocate™ technology). To save power consumption, GNSS Click comes with VBAT connection pads and a backup power supply selection jumper for connecting an external power supply that can supply power to the module's SRAM memory. This memory serves for storing GPS information for quick Start-Up sequences. Periodic Standby mode can periodically control the board's power on/off time to reduce average power consumption, configurable using the PMTK command. GNSS Click will enter the Periodic mode after successfully fixing the position. For communication with the host microcontroller, L86 uses the UART interface with commonly used UART RX and TX pins as its default communication protocol operating at 9600bps by default configuration to transmit and exchange data. In addition, the Click board™ features other functions accessible through mikroBUS™ signals, such as Force on (FON) and Reset (RST). A logic high state on the FON pin will force the module to

wake from Backup mode, while the RST pin provides a general reset function. In addition to the possibility of using the built-in POT antenna, this Click board™ can also use an external active antenna offered by Mikroe, thanks to the onboard u.FL connector. In addition to precise positioning, the GNSS Click has an accurate timing signal indicated via a red LED indicator marked as PPS and an AADET LED, which serves as an active antenna detection indicator. In addition to the indicator, the NMEA message will include the detection result and notification of different external active antenna statuses. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

GNSS Click hardware overview image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
PA7
RST
Wake Up
PD4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
UART TX
PC2
TX
UART RX
PC3
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

GNSS Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Barometer 13 Click front image hardware assembly
PIC18F57Q43 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Curiosity Nano with PICXXX MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
PIC18F57Q43 Curiosity MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output via UART Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for GNSS Click driver.

Key functions:

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

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

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

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * \file 
 * \brief Gnss Click example
 * 
 * # Description
 * This example reads and processes data from GNSS clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes driver and wake-up module.
 * 
 * ## Application Task  
 * Reads the received data and parses it.
 * 
 * ## Additional Function
 * - gnss_process ( ) - The general process of collecting data the module sends.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "gnss.h"
#include "string.h"

#define PROCESS_COUNTER 15
#define PROCESS_RX_BUFFER_SIZE 600
#define PROCESS_PARSER_BUFFER_SIZE 600

// ------------------------------------------------------------------ VARIABLES

static gnss_t gnss;
static log_t logger;

static char current_parser_buf[ PROCESS_PARSER_BUFFER_SIZE ];

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

static void gnss_process ( void )
{
    int32_t rsp_size;
    uint16_t rsp_cnt = 0;
    
    char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    uint16_t check_buf_cnt;
    uint8_t process_cnt = PROCESS_COUNTER;
    
    // Clear parser buffer
    memset( current_parser_buf, 0 , PROCESS_PARSER_BUFFER_SIZE ); 
    
    while( process_cnt != 0 )
    {
        rsp_size = gnss_generic_read( &gnss, &uart_rx_buffer, PROCESS_RX_BUFFER_SIZE );
       
        if ( rsp_size > 0 ) 
        {  
            // Validation of the received data
            for ( check_buf_cnt = 0; check_buf_cnt < rsp_size; check_buf_cnt++ )
            {
                if ( uart_rx_buffer[ check_buf_cnt ] == 0 ) 
                {
                    uart_rx_buffer[ check_buf_cnt ] = 13;
                }
                
            }
            
           // Storages data in parser buffer
            rsp_cnt += rsp_size;
            if ( rsp_cnt < PROCESS_PARSER_BUFFER_SIZE )
            {
                strncat( current_parser_buf, uart_rx_buffer, rsp_size );
            }
            
            // Clear RX buffer
            memset( uart_rx_buffer, 0, PROCESS_RX_BUFFER_SIZE );
        } 
        else 
        {
            process_cnt--;
            
            // Process delay 
            Delay_ms( 100 );
        }
    }
}

static void parser_application ( char *rsp )
{
    char element_buf[ 200 ] = { 0 };
    
    log_printf( &logger, "\r\n-----------------------\r\n" ); 
    gnss_generic_parser( rsp, GNSS_NEMA_GPGGA, GNSS_GPGGA_LATITUDE, element_buf );
    if ( strlen( element_buf ) > 0 )
    {
        log_printf( &logger, "Latitude:  %.2s degrees, %s minutes \r\n", element_buf, &element_buf[ 2 ] );
        gnss_generic_parser( rsp, GNSS_NEMA_GPGGA, GNSS_GPGGA_LONGITUDE, element_buf );
        log_printf( &logger, "Longitude:  %.3s degrees, %s minutes \r\n", element_buf, &element_buf[ 3 ] );
        memset( element_buf, 0, sizeof( element_buf ) );
        gnss_generic_parser( rsp, GNSS_NEMA_GPGGA, GNSS_GPGGA_ALTITUDE, element_buf );
        log_printf( &logger, "Alitude: %s m", element_buf );  
    }
    else
    {
        log_printf( &logger, "Waiting for the position fix..." );
    }
}

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    gnss_cfg_t cfg;

    /** 
     * 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( &cfg );
    GNSS_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    gnss_init( &gnss, &cfg );

    gnss_module_wakeup( &gnss );
   
    Delay_ms( 5000 );
}

void application_task ( void )
{
    gnss_process(  );
    parser_application( current_parser_buf );
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}


// ------------------------------------------------------------------------ END

Additional Support

Resources

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