Beginner
10 min

Navigate with confidence using SIM33ELA and ATmega328

Get lost in adventure, not directions

GNSS 3 Click with Arduino UNO Rev3

Published Feb 14, 2024

Click board™

GNSS 3 Click

Dev Board

Arduino UNO Rev3

Compiler

NECTO Studio

MCU

ATmega328

Our advanced GNSS solution supports navigation, mapping, and geographic analysis by providing real-time positioning data, enhancing decision-making and productivity

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Hardware Overview

How does it work?

GNSS 3 Click is based on the SIM33ELA module, a standalone or A-GPS receiver with a built-in chip antenna from SIMCom. The SIM33ELA supports only the L1 band with 33 tracking and 99 acquisition channels. The module provides complete signal processing from antenna input to host port in either NMEA messages with the maximum update rate of 10Hz. The module is an ultra-low tracking power consumption device with a high sensitivity of -165dBm while tracking and -147dBm in acquisition mode with fast re-acquisition time. The greater number of visible satellites increases positioning accuracy (<2.5m CEP) and decreases acquisition time (<1.5s TTFF with a warm start). GNSS 3 Click supports anti-jamming, better positioning under weak signal conditions with onboard LNA, and 12 multi-tone active interference cancellers. The SIM33ELA supports EPO (Extended Prediction Orbit) data service that can predict a 7/14/31-day orbit to

customers, with occasional downloads from the EPO server. Information like ephemeris, almanac, rough last position and time, satellite status, and optional time synchronization will reduce TTFF. It can be uploaded to the SIM33ELA module by the host side. EASY (Embedded Assistant System) mode predicts satellite navigation messages from the received ephemeris. The module also supports DGPS SBAS (Satellite Based Augmentation System) and RTCM, where only one mode can be used at a time. The SBAS depends on the user’s continent. The SIM33ELA uses the UART interface with commonly used UART RX and TX pins as its default communication protocol for the host microcontroller. It operates at 115200bps by default configuration to transmit and exchange data. In addition, this Click board™ features other functions accessible through mikroBUS™ signals, such as Reset (RST) for resetting the device and INT pin that could control the module coming

into or waking up from Sleep mode. In addition to the possibility of using the built-in chip antenna, this Click board™ can also use an external active antenna offered by Mikroe, thanks to the onboard n.FL connector and ANT SEL solder jumper set to INT or EXT position. In addition to precise positioning, the GNSS 3 Click also has an accurate timing signal indicated via a red LED indicator marked as PPS, the successful positioning indicated by a yellow LED indicator marked as FIX, and the green PWR LED, which acts as a wake-up indicator. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

GNSS 3 Click hardware overview image

Features overview

Development board

Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an

ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the

first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.

Arduino UNO Rev3 double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

32

RAM (Bytes)

2048

You complete me!

Accessories

Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino UNO board with our Click Shield for Arduino UNO, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Arduino UNO accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
PD2
RST
Wake Up Interrupt
PB2
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
PD0
TX
UART RX
PD1
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

GNSS 3 Click Schematic schematic

Step by step

Project assembly

Click Shield for Arduino UNO front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Arduino UNO Rev3 as your development board.

Click Shield for Arduino UNO front image hardware assembly
Arduino UNO Rev3 front image hardware assembly
Charger 27 Click front image hardware assembly
Prog-cut hardware assembly
Arduino UNO Rev3 Access 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
Arduino UNO 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

This Click board can be interfaced and monitored in two ways:

  • Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.

Software Support

Library Description

This library contains API for GNSS 3 Click driver.

Key functions:

  • gnss3_parse_gngga - GNSS 3 parse GNGGA function

  • gnss3_generic_read - Generic read function

  • gnss3_module_wakeup - Wake-up module.

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * \file 
 * \brief Gnss3 Click example
 * 
 * # Description
 * This example demonstrates the use of GNSS 3 click by reading and displaying
 * the GPS coordinates.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and resets the click board.
 *
 * ## Application Task
 * Reads the received data, parses the GNGGA info from it, and once it receives the position fix
 * it will start displaying the coordinates on the USB UART.
 *
 * ## Additional Function
 * - static void gnss3_clear_app_buf ( void )
 * - static err_t gnss3_process ( gnss3_t *ctx )
 * - static void gnss3_parser_application ( char *rsp )
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "gnss3.h"

#define PROCESS_BUFFER_SIZE 200

static gnss3_t gnss3;
static log_t logger;

static char app_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;
static int32_t app_buf_cnt = 0;

/**
 * @brief GNSS 3 clearing application buffer.
 * @details This function clears memory of application buffer and reset its length and counter.
 * @return None.
 * @note None.
 */
static void gnss3_clear_app_buf ( void );

/**
 * @brief GNSS 3 data reading function.
 * @details This function reads data from device and concatenates data to application buffer.
 * @param[in] ctx : Click context object.
 * See #gnss3_t object definition for detailed explanation.
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read or Application buffer overflow.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t gnss3_process ( gnss3_t *ctx );

/**
 * @brief GNSS 3 parser application.
 * @param[in] rsp Response buffer.
 * @details This function logs GNSS data on the USB UART.
 * @return None.
 * @note None.
 */
static void gnss3_parser_application ( char *rsp );

void application_init ( void )
{
    log_cfg_t log_cfg;
    gnss3_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.

    gnss3_cfg_setup( &cfg );
    GNSS3_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    gnss3_init( &gnss3, &cfg );

    gnss3_module_wakeup( &gnss3 );
    Delay_ms( 1000 );
}

void application_task ( void )
{
    gnss3_process( &gnss3 );
    if ( app_buf_len > ( sizeof ( ( char * ) GNSS3_RSP_GNGGA ) + GNSS3_GNGGA_ELEMENT_SIZE ) ) 
    {
        gnss3_parser_application( app_buf );
    }
}

void main ( void )
{
    application_init( );

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

static void gnss3_clear_app_buf ( void ) 
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
    app_buf_cnt = 0;
}

static err_t gnss3_process ( gnss3_t *ctx ) 
{
    int32_t rx_size = 0;
    char rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    rx_size = gnss3_generic_read( ctx, rx_buf, PROCESS_BUFFER_SIZE );
    if ( rx_size > 0 ) 
    {
        int32_t buf_cnt = 0;
        if ( ( app_buf_len + rx_size ) > PROCESS_BUFFER_SIZE ) 
        {
            gnss3_clear_app_buf(  );
            return GNSS3_ERROR;
        } 
        else 
        {
            buf_cnt = app_buf_len;
            app_buf_len += rx_size;
        }
        for ( int32_t rx_cnt = 0; rx_cnt < rx_size; rx_cnt++ ) 
        {
            if ( rx_buf[ rx_cnt ] ) 
            {
                app_buf[ ( buf_cnt + rx_cnt ) ] = rx_buf[ rx_cnt ];
            }
            else
            {
                app_buf_len--;
                buf_cnt--;
            }
        }
        return GNSS3_OK;
    }
    return GNSS3_ERROR;
}

static void gnss3_parser_application ( char *rsp )
{
    char element_buf[ 100 ] = { 0 };
    if ( GNSS3_OK == gnss3_parse_gngga( rsp, GNSS3_GNGGA_LATITUDE, element_buf ) )
    {
        static uint8_t wait_for_fix_cnt = 0;
        if ( strlen( element_buf ) > 0 )
        {
            log_printf( &logger, "\r\n Latitude: %.2s degrees, %s minutes \r\n", element_buf, &element_buf[ 2 ] );
            gnss3_parse_gngga( rsp, GNSS3_GNGGA_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 ) );
            gnss3_parse_gngga( rsp, GNSS3_GNGGA_ALTITUDE, element_buf );
            log_printf( &logger, " Altitude: %s m \r\n", element_buf );
            wait_for_fix_cnt = 0;
        }
        else
        {
            if ( wait_for_fix_cnt % 5 == 0 )
            {
                log_printf( &logger, " Waiting for the position fix...\r\n\n" );
                wait_for_fix_cnt = 0;
            }
            wait_for_fix_cnt++;
        }
        gnss3_clear_app_buf(  );
    }
}

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

Additional Support

Resources

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