使用LARA-L6004D-01B和STM32F031K6通过先进的LTE（4G）技术确保快速可靠的全球数据传输

创建需要连接并进行远距离通信的设备

LTE Cat.4 3 Click - Data with Nucleo 32 with STM32F031K6 MCU

已发布 10月 01, 2024

点击板

LTE Cat.4 3 Click - Data

开发板

Nucleo 32 with STM32F031K6 MCU

编译器

NECTO Studio

微控制器单元

STM32F031K6

在各种应用中实现可靠的蜂窝连接，特别是在全球或多地区背景下与追踪、监测和通信相关的应用。

硬件概览

它是如何工作的？

LTE Cat.4 3 Click基于u-blox推出的LARA-L6004D-01B，这是LTE Cat 4模块中最小的形态因子。该数据专用模块支持DualStack IPv4/IPv6、FOAT/uFOTA、LwM2M、干扰检测等功能。它在700MHz至2600MHz的频率范围内作为四频设备运行。有两个SMA天线连接器，您应该连接MIKROE提供的适当天线。ANT1天线是主天线，支持TX和RX，而ANT2只支持LTE下行MIMO 2x2和3G RX多样性配置的RX。LTE Cat.4 3 Click具有用于1.8V和3.0V SIM类型的纳米SIM卡插槽。该模块还包括一个USB高速2.0兼容接

口，最小数据速率为480Mbps。该模块本身作为USB设备，并可连接到任何兼容的USB主机。它通过USB提供虚拟串口用于AT命令和通信，以及用于诊断日志的USB虚拟串口等。LTE Cat.4 3 Click使用标准的两线UART接口与主机MCU通信，常用的UART RX和TX支持高达3000000bps（默认为115200）。硬件流控功能也可通过RTS和CTS引脚使用。数据传输也可通过TX LED可视化。除了我们提供的库之外，您还可以使用一组AT命令与模块通信。网络状态可通过STS引脚和STATUS LED获取。该模块可

以通过软件、AT命令或PWR引脚关闭电源。该模块使用来自德州仪器的TXB0106和PCA9306双向转换器进行逻辑电平转换。I2C接口也可用于与主机MCU通信，并带有可选上拉电阻。该Click板™可以使用通过VCC SEL跳线选择的3.3V或5V逻辑电压级别运行。这样，既支持3.3V又支持5V的MCU可以正常使用通信线路。此外，该Click板™配备有包含易于使用的功能和示例代码的库，可用作进一步开发的参考。

LTE Cat.4 3 Click - Data hardware overview image

功能概述

开发板

Nucleo 32开发板搭载STM32F031K6 MCU，提供了一种经济且灵活的平台，适用于使用32引脚封装的STM32微控制器进行实验。该开发板具有Arduino™ Nano连接性，便于通过专用扩展板进行功能扩展，并且支持mbed，使其能够无缝集成在线资源。板载集成

ST-LINK/V2-1调试器/编程器，支持通过USB重新枚举，提供三种接口：虚拟串口（Virtual Com port）、大容量存储和调试端口。该开发板的电源供应灵活，可通过USB VBUS或外部电源供电。此外，还配备了三个LED指示灯（LD1用于USB通信，LD2用于电源

指示，LD3为用户可控LED）和一个复位按钮。STM32 Nucleo-32开发板支持多种集成开发环境（IDEs），如IAR™、Keil®和基于GCC的IDE（如AC6 SW4STM32），使其成为开发人员的多功能工具。

Nucleo 32 with STM32F031K6 MCU double side image

微控制器概述

MCU卡片 / MCU

建筑

ARM Cortex-M0

MCU 内存 (KB)

硅供应商

STMicroelectronics

引脚数

RAM (字节)

4096

你完善了我！

配件

Click Shield for Nucleo-32是扩展您的开发板功能的理想选择，专为STM32 Nucleo-32引脚布局设计。Click Shield for Nucleo-32提供了两个mikroBUS™插座，可以添加来自我们不断增长的Click板™系列中的任何功能。从传感器和WiFi收发器到电机控制和音频放大器，我们应有尽有。Click Shield for Nucleo-32与STM32 Nucleo-32开发板兼容，为用户提供了一种经济且灵活的方式，使用任何STM32微控制器快速创建原型，并尝试各种性能、功耗和功能的组合。STM32 Nucleo-32开发板无需任何独立的探针，因为它集成了ST-LINK/V2-1调试器/编程器，并随附STM32全面的软件HAL库和各种打包的软件示例。这个开发平台为用户提供了一种简便且通用的方式，将STM32 Nucleo-32兼容开发板与他们喜欢的Click板™结合，应用于即将开展的项目中。

Click Shield for Nucleo-32 accessories 1 image

这款多频LTE橡胶天线带可调角度是我们提供的所有3G/4G LTE Click板以及其他需要在全球所有主要蜂窝频段上具有出色吞吐量的设备的绝佳选择。该天线具有SMA公头连接器，可使其直接安装在Click板™或女性SMA模块连接器上。天线位置可以以45度为增量进行调整（0度/45度/90度）。

LTE Cat.4 3 Click - Data accessories 1 image

使用的MCU引脚

mikroBUS™映射器

Network Status

PA0

Module Power-On

PA11

RST

UART RTS

PA4

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

Ring Indicator

PA8

PWM

UART CTS

PA12

INT

UART TX

PA10

UART RX

PA9

I2C Clock

PB6

SCL

I2C Data

PB7

SDA

Power Supply

Ground

GND

“仔细看看！”

Click board™ 原理图

LTE Cat.4 3 Click - Data Schematic schematic

一步一步来

项目组装

Click Shield for Nucleo-144 front image hardware assembly

从选择您的开发板和Click板™开始。以Nucleo 32 with STM32F031K6 MCU作为您的开发板开始。

Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly

Stepper 22 Click front image hardware assembly

Stepper 22 Click complete accessories setup image hardware assembly

Nucleo-32 with STM32 MCU Access MB 1 - upright/background hardware assembly

STM32 M4 Clicker HA MCU/Select Step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

实时跟踪您的结果

应用程序输出

1. 应用程序输出 - 在调试模式下，“应用程序输出”窗口支持实时数据监控，直接提供执行结果的可视化。请按照提供的教程正确配置环境，以确保数据正确显示。

2. UART 终端 - 使用UART Terminal通过USB to UART converter监视数据传输，实现Click board™与开发系统之间的直接通信。请根据项目需求配置波特率和其他串行设置，以确保正常运行。有关分步设置说明，请参考提供的教程。

3. Plot 输出 - Plot功能提供了一种强大的方式来可视化实时传感器数据，使趋势分析、调试和多个数据点的对比变得更加直观。要正确设置，请按照提供的教程，其中包含使用Plot功能显示Click board™读数的分步示例。在代码中使用Plot功能时，请使用以下函数：plot(insert_graph_name, variable_name);。这是一个通用格式，用户需要将“insert_graph_name”替换为实际图表名称，并将“variable_name”替换为要显示的参数。

软件支持

库描述

该库包含 LTE Cat.4 3 Click 驱动程序的 API。

关键功能:

ltecat43_set_power_state - 此函数通过在高电平状态下使用特定时间切换PWR引脚来设置所需的电源状态。
ltecat43_set_sim_apn - 此函数为SIM卡设置APN。
ltecat43_send_sms_text - 此函数将文本消息发送到手机号码。

开源

代码示例

完整的应用程序代码和一个现成的项目可以通过NECTO Studio包管理器直接安装到NECTO Studio。应用程序代码也可以在MIKROE的GitHub账户中找到。

/*!
 * @file main.c
 * @brief LTE Cat.4 3 Click Example.
 *
 * # Description
 * Application example shows device capability of connecting to the network and
 * sending SMS or TCP/UDP messages using standard "AT" commands.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver, restarts the module, and tests the communication.
 *
 * ## Application Task
 * Application task is split in few stages:
 *  - LTECAT43_CONFIGURE_FOR_NETWORK:
 * Sets configuration to device to be able to connect to the network.
 *
 *  - LTECAT43_WAIT_FOR_CONNECTION:
 * Waits for the network registration indicated via CREG URC event and then checks the connection status.
 *
 *  - LTECAT43_CONFIGURE_FOR_EXAMPLE:
 * Sets the device configuration for sending SMS or TCP/UDP messages depending on the selected demo example.
 *
 *  - LTECAT43_EXAMPLE:
 * Depending on the selected demo example, it sends an SMS message (in PDU or TXT mode) or TCP/UDP message.
 *
 * By default, the TCP/UDP example is selected.
 *
 * ## Additional Function
 * - static void ltecat43_clear_app_buf ( void )
 * - static void ltecat43_log_app_buf ( void )
 * - static err_t ltecat43_process ( void )
 * - static void ltecat43_error_check( err_t error_flag )
 * - static err_t ltecat43_rsp_check ( void )
 * - static err_t ltecat43_cfg_for_network( void )
 * - static err_t ltecat43_check_connection( void )
 * - static err_t ltecat43_cfg_for_example( void )
 * - static err_t ltecat43_example( void )
 *
 * @note
 * In order for the examples to work, user needs to set the APN and SMSC (SMS PDU mode only)
 * of entered SIM card as well as the phone number (SMS mode only) to which he wants to send an SMS.
 * Enter valid values for the following macros: SIM_APN, SIM_SMSC and PHONE_NUMBER_TO_MESSAGE.
 * Example:
    SIM_APN "internet"
    SIM_SMSC "+381610401"
    PHONE_NUMBER_TO_MESSAGE "+381659999999"
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "ltecat43.h"
#include "generic_pointer.h"
#include "conversions.h"

// Example selection macros
#define EXAMPLE_TCP_UDP                     0               // Example of sending messages to a TCP/UDP echo server
#define EXAMPLE_SMS                         1               // Example of sending SMS to a phone number
#define DEMO_EXAMPLE                        EXAMPLE_TCP_UDP // Example selection macro

// SIM APN config
#define SIM_APN                             "internet"      // Set valid SIM APN

// SMS example parameters
#define SIM_SMSC                            ""              // Set valid SMS Service Center Address - only in SMS PDU mode
#define PHONE_NUMBER_TO_MESSAGE             ""              // Set Phone number to message
#define SMS_MODE                            "1"             // SMS mode: "0" - PDU, "1" - TXT

// TCP/UDP example parameters
#define REMOTE_IP                           "77.46.162.162" // TCP/UDP echo server IP address
#define REMOTE_PORT                         "51111"         // TCP/UDP echo server port

// Message content
#define MESSAGE_CONTENT                     "LTE Cat.4 3 click board - demo example."

// Application buffer size
#define APP_BUFFER_SIZE                     256
#define PROCESS_BUFFER_SIZE                 256

/**
 * @brief Example states.
 * @details Predefined enum values for application example state.
 */
typedef enum
{
    LTECAT43_CONFIGURE_FOR_NETWORK = 1,
    LTECAT43_WAIT_FOR_CONNECTION,
    LTECAT43_CONFIGURE_FOR_EXAMPLE,
    LTECAT43_EXAMPLE

} ltecat43_example_state_t;

static ltecat43_t ltecat43;
static log_t logger;

/**
 * @brief Application example variables.
 * @details Variables used in application example.
 */
static uint8_t app_buf[ APP_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;
static err_t error_flag = LTECAT43_OK;
static ltecat43_example_state_t example_state;

/**
 * @brief LTE Cat.4 3 clearing application buffer.
 * @details This function clears memory of application buffer and reset its length.
 * @note None.
 */
static void ltecat43_clear_app_buf ( void );

/**
 * @brief LTE Cat.4 3 log application buffer.
 * @details This function logs data from application buffer to USB UART.
 * @note None.
 */
static void ltecat43_log_app_buf ( void );

/**
 * @brief LTE Cat.4 3 data reading function.
 * @details This function reads data from device and concatenates data to application buffer. 
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t ltecat43_process ( void );

/**
 * @brief Check for errors.
 * @details This function checks for different types of
 * errors and logs them on UART or logs the response if no errors occured.
 * @param[in] error_flag  Error flag to check.
 */
static void ltecat43_error_check( err_t error_flag );

/**
 * @brief Response check.
 * @details This function checks for response and
 * returns the status of response.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t ltecat43_rsp_check ( void );

/**
 * @brief Configure device for connection to the network.
 * @details Sends commands to configure and enable
 * connection to the specified network.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t ltecat43_cfg_for_network( void );

/**
 * @brief Wait for connection signal.
 * @details Wait for connection signal from CREG URC.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t ltecat43_check_connection( void );

/**
 * @brief Configure device for example.
 * @details Configure device for the specified example.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t ltecat43_cfg_for_example( void );

/**
 * @brief Execute example.
 * @details This function executes SMS or TCP/UDP example depending on the DEMO_EXAMPLE macro.
 * @return @li @c  0 - OK response.
 *         @li @c -2 - Timeout error.
 *         @li @c -3 - Command error.
 *         @li @c -4 - Unknown error.
 * See #err_t definition for detailed explanation.
 */
static err_t ltecat43_example( void );

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ltecat43_cfg_t ltecat43_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.
    ltecat43_cfg_setup( &ltecat43_cfg );
    LTECAT43_MAP_MIKROBUS( ltecat43_cfg, MIKROBUS_1 );
    if ( UART_ERROR == ltecat43_init( &ltecat43, &ltecat43_cfg ) )
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );
        for ( ; ; );
    }

    ltecat43_set_power_state ( &ltecat43, LTECAT43_POWER_STATE_ON );

    ltecat43_process( );
    ltecat43_clear_app_buf( );

    // Check communication
    ltecat43_send_cmd( &ltecat43, LTECAT43_CMD_AT );
    error_flag = ltecat43_rsp_check( );
    ltecat43_error_check( error_flag );

    // Restart device
    #define RESTART_DEVICE "1,1"
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_CFUN, RESTART_DEVICE );
    error_flag = ltecat43_rsp_check( );
    ltecat43_error_check( error_flag );

    log_info( &logger, " Application Task " );
    example_state = LTECAT43_CONFIGURE_FOR_NETWORK;
}

void application_task ( void )
{
    switch ( example_state )
    {
        case LTECAT43_CONFIGURE_FOR_NETWORK:
        {
            if ( LTECAT43_OK == ltecat43_cfg_for_network( ) )
            {
                example_state = LTECAT43_WAIT_FOR_CONNECTION;
            }
            break;
        }
        case LTECAT43_WAIT_FOR_CONNECTION:
        {
            if ( LTECAT43_OK == ltecat43_check_connection( ) )
            {
                example_state = LTECAT43_CONFIGURE_FOR_EXAMPLE;
            }
            break;
        }
        case LTECAT43_CONFIGURE_FOR_EXAMPLE:
        {
            if ( LTECAT43_OK == ltecat43_cfg_for_example( ) )
            {
                example_state = LTECAT43_EXAMPLE;
            }
            break;
        }
        case LTECAT43_EXAMPLE:
        {
            ltecat43_example( );
            break;
        }
        default:
        {
            log_error( &logger, " Example state." );
            break;
        }
    }
}

void main ( void )
{
    application_init( );

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

static void ltecat43_clear_app_buf ( void )
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
}

static void ltecat43_log_app_buf ( void )
{
    for ( int32_t buf_cnt = 0; buf_cnt < app_buf_len; buf_cnt++ )
    {
        log_printf( &logger, "%c", app_buf[ buf_cnt ] );
    }
}

static err_t ltecat43_process ( void )
{
    uint8_t rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    int32_t overflow_bytes = 0;
    int32_t rx_cnt = 0;
    int32_t rx_size = ltecat43_generic_read( &ltecat43, rx_buf, PROCESS_BUFFER_SIZE );
    if ( ( rx_size > 0 ) && ( rx_size <= APP_BUFFER_SIZE ) ) 
    {
        if ( ( app_buf_len + rx_size ) > APP_BUFFER_SIZE ) 
        {
            overflow_bytes = ( app_buf_len + rx_size ) - APP_BUFFER_SIZE;
            app_buf_len = APP_BUFFER_SIZE - rx_size;
            memmove ( app_buf, &app_buf[ overflow_bytes ], app_buf_len );
            memset ( &app_buf[ app_buf_len ], 0, overflow_bytes );
        }
        for ( rx_cnt = 0; rx_cnt < rx_size; rx_cnt++ ) 
        {
            if ( rx_buf[ rx_cnt ] ) 
            {
                app_buf[ app_buf_len++ ] = rx_buf[ rx_cnt ];
            }
        }
        return LTECAT43_OK;
    }
    return LTECAT43_ERROR;
}

static err_t ltecat43_rsp_check ( void )
{
    uint32_t timeout_cnt = 0;
    uint32_t timeout = 120000;
    ltecat43_clear_app_buf( );
    ltecat43_process( );
    while ( ( 0 == strstr( app_buf, LTECAT43_RSP_OK ) ) &&
            ( 0 == strstr( app_buf, LTECAT43_RSP_ERROR ) ) )
    {
        ltecat43_process( );
        if ( timeout_cnt++ > timeout )
        {
            ltecat43_clear_app_buf( );
            return LTECAT43_ERROR_TIMEOUT;
        }
        Delay_ms( 1 );
    }
    Delay_ms( 100 );
    ltecat43_process( );
    if ( strstr( app_buf, LTECAT43_RSP_OK ) )
    {
        return LTECAT43_OK;
    }
    else if ( strstr( app_buf, LTECAT43_RSP_ERROR ) )
    {
        return LTECAT43_ERROR_CMD;
    }
    else
    {
        return LTECAT43_ERROR_UNKNOWN;
    }
}

static void ltecat43_error_check( err_t error_flag )
{
    switch ( error_flag )
    {
        case LTECAT43_OK:
        {
            ltecat43_log_app_buf( );
            break;
        }
        case LTECAT43_ERROR:
        {
            log_error( &logger, " Overflow!" );
            break;
        }
        case LTECAT43_ERROR_TIMEOUT:
        {
            log_error( &logger, " Timeout!" );
            break;
        }
        case LTECAT43_ERROR_CMD:
        {
            log_error( &logger, " CMD!" );
            break;
        }
        case LTECAT43_ERROR_UNKNOWN:
        default:
        {
            log_error( &logger, " Unknown!" );
            break;
        }
    }
    Delay_ms( 500 );
}

static err_t ltecat43_cfg_for_network( void )
{
    err_t func_error = LTECAT43_OK;
    // Deregister from network
    Delay_ms ( 10000 );
    #define DEREGISTER_FROM_NETWORK "2"
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_COPS, DEREGISTER_FROM_NETWORK );
    error_flag = ltecat43_rsp_check();
    func_error |= error_flag;
    ltecat43_error_check( error_flag );
    
    // Set SIM APN
    ltecat43_set_sim_apn( &ltecat43, SIM_APN );
    error_flag = ltecat43_rsp_check();
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    // Enable full functionality
    #define FULL_FUNCTIONALITY "1"
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_CFUN, FULL_FUNCTIONALITY );
    error_flag = ltecat43_rsp_check();
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    // Enable network registartion
    #define ENABLE_REG "2"
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_CREG, ENABLE_REG );
    error_flag = ltecat43_rsp_check();
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    // Automatic registration
    #define AUTOMATIC_REGISTRATION "0"
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_COPS, AUTOMATIC_REGISTRATION );
    error_flag = ltecat43_rsp_check();
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    return func_error;
}

static err_t ltecat43_check_connection( void )
{
    #define CONNECTED "+CREG: 2,1"
    ltecat43_send_cmd_check ( &ltecat43, LTECAT43_CMD_CREG );
    error_flag = ltecat43_rsp_check( );
    ltecat43_error_check( error_flag );
    if ( strstr( app_buf, CONNECTED ) )
    {
        Delay_ms( 100 );
        ltecat43_process( );
        ltecat43_log_app_buf( );
        log_printf( &logger, "\r\n" );
        ltecat43_clear_app_buf( );
        // Check signal quality
        ltecat43_send_cmd( &ltecat43, LTECAT43_CMD_CSQ );
        error_flag = ltecat43_rsp_check( );
        ltecat43_error_check( error_flag );
        return error_flag;
    }
    Delay_ms ( 1000 );
    return LTECAT43_ERROR;
}

static err_t ltecat43_cfg_for_example( void )
{
    err_t func_error = LTECAT43_OK;
#if ( DEMO_EXAMPLE == EXAMPLE_TCP_UDP )
    #define ACTIVATE_PDP_CONTEXT "1,1"
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_CGACT, ACTIVATE_PDP_CONTEXT );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );
#elif ( DEMO_EXAMPLE == EXAMPLE_SMS )
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_CMGF, SMS_MODE );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );
#else
    #error "No demo example selected"
#endif
    return func_error;
}

static err_t ltecat43_example( void )
{
    err_t func_error = LTECAT43_OK;
#if ( DEMO_EXAMPLE == EXAMPLE_TCP_UDP )
    uint8_t cmd_buf[ 100 ] = { 0 };
    uint8_t urc_buf[ 20 ] = { 0 };
    uint16_t timeout_cnt = 0;
    uint16_t timeout = 30000;
    uint8_t * __generic_ptr socket_num_buf = 0;
    uint8_t tcp_socket_num[ 2 ] = { 0 };
    uint8_t udp_socket_num[ 2 ] = { 0 };

    // Create TCP socket
    #define RSP_USOCR "+USOCR: "
    #define TCP_PROTOCOL "6"
    ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USOCR, TCP_PROTOCOL );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    socket_num_buf = strstr( app_buf, RSP_USOCR ) + strlen ( RSP_USOCR );
    tcp_socket_num[ 0 ] = *socket_num_buf;
    ltecat43_error_check( error_flag );

    // Create UDP socket
    #define UDP_PROTOCOL "17"
    ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USOCR, UDP_PROTOCOL );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    socket_num_buf = strstr( app_buf, RSP_USOCR ) + strlen ( RSP_USOCR );
    udp_socket_num[ 0 ] = *socket_num_buf;
    ltecat43_error_check( error_flag );

    // Connect TCP socket to remote IP and port
    strcpy( cmd_buf, tcp_socket_num );
    strcat( cmd_buf, ",\"" );
    strcat( cmd_buf, REMOTE_IP );
    strcat( cmd_buf, "\"," );
    strcat( cmd_buf, REMOTE_PORT );
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_USOCO, cmd_buf );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    // Connect UDP socket to remote IP and port
    strcpy( cmd_buf, udp_socket_num );
    strcat( cmd_buf, ",\"" );
    strcat( cmd_buf, REMOTE_IP );
    strcat( cmd_buf, "\"," );
    strcat( cmd_buf, REMOTE_PORT );
    ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USOCO, cmd_buf );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    // Get message length
    uint8_t message_len_buf[ 5 ] = { 0 };
    uint16_t message_len = strlen( MESSAGE_CONTENT );
    uint16_to_str( message_len, message_len_buf );
    l_trim( message_len_buf );
    r_trim( message_len_buf );

    // Write message to TCP socket
    strcpy( cmd_buf, tcp_socket_num );
    strcat( cmd_buf, "," );
    strcat( cmd_buf, message_len_buf );
    strcat( cmd_buf, ",\"" );
    strcat( cmd_buf, MESSAGE_CONTENT );
    strcat( cmd_buf, "\"" );
    ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USOWR, cmd_buf );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    // Read response message from TCP socket
    #define URC_READ_SOCKET_DATA_TCP "+UUSORD: "
    strcpy( urc_buf, URC_READ_SOCKET_DATA_TCP );
    strcat( urc_buf, tcp_socket_num );
    for ( ; ; )
    {
        ltecat43_process( );
        uint8_t * __generic_ptr start_response_buf = strstr( app_buf, urc_buf );
        if ( start_response_buf )
        {
            Delay_ms( 100 );
            ltecat43_process( );
            uint8_t response_len_buf[ 5 ] = { 0 };
            uint8_t * __generic_ptr start_response_len = strstr( start_response_buf, "," ) + 1;
            memcpy ( response_len_buf, start_response_len, app_buf_len - ( start_response_len - app_buf ) );
            strcpy( cmd_buf, tcp_socket_num );
            strcat( cmd_buf, "," );
            strcat( cmd_buf, response_len_buf );
            ltecat43_log_app_buf( );
            ltecat43_clear_app_buf( );
            ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USORD, cmd_buf );
            error_flag = ltecat43_rsp_check( );
            func_error |= error_flag;
            ltecat43_error_check( error_flag );
            break;
        }
        if ( timeout_cnt++ > timeout )
        {
            break;
        }
        Delay_ms( 1 );
    }
    timeout_cnt = 0;

    // Write message to UDP socket
    strcpy( cmd_buf, udp_socket_num );
    strcat( cmd_buf, "," );
    strcat( cmd_buf, message_len_buf );
    strcat( cmd_buf, ",\"" );
    strcat( cmd_buf, MESSAGE_CONTENT );
    strcat( cmd_buf, "\"" );
    ltecat43_send_cmd_par( &ltecat43, LTECAT43_CMD_USOWR, cmd_buf );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );

    // Read response message from UDP socket
    #define URC_READ_SOCKET_DATA_UDP "+UUSORD: "
    strcpy( urc_buf, URC_READ_SOCKET_DATA_UDP );
    strcat( urc_buf, udp_socket_num );
    for ( ; ; )
    {
        ltecat43_process( );
        uint8_t * __generic_ptr start_response_buf = strstr( app_buf, urc_buf );
        if ( start_response_buf )
        {
            Delay_ms( 100 );
            ltecat43_process( );
            uint8_t response_len_buf[ 5 ] = { 0 };
            uint8_t * __generic_ptr start_response_len = strstr( start_response_buf, "," ) + 1;
            memcpy ( response_len_buf, start_response_len, app_buf_len - ( start_response_len - app_buf ) );
            strcpy( cmd_buf, udp_socket_num );
            strcat( cmd_buf, "," );
            strcat( cmd_buf, response_len_buf );
            ltecat43_log_app_buf( );
            ltecat43_clear_app_buf( );
            ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USORF, cmd_buf );
            error_flag = ltecat43_rsp_check( );
            func_error |= error_flag;
            ltecat43_error_check( error_flag );
            break;
        }
        if ( timeout_cnt++ > timeout )
        {
            break;
        }
        Delay_ms( 1 );
    }
    
    // Close TCP socket
    ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USOCL, tcp_socket_num );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );
    
    // Close UDP socket
    ltecat43_send_cmd_par ( &ltecat43, LTECAT43_CMD_USOCL, udp_socket_num );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );
    Delay_ms( 5000 );
#elif ( DEMO_EXAMPLE == EXAMPLE_SMS )
    // Check SMS mode
    #define CMGF_PDU "+CMGF: 0"
    #define CMGF_TXT "+CMGF: 1"
    ltecat43_send_cmd_check( &ltecat43, LTECAT43_CMD_CMGF );
    error_flag = ltecat43_rsp_check( );
    func_error |= error_flag;
    ltecat43_error_check( error_flag );
    if ( strstr( app_buf, CMGF_PDU ) )
    {
        // Send SMS in PDU mode
        ltecat43_send_sms_pdu( &ltecat43, SIM_SMSC, PHONE_NUMBER_TO_MESSAGE, MESSAGE_CONTENT );
        error_flag = ltecat43_rsp_check( );
        func_error |= error_flag;
        ltecat43_error_check( error_flag );
    }
    else if ( strstr( app_buf, CMGF_TXT ) )
    {
        // Send SMS in TXT mode
        ltecat43_send_sms_text ( &ltecat43, PHONE_NUMBER_TO_MESSAGE, MESSAGE_CONTENT );
        error_flag = ltecat43_rsp_check( );
        func_error |= error_flag;
        ltecat43_error_check( error_flag );
    }
    Delay_ms( 10000 );
    Delay_ms( 10000 );
    Delay_ms( 10000 );
#else
    #error "No demo example selected"
#endif
    return func_error;
}

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