Combine WiFi and Bluetooth connectivity for a wide range of applications with NINA-W152 and PIC32MZ2048EFH100

/*!
 * @file main.c
 * @brief NINA-W152 Click Example.
 *
 * # Description
 * Application example shows device capability of connecting to a WiFi network and
 * sending TCP/UDP messages to an echo server, or processing data from a connected BT device.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and logger.
 *
 * ## Application Task
 * Application task is split in few stages:
 *  - NINAW152_POWER_UP:
 * Powers up the device, performs a factory reset and reads system information.
 *
 *  - NINAW152_CONFIGURE_CONNECTION:
 * Configures connection to WiFi or BT depending on the selected example.
 *
 *  - NINAW152_WAIT_FOR_CONNECTION:
 * Checks the connection to WiFi access point.
 *
 *  - NINAW152_EXAMPLE:
 * Depending on the selected demo example, it sends a TCP/UDP message to an echo server over a WiFi network or 
 * processes all data from a connected BT device and sends back an adequate response message.
 *
 * By default, the WiFi TCP/UDP example is selected.
 *
 * ## Additional Function
 * - static void ninaw152_clear_app_buf ( void )
 * - static void ninaw152_log_app_buf ( void )
 * - static err_t ninaw152_process ( ninaw152_t *ctx )
 * - static err_t ninaw152_read_response ( ninaw152_t *ctx, uint8_t *rsp )
 * - static err_t ninaw152_power_up ( ninaw152_t *ctx )
 * - static err_t ninaw152_config_connection ( ninaw152_t *ctx )
 * - static err_t ninaw152_check_connection ( ninaw152_t *ctx )
 * - static err_t ninaw152_example ( ninaw152_t *ctx )
 *
 * @note
 * For the BT example, we have used the Serial Bluetooth Terminal smartphone application for the test. 
 * A smartphone and the click board must be paired to exchange messages.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "ninaw152.h"

// Example selection macros
#define EXAMPLE_WIFI            0               // Example of sending messages to a TCP/UDP echo server over WiFi
#define EXAMPLE_BT              1               // Example of processing data from BT connected device
#define DEMO_EXAMPLE            EXAMPLE_WIFI    // Example selection macro

// WiFi credentials
#define WIFI_SSID               "MikroE Public"
#define WIFI_PASSWORD           "mikroe.guest"

// WiFi 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         "NINA-W152 click board - demo example."

// Application buffer size
#define APP_BUFFER_SIZE         600
#define PROCESS_BUFFER_SIZE     200

/**
 * @brief Example states.
 * @details Predefined enum values for application example state.
 */
typedef enum
{
    NINAW152_POWER_UP = 1,
    NINAW152_CONFIGURE_CONNECTION,
    NINAW152_WAIT_FOR_CONNECTION,
    NINAW152_EXAMPLE

} ninaw152_app_state_t;

static ninaw152_t ninaw152;
static log_t logger;

static uint8_t app_buf[ APP_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;
static ninaw152_app_state_t app_state = NINAW152_POWER_UP;

/**
 * @brief NINA-W152 clearing application buffer.
 * @details This function clears memory of application buffer and reset its length.
 * @note None.
 */
static void ninaw152_clear_app_buf ( void );

/**
 * @brief NINA-W152 log application buffer.
 * @details This function logs data from application buffer to USB UART.
 * @note None.
 */
static void ninaw152_log_app_buf ( void );

/**
 * @brief NINA-W152 data reading function.
 * @details This function reads data from device and concatenates data to application buffer. 
 * @param[in] ctx : Click context object.
 * See #ninaw152_t object definition for detailed explanation.
 * @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 ninaw152_process ( ninaw152_t *ctx );

/**
 * @brief NINA-W152 read response function.
 * @details This function waits for a response message, reads and displays it on the USB UART.
 * @param[in] ctx : Click context object.
 * See #ninaw152_t object definition for detailed explanation.
 * @param[in] rsp  Expected 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.
 * @note None.
 */
static err_t ninaw152_read_response ( ninaw152_t *ctx, uint8_t *rsp );

/**
 * @brief NINA-W152 power up function.
 * @details This function powers up the device, performs a factory reset and reads system information.
 * @param[in] ctx : Click context object.
 * See #ninaw152_t object definition for detailed explanation.
 * @return @li @c    0 - OK.
 *         @li @c != 0 - Read response error.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t ninaw152_power_up ( ninaw152_t *ctx );

/**
 * @brief NINA-W152 config connection function.
 * @details This function configures connection to WiFi or BT depending on the selected example.
 * @param[in] ctx : Click context object.
 * See #ninaw152_t object definition for detailed explanation.
 * @return @li @c    0 - OK.
 *         @li @c != 0 - Read response error.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t ninaw152_config_connection ( ninaw152_t *ctx );

/**
 * @brief NINA-W152 check connection function.
 * @details This function checks the connection to WiFi access point.
 * @param[in] ctx : Click context object.
 * See #ninaw152_t object definition for detailed explanation.
 * @return @li @c    0 - OK.
 *         @li @c != 0 - Read response error.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t ninaw152_check_connection ( ninaw152_t *ctx );

/**
 * @brief NINA-W152 example function.
 * @details This function performs a WiFi TCP/UDP or a BT device terminal example.
 * @param[in] ctx : Click context object.
 * See #ninaw152_t object definition for detailed explanation.
 * @return @li @c    0 - OK.
 *         @li @c != 0 - Read response error.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t ninaw152_example ( ninaw152_t *ctx );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ninaw152_cfg_t ninaw152_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.
    ninaw152_cfg_setup( &ninaw152_cfg );
    NINAW152_MAP_MIKROBUS( ninaw152_cfg, MIKROBUS_1 );
    if ( NINAW152_OK != ninaw152_init( &ninaw152, &ninaw152_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );

    app_state = NINAW152_POWER_UP;
    log_printf( &logger, ">>> APP STATE - POWER UP <<<\r\n\n" );
}

void application_task ( void ) 
{
    switch ( app_state )
    {
        case NINAW152_POWER_UP:
        {
            if ( NINAW152_OK == ninaw152_power_up( &ninaw152 ) )
            {
                app_state = NINAW152_CONFIGURE_CONNECTION;
                log_printf( &logger, ">>> APP STATE - CONFIGURE CONNECTION <<<\r\n\n" );
            }
            break;
        }
        case NINAW152_CONFIGURE_CONNECTION:
        {
            if ( NINAW152_OK == ninaw152_config_connection( &ninaw152 ) )
            {
                app_state = NINAW152_WAIT_FOR_CONNECTION;
                log_printf( &logger, ">>> APP STATE - CHECK CONNECTION <<<\r\n\n" );
            }
            break;
        }
        case NINAW152_WAIT_FOR_CONNECTION:
        {
            if ( NINAW152_OK == ninaw152_check_connection( &ninaw152 ) )
            {
                app_state = NINAW152_EXAMPLE;
                log_printf( &logger, ">>> APP STATE - EXAMPLE <<<\r\n\n" );
            }
            break;
        }
        case NINAW152_EXAMPLE:
        {
            ninaw152_example( &ninaw152 );
            break;
        }
        default:
        {
            log_error( &logger, " APP STATE." );
            break;
        }
    }
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

static void ninaw152_clear_app_buf ( void ) 
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
}

static void ninaw152_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 ninaw152_process ( ninaw152_t *ctx ) 
{
    uint8_t rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    int32_t overflow_bytes = 0;
    int32_t rx_cnt = 0;
    int32_t rx_size = ninaw152_generic_read( ctx, 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 NINAW152_OK;
    }
    return NINAW152_ERROR;
}

static err_t ninaw152_read_response ( ninaw152_t *ctx, uint8_t *rsp ) 
{
    #define READ_RESPONSE_TIMEOUT_MS    60000
    uint32_t timeout_cnt = 0;
    ninaw152_clear_app_buf ( );
    ninaw152_process( ctx );
    while ( ( 0 == strstr( app_buf, rsp ) ) &&
            ( 0 == strstr( app_buf, NINAW152_RSP_ERROR ) ) )
    {
        ninaw152_process( ctx );
        if ( timeout_cnt++ > READ_RESPONSE_TIMEOUT_MS )
        {
            ninaw152_clear_app_buf( );
            log_error( &logger, " Timeout!" );
            return NINAW152_ERROR_TIMEOUT;
        }
        Delay_ms ( 1 );
    }
    Delay_ms ( 200 );
    ninaw152_process( ctx );
    if ( strstr( app_buf, rsp ) )
    {
        ninaw152_log_app_buf( );
        log_printf( &logger, "--------------------------------\r\n" );
        return NINAW152_OK;
    }
    else if ( strstr( app_buf, NINAW152_RSP_ERROR ) )
    {
        log_error( &logger, " CMD!" );
        return NINAW152_ERROR_CMD;
    }
    log_error( &logger, " Unknown!" );
    return NINAW152_ERROR_UNKNOWN;
}

static err_t ninaw152_power_up ( ninaw152_t *ctx )
{
    err_t error_flag = NINAW152_OK;

    log_printf( &logger, ">>> Perform device hardware reset.\r\n" );
    ninaw152_reset_device ( ctx );
    error_flag |= ninaw152_read_response( ctx, NINAW152_URC_GREETING );
    
    log_printf( &logger, ">>> Check communication.\r\n" );
    ninaw152_send_cmd( ctx, NINAW152_CMD_AT );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    log_printf( &logger, ">>> Reset to factory settings.\r\n" );
    ninaw152_send_cmd( ctx, NINAW152_CMD_FACTORY_RESET );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );
    
    log_printf( &logger, ">>> Reboot device.\r\n" );
    ninaw152_send_cmd( ctx, NINAW152_CMD_REBOOT_DEVICE );
    error_flag |= ninaw152_read_response( ctx, NINAW152_URC_GREETING );

    log_printf( &logger, ">>> Get device model ID.\r\n" );
    ninaw152_send_cmd( ctx, NINAW152_CMD_GET_MODEL_ID );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    log_printf( &logger, ">>> Get device software version ID.\r\n" );
    ninaw152_send_cmd( ctx, NINAW152_CMD_GET_SW_VERSION );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    log_printf( &logger, ">>> Get device serial number.\r\n" );
    ninaw152_send_cmd( ctx, NINAW152_CMD_GET_SERIAL_NUM );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    return error_flag;
}

static err_t ninaw152_config_connection ( ninaw152_t *ctx )
{
    err_t error_flag = NINAW152_OK;
#if ( DEMO_EXAMPLE == EXAMPLE_WIFI )
    log_printf( &logger, ">>> Get network host name.\r\n" );
    ninaw152_send_cmd_check( ctx, NINAW152_CMD_NETWORK_HOST_NAME );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    log_printf( &logger, ">>> Set WiFi SSID.\r\n" );
    #define WIFI_CONFIG_ID                  "0"
    #define WIFI_PARAM_TAG_SSID             "2"
    ninaw152_clear_app_buf( );
    strcpy ( app_buf, WIFI_CONFIG_ID );
    strcat ( app_buf, "," );
    strcat ( app_buf, WIFI_PARAM_TAG_SSID );
    strcat ( app_buf, ",\"" );
    strcat ( app_buf, WIFI_SSID );
    strcat ( app_buf, "\"" );
    ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_WIFI_STATION_CONFIG, app_buf );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );
    
    log_printf( &logger, ">>> Set WiFi authentication type to WPA/WPA2/WPA3.\r\n" );
    #define WIFI_PARAM_TAG_AUTH             "5"
    #define WIFI_PARAM_VAL1_WPA_WPA2_WPA3   "2"
    ninaw152_clear_app_buf( );
    strcpy ( app_buf, WIFI_CONFIG_ID );
    strcat ( app_buf, "," );
    strcat ( app_buf, WIFI_PARAM_TAG_AUTH );
    strcat ( app_buf, "," );
    strcat ( app_buf, WIFI_PARAM_VAL1_WPA_WPA2_WPA3 );
    ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_WIFI_STATION_CONFIG, app_buf );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    log_printf( &logger, ">>> Set WiFi Password.\r\n" );
    #define WIFI_PARAM_TAG_PASSWORD         "8"
    ninaw152_clear_app_buf( );
    strcpy ( app_buf, WIFI_CONFIG_ID );
    strcat ( app_buf, "," );
    strcat ( app_buf, WIFI_PARAM_TAG_PASSWORD );
    strcat ( app_buf, ",\"" );
    strcat ( app_buf, WIFI_PASSWORD );
    strcat ( app_buf, "\"" );
    ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_WIFI_STATION_CONFIG, app_buf );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    log_printf( &logger, ">>> Activate WiFi config and try to connect.\r\n" );
    #define WIFI_ACTION_ACTIVATE            "3"
    ninaw152_clear_app_buf( );
    strcpy ( app_buf, WIFI_CONFIG_ID );
    strcat ( app_buf, "," );
    strcat ( app_buf, WIFI_ACTION_ACTIVATE );
    ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_WIFI_STATION_CONFIG_ACTION, app_buf );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );
    ninaw152_clear_app_buf( );
#elif ( DEMO_EXAMPLE == EXAMPLE_BT )
    log_printf( &logger, ">>> Get BT local name.\r\n" );
    ninaw152_send_cmd_check( ctx, NINAW152_CMD_BT_LOCAL_NAME );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );
    ninaw152_clear_app_buf( );
#else
    #error "No demo example selected"
#endif
    return error_flag;
}

static err_t ninaw152_check_connection ( ninaw152_t *ctx )
{
    err_t error_flag = NINAW152_OK;
#if ( DEMO_EXAMPLE == EXAMPLE_WIFI )
    uint8_t * __generic_ptr urc_buf_ptr = 0;
    ninaw152_process( ctx );
    // Wait for WiFi link connected and two network-up URC events
    urc_buf_ptr = strstr( app_buf, NINAW152_URC_WIFI_LINK_CONNECTED );
    if ( urc_buf_ptr )
    {
        urc_buf_ptr = strstr( urc_buf_ptr + 1, NINAW152_URC_NETWORK_UP );
    }
    if ( urc_buf_ptr )
    {
        if ( strstr( urc_buf_ptr + 1, NINAW152_URC_NETWORK_UP ) )
        {
            Delay_ms ( 100 );
            ninaw152_process( ctx );
            ninaw152_log_app_buf( );
            ninaw152_clear_app_buf( );

            // Check WiFi status
            ninaw152_send_cmd( ctx, NINAW152_CMD_WIFI_STATION_STATUS );
            error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );
            Delay_ms ( 1000 );
            Delay_ms ( 1000 );
        }
        else
        {
            error_flag |= NINAW152_ERROR;
        }
    }
    else
    {
        error_flag |= NINAW152_ERROR;
    }
#endif
    return error_flag;
}

static err_t ninaw152_example ( ninaw152_t *ctx )
{
    err_t error_flag = NINAW152_OK;
#if ( DEMO_EXAMPLE == EXAMPLE_WIFI )
    uint8_t * __generic_ptr urc_buf_ptr = 0;
    uint8_t urc_buf[ 30 ] = { 0 };
    uint8_t tcp_peer_handle[ 2 ] = { 0 };
    uint8_t udp_peer_handle[ 2 ] = { 0 };

    log_printf( &logger, ">>> Create and connect TCP socket to remote IP and port.\r\n" );
    #define SCHEME_AT_TCP           "at-tcp"
    ninaw152_clear_app_buf( );
    strcpy ( app_buf, SCHEME_AT_TCP );
    strcat ( app_buf, "://" );
    strcat ( app_buf, REMOTE_IP );
    strcat ( app_buf, ":" );
    strcat ( app_buf, REMOTE_PORT );
    ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_CONNECT_PEER, app_buf );
    error_flag = ninaw152_read_response( ctx, NINAW152_URC_PEER_CONNECTED );
    if ( ( NINAW152_OK == error_flag ) && ( strstr( app_buf, NINAW152_URC_PEER_CONNECTED ) ) )
    {
        urc_buf_ptr = strstr( app_buf, NINAW152_URC_PEER_CONNECTED ) + strlen ( NINAW152_URC_PEER_CONNECTED );
        tcp_peer_handle[ 0 ] = *urc_buf_ptr;
    }

    log_printf( &logger, ">>> Create and connect UDP socket to remote IP and port.\r\n" );
    #define SCHEME_AT_UDP           "at-udp"
    ninaw152_clear_app_buf( );
    strcpy ( app_buf, SCHEME_AT_UDP );
    strcat ( app_buf, "://" );
    strcat ( app_buf, REMOTE_IP );
    strcat ( app_buf, ":" );
    strcat ( app_buf, REMOTE_PORT );
    ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_CONNECT_PEER, app_buf );
    error_flag = ninaw152_read_response( ctx, NINAW152_URC_PEER_CONNECTED );
    if ( ( NINAW152_OK == error_flag ) && ( strstr( app_buf, NINAW152_URC_PEER_CONNECTED ) ) )
    {
        urc_buf_ptr = strstr( app_buf, NINAW152_URC_PEER_CONNECTED ) + strlen ( NINAW152_URC_PEER_CONNECTED );
        udp_peer_handle[ 0 ] = *urc_buf_ptr;
    }
    
    if ( tcp_peer_handle[ 0 ] )
    {
        log_printf( &logger, ">>> Write message to TCP socket and read response.\r\n" );
        #define DATA_FORMAT_STRING      "0"
        #define DATA_FORMAT_BINARY      "2"
        ninaw152_clear_app_buf( );
        strcpy ( app_buf, tcp_peer_handle );
        strcat ( app_buf, "," );
        strcat ( app_buf, DATA_FORMAT_STRING );
        strcat ( app_buf, "," );
        strcat ( app_buf, MESSAGE_CONTENT );
        ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_WRITE_DATA, app_buf );
        if ( NINAW152_OK == ninaw152_read_response( ctx, NINAW152_URC_READ_SOCKET_DATA ) )
        {
            urc_buf_ptr = strstr( app_buf, NINAW152_URC_READ_SOCKET_DATA ) + strlen ( NINAW152_URC_READ_SOCKET_DATA ) + 2;
            memcpy ( urc_buf, urc_buf_ptr, app_buf_len - ( urc_buf_ptr - app_buf ) - 2 );
            strcpy ( app_buf, tcp_peer_handle );
            strcat ( app_buf, "," );
            strcat ( app_buf, DATA_FORMAT_BINARY );
            strcat ( app_buf, "," );
            strcat ( app_buf, urc_buf );
            ninaw152_send_cmd_with_par ( ctx, NINAW152_CMD_READ_DATA, app_buf );
            error_flag |= ninaw152_read_response( ctx, NINAW152_URC_READ_SOCKET_DATA );
        }
    }

    if ( udp_peer_handle[ 0 ] )
    {
        log_printf( &logger, ">>> Write message to UDP socket and read response.\r\n" );
        ninaw152_clear_app_buf( );
        strcpy ( app_buf, udp_peer_handle );
        strcat ( app_buf, "," );
        strcat ( app_buf, DATA_FORMAT_STRING );
        strcat ( app_buf, "," );
        strcat ( app_buf, MESSAGE_CONTENT );
        ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_WRITE_DATA, app_buf );
        if ( NINAW152_OK == ninaw152_read_response( ctx, NINAW152_URC_READ_SOCKET_DATA ) )
        {
            urc_buf_ptr = strstr( app_buf, NINAW152_URC_READ_SOCKET_DATA ) + strlen ( NINAW152_URC_READ_SOCKET_DATA ) + 2;
            memcpy ( urc_buf, urc_buf_ptr, app_buf_len - ( urc_buf_ptr - app_buf ) - 2 );
            strcpy ( app_buf, udp_peer_handle );
            strcat ( app_buf, "," );
            strcat ( app_buf, DATA_FORMAT_BINARY );
            strcat ( app_buf, "," );
            strcat ( app_buf, urc_buf );
            ninaw152_send_cmd_with_par ( ctx, NINAW152_CMD_READ_DATA, app_buf );
            error_flag |= ninaw152_read_response( ctx, NINAW152_URC_READ_SOCKET_DATA );
        }
    }
    
    if ( tcp_peer_handle[ 0 ] )
    {
        log_printf( &logger, ">>> Close TCP socket.\r\n" );
        ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_CLOSE_PEER, tcp_peer_handle );
        error_flag |= ninaw152_read_response( ctx, NINAW152_URC_PEER_DISCONNECTED );
    }

    if ( udp_peer_handle[ 0 ] )
    {
        log_printf( &logger, ">>> Close UDP socket.\r\n" );
        ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_CLOSE_PEER, udp_peer_handle );
        error_flag |= ninaw152_read_response( ctx, NINAW152_URC_PEER_DISCONNECTED );
    }
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
#elif ( DEMO_EXAMPLE == EXAMPLE_BT )
    uint8_t * __generic_ptr urc_buf_ptr = 0;
    uint8_t bt_peer_handle[ 2 ] = { 0 };
    uint32_t timeout_cnt = 0;

    #define BT_TERMINAL_TIMEOUT_MS      60000
    #define BT_TERMINAL_MESSAGE_FREQ_MS 5000
    #define TERMINATION_CMD             "END"
    #define TERMINATION_RESPONSE        "Acknowledged, the connection will be terminated in a few seconds."
    #define TERMINATION_TIMEOUT         "Timeout, closing the connection in a few seconds."
    #define NEW_LINE_STRING             "\r\n"

    log_printf( &logger, ">>> Waiting for a BT peer to establish connection with the click board...\r\n" );
    while ( NINAW152_OK != ninaw152_read_response( ctx, NINAW152_URC_PEER_CONNECTED ) );

    urc_buf_ptr = strstr( app_buf, NINAW152_URC_PEER_CONNECTED ) + strlen ( NINAW152_URC_PEER_CONNECTED );
    bt_peer_handle[ 0 ] = *urc_buf_ptr;

    log_printf( &logger, ">>> Entering data mode. URC and AT commands are not accepted in this mode.\r\n" );
    ninaw152_send_cmd( ctx, NINAW152_CMD_ENTER_DATA_MODE );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );

    log_printf( &logger, ">>> Waiting for data (up to 60 seconds)...\r\n" );
    log_printf( &logger, ">>> Connection will be terminated if the click receives an \"END\" string.\r\n" );
    for ( ; ; )
    {
        ninaw152_clear_app_buf( );
        if ( NINAW152_OK == ninaw152_process( ctx ) )
        {
            Delay_ms ( 100 );
            timeout_cnt = 0;
            ninaw152_process( ctx );
            ninaw152_log_app_buf( );
            if ( strstr( app_buf, TERMINATION_CMD ) )
            {
                log_printf( &logger, ">>> Terminate connection on demand.\r\n" );
                ninaw152_generic_write ( ctx, TERMINATION_RESPONSE, strlen ( TERMINATION_RESPONSE ) );
                ninaw152_generic_write ( ctx, NEW_LINE_STRING, strlen ( NEW_LINE_STRING ) );
                break;
            }
        }
        timeout_cnt++;
        if ( 0 == ( timeout_cnt % BT_TERMINAL_MESSAGE_FREQ_MS ) )
        {
            log_printf( &logger, ">>> Sending \"%s\" message to connected device.\r\n", ( char * ) MESSAGE_CONTENT );
            ninaw152_generic_write ( ctx, MESSAGE_CONTENT, strlen ( MESSAGE_CONTENT ) );
            ninaw152_generic_write ( ctx, NEW_LINE_STRING, strlen ( NEW_LINE_STRING ) );
        }
        if ( BT_TERMINAL_TIMEOUT_MS < timeout_cnt )
        {
            log_printf( &logger, ">>> Terminate connection due to 60s timeout expiration.\r\n" );
            ninaw152_generic_write ( ctx, TERMINATION_TIMEOUT, strlen ( TERMINATION_TIMEOUT ) );
            ninaw152_generic_write ( ctx, NEW_LINE_STRING, strlen ( NEW_LINE_STRING ) );
            break;
        }
        Delay_ms ( 1 );
    }
    Delay_ms ( 1000 );
    log_printf( &logger, ">>> Switching back to command mode.\r\n" );
    ninaw152_set_esc_pin ( ctx, 1 );
    Delay_ms ( 100 );
    ninaw152_set_esc_pin ( ctx, 0 );
    Delay_ms ( 100 );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );
    
    log_printf( &logger, ">>> Closing BT peer connection.\r\n" );
    ninaw152_send_cmd_with_par( ctx, NINAW152_CMD_CLOSE_PEER, bt_peer_handle );
    error_flag |= ninaw152_read_response( ctx, NINAW152_RSP_OK );
#else
    #error "No demo example selected"
#endif
    return error_flag;
}

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