Achieve fast data transfer with some Bluetooth magic thanks to the RN4678 and STM32F103RB

/*!
 * \file 
 * \brief RN4678 Click example
 * 
 * # Description
 * This example reads and processes data from RN4678 clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and configures the click board.
 * 
 * ## Application Task  
 * Checks for the received data, reads it and replies with a certain message.
 * 
 * ## Additional Function
 * - rn4678_process ( ) - Logs all the received messages/responses on the USB UART, 
 *                        and if it receives "Hello" string it sends the certain message 
 *                        back to the connected device.
 * 
 * @note
 * We have used the Serial Bluetooth Terminal smartphone application for the test. 
 * A smartphone and the click board must be paired in order to exchange messages with each other.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rn4678.h"
#include "string.h"

#define PROCESS_COUNTER 20
#define PROCESS_RX_BUFFER_SIZE 100
#define PROCESS_PARSER_BUFFER_SIZE 100

#define PROCESS_RSP_ERROR  -1
#define PROCESS_RSP_OK     1
#define PROCESS_NO_RSP     0
#define PROCESS_LOG_RSP    0

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

static rn4678_t rn4678;
static log_t logger;

uint8_t DEVICE_NAME_DATA[ 20 ] = { 'R', 'N', '4', '6', '7', '8', ' ', 'c', 'l', 'i', 'c', 'k' };
uint8_t EXTENDED_STRING_DATA[ 10 ] = { 'S', 'l', 'a', 'v', 'e' };
uint8_t PIN_CODE_DATA[ 10 ] = { '1', '2', '3', '4' };
static char current_parser_buf[ PROCESS_PARSER_BUFFER_SIZE ];

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

static int8_t rn4678_process ( char * response )
{
    int32_t rsp_size;
    uint16_t rsp_cnt = 0;
    
    char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    uint8_t check_buf_cnt;
    uint8_t process_cnt = PROCESS_COUNTER;
    int8_t rsp_flag = 0;
    
    // Clear current buffer
    memset( current_parser_buf, 0, PROCESS_PARSER_BUFFER_SIZE ); 
    
    while( process_cnt != 0 )
    {
        rsp_size = rn4678_generic_read( &rn4678, 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 current 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 );
            
            if ( strstr( current_parser_buf, "ERR" ) ) {
                Delay_100ms( );
                rsp_flag = PROCESS_RSP_ERROR;
                break;
            }
            
            if ( PROCESS_LOG_RSP != response )
            {
                if ( strstr( current_parser_buf, response ) ) {
                    Delay_100ms( );
                    rsp_flag = PROCESS_RSP_OK;
                    break;
                }
            }
            else
            {
                rsp_flag = PROCESS_RSP_OK;
                process_cnt = 1;
            }
            
            if ( strstr( current_parser_buf, "Hello" ) ) {
                rn4678_generic_write( &rn4678, "MikroE\r\n", 8 );
                Delay_100ms( );
                break;
            }
        } 
        else 
        {
            process_cnt--;
            
            // Process delay 
            Delay_ms( 100 );
        }
    }
    
    if ( PROCESS_NO_RSP != rsp_flag )
    {
        log_printf( &logger, "%s", current_parser_buf );
        log_printf( &logger, "\r\n---------------------------\r\n" );
        return rsp_flag;
    }
    
    return PROCESS_NO_RSP;
}

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    rn4678_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.

    rn4678_cfg_setup( &cfg );
    RN4678_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rn4678_init( &rn4678, &cfg );

    rn4678_enable ( &rn4678 );
    Delay_ms( 1000 );
    rn4678_hw_reset ( &rn4678 );
    Delay_ms( 1000 );
    
    log_printf( &logger, "Configuring the module...\n" );
    
    do
    {    
        log_printf( &logger, " --- Command mode --- \r\n" );
        rn4678_enter_command_mode( &rn4678 );
    }
    while( rn4678_process( "CMD" ) != 1 );
    
    do
    {
        log_printf( &logger, " --- Device name --- \r\n" );
        rn4678_set_device_name( &rn4678, &DEVICE_NAME_DATA[ 0 ] );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Status string --- \r\n" );
        rn4678_set_extended_status_string( &rn4678, &EXTENDED_STRING_DATA[ 0 ] );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Operating mode --- \r\n" );
        rn4678_set_operating_mode( &rn4678, 0 );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Authentication --- \r\n" );
        rn4678_set_authentication( &rn4678, 1 );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Pin code --- \r\n" );
        rn4678_set_security_pin_code( &rn4678, &PIN_CODE_DATA[ 0 ] );
    }
    while( rn4678_process( "AOK" ) != 1 );

    do
    {
        log_printf( &logger, " --- Exit command mode --- \r\n" );
        rn4678_exit_command_mode( &rn4678 );
    }
    while( rn4678_process( "END" ) != 1 );
    
    log_printf( &logger, "The module has been configured.\n" );
    
    rn4678_set_cts_pin( &rn4678, 0 );
}

void application_task ( void )
{
    rn4678_process( PROCESS_LOG_RSP );
}

void main ( void )
{
    application_init( );

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


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