Provide CAN FD communication with advanced fail-safe mechanisms using ATA6501 and ATmega328

/*!
 * @file main.c
 * @brief ATA6501 Click Example.
 *
 * # Description
 * This example demonstrates the use of an ATA6501 Click board by showing
 * the communication between the two Click boards.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and logger.
 *
 * ## Application Task
 * Depending on the selected application mode, it reads all the received data or 
 * sends the desired message every 3 seconds.
 *
 * ## Additional Function
 * - static void ata6501_clear_app_buf ( void )
 * - static void ata6501_log_app_buf ( void )
 * - static err_t ata6501_process ( ata6501_t *ctx )
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "ata6501.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

// Text message to send in the transmitter application mode
#define DEMO_TEXT_MESSAGE           "MIKROE - ATA6501 Click board\r\n"

// Application buffer size
#define APP_BUFFER_SIZE             500
#define PROCESS_BUFFER_SIZE         200

static ata6501_t ata6501;
static log_t logger;

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

/**
 * @brief ATA6501 clearing application buffer.
 * @details This function clears memory of application buffer and reset its length.
 * @note None.
 */
static void ata6501_clear_app_buf ( void );

/**
 * @brief ATA6501 log application buffer.
 * @details This function logs data from application buffer to USB UART.
 * @note None.
 */
static void ata6501_log_app_buf ( void );

/**
 * @brief ATA6501 data reading function.
 * @details This function reads data from device and concatenates data to application buffer. 
 * @param[in] ctx : Click context object.
 * See #ata6501_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 ata6501_process ( ata6501_t *ctx );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ata6501_cfg_t ata6501_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.
    ata6501_cfg_setup( &ata6501_cfg );
    ATA6501_MAP_MIKROBUS( ata6501_cfg, MIKROBUS_1 );
    if ( UART_ERROR == ata6501_init( &ata6501, &ata6501_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
#ifdef DEMO_APP_TRANSMITTER
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    ata6501_generic_write( &ata6501, DEMO_TEXT_MESSAGE, strlen( DEMO_TEXT_MESSAGE ) );
    log_printf( &logger, "%s", ( char * ) DEMO_TEXT_MESSAGE );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 ); 
#else
    if ( ATA6501_OK == ata6501_process( &ata6501 ) ) 
    {
        ata6501_log_app_buf ( );
        ata6501_clear_app_buf ( );
    }
#endif
}

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 ata6501_clear_app_buf ( void ) 
{
    memset( app_buf, 0, app_buf_len );
    app_buf_len = 0;
}

static void ata6501_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 ata6501_process ( ata6501_t *ctx ) 
{
    uint8_t rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    int32_t overflow_bytes = 0;
    int32_t rx_cnt = 0;
    int32_t rx_size = ata6501_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 ATA6501_OK;
    }
    return ATA6501_ERROR;
}

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