Library Description

Library contains function for getting INT pin state Library contains function for setting CS pin state Library contains function for getting register values Library contains function for setting register values Library contains function for device initialization Library contains function for getting temperature value Library contains function for getting axes values Library contains function for software reset Library contains functions for setting power mode and full scale range

Key functions:

• uint8_t nfctag4_password_present( uint8_t * password_bytes ) - presents password to device in order to open I2C security session.
• uint8_t nfctag4_init( void ) - initializes the device.
• uint8_t nfctag4_enable_mailbox( uint8_t enable_mailbox ) - enables or disables mailbox functionality.

Examples description

The application is composed of three sections :

• System Initialization - Initializes GPIO pins, I2C and LOG modules.
• Application Initialization - Initializes I2C driver, presents password to the device and initializes the device.
• Application Task - Checks if RF placed a message to mailbox and if it did, checks message length and logs message bytes.

void applicationTask( )
{
    nfctag4_wait_for_int( );
    nfctag4_i2c_get( _NFCTAG4_MEMORY_DYNAMIC, _NFCTAG4_DYNAMIC_REG_MB_CTRL, &aux_buffer[0], 1 );

    if (( aux_buffer[0] & 0x04 ) == ( 0x04 ))
    {
        nfctag4_wait_for_int( );
        nfctag4_i2c_get( _NFCTAG4_MEMORY_DYNAMIC, _NFCTAG4_DYNAMIC_REG_MB_LEN, &aux_buffer[0], 1 );
        message_length = aux_buffer[0];
        message_length++;
        nfctag4_wait_for_int( );
        nfctag4_i2c_get( _NFCTAG4_MEMORY_MAILBOX, _NFCTAG4_MAILBOX_REG_BYTE_0, &aux_buffer[0], message_length );

        mikrobus_logWrite( " ", _LOG_LINE );
        mikrobus_logWrite( "> ********* MESSAGE ********* <", _LOG_LINE );

        ByteToStr( message_length, text );
        mikrobus_logWrite( "> Message length : ", _LOG_TEXT );
        mikrobus_logWrite( text, _LOG_TEXT );
        mikrobus_logWrite( " [Bytes]", _LOG_LINE );

        for (i = 0; i < message_length; i ++)
        {
            ByteToStr( i, text );
            mikrobus_logWrite( text, _LOG_TEXT );
            mikrobus_logWrite( " : ", _LOG_TEXT );

            ByteToHex( aux_buffer[ i ], text );
            mikrobus_logWrite( "0x", _LOG_TEXT );
            mikrobus_logWrite( text, _LOG_LINE );
        }

        mikrobus_logWrite( "> *********** END *********** <", _LOG_LINE );
    }
}

Additional Functions :

• nfctag4_wait_for_int( ) - waits for INT pin to go LOW and than HIGH for time period of 300ms.

Other mikroE Libraries used in the example:

• I2C
• UART
• Conversions

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.