NFC Tag 4 click

NFC Tag 4 Click is NFC tag device, offering 16 Kbit of electrically erasable programmable memory (EEPROM).

click Product page

Click library

• Author : MikroE Team
• Date : Jan 2020.
• Type : I2C type

Software Support

We provide a library for the NfcTag4 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for NfcTag4 Click driver.

Standard key functions :

• Config Object Initialization function.

  void nfctag4_cfg_setup ( nfctag4_cfg_t *cfg );

• Initialization function.

  NFCTAG4_RETVAL nfctag4_init ( nfctag4_t ctx, nfctag4_cfg_t cfg );

• Click Default Configuration function.

  void nfctag4_default_cfg ( nfctag4_t *ctx );

Example key functions :

• This function presents password to device in order to open I2C security session

  uint8_t nfctag4_password_present ( nfctag4_t ctx, uint8_t password_bytes );

• This function enables or disables mailbox functionality

  uint8_t nfctag4_enable_mailbox ( nfctag4_t* ctx, uint8_t enable_mailbox );

• This function enables or disables RF functionality

  uint8_t nfctag4_enable_rf ( nfctag4_t* ctx, uint8_t enable_rf );

Examples Description

This example showcases how to configure and use the NFC Tag 4 click. The click is an NFC tag interface which uses the I2C serial interface and an RF link interface in order to communicate. The example requires the ST25 NFC Tap application which can be downloaded to your phone.

The demo application is composed of two sections :

Application Init

This function initializes and configures the logger and click modules.

void application_init ( void )
{
    log_cfg_t log_cfg;
    nfctag4_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 ----" );

    nfctag4_cfg_setup( &cfg );
    NFCTAG4_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    nfctag4_init( &nfctag4, &cfg );

    nfctag4_default_cfg( &nfctag4 );
}

Application Task

This function waits for the interrupt signal, after which it expects data transfers. Once some data has been detected it will open a communication channel with the device transmitting it and show the received data in the UART console.

void application_task ( void )
{
    nfctag4_wait_for_int( );

    info.memory_area = NFCTAG4_MEMORY_DYNAMIC;
    info.register_address = NFCTAG4_DYNAMIC_REG_MB_CTRL;
    info.n_registers = 1;
    nfctag4_i2c_get( &nfctag4, &info, aux_buffer );

    if ( ( aux_buffer[ 0 ] & 0x04 ) == ( 0x04 ) )
    {
        nfctag4_wait_for_int( );
        info.memory_area = NFCTAG4_MEMORY_DYNAMIC;
        info.register_address = NFCTAG4_DYNAMIC_REG_MB_LEN;
        info.n_registers = 1;
        nfctag4_i2c_get( &nfctag4, &info, aux_buffer );
        message_length = aux_buffer[ 0 ];
        message_length++;
        nfctag4_wait_for_int( );
        info.memory_area = NFCTAG4_MEMORY_MAILBOX;
        info.register_address = NFCTAG4_MAILBOX_REG_BYTE_0;
        info.n_registers = message_length;
        nfctag4_i2c_get( &nfctag4, &info, aux_buffer );

        log_printf( &logger, "************* MESSAGE ***************\r\n" );
        log_printf( &logger, " ** Message length:  %u Bytes**\r\n", message_length );

        for ( i = 0; i < message_length; i++ )
        {
            log_printf( &logger, " %u : 0x%x\r\n", i, ( uint16_t ) aux_buffer[ i ] );
        }

        log_printf( &logger, "************** END ****************\r\n" );
    }
}  

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.NfcTag4

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.