Join the NFC revolution and see how it's making your digital world accessible with a touch, enabling a new era of convenience and connectivity
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Hardware Overview
How does it work?
NFC 4 Click is based on the ST25R3916, a high-performance multi-purpose NFC transceiver supporting NFC initiator, NFC target, reader, and card emulation modes from STMicroelectronics. It features high RF output power to directly drive an antenna etched on the PCB, alongside its tuning circuit, at high efficiency. Besides being fully compliant with EMVCo 3.0, it also includes an advanced analog front end and a highly integrated data framing system for ISO 18092 passive and active initiator and target, NFC-A/B (ISO 14443A/B) reader including higher bit rates, NFC-F (FeliCa™) reader, NFC-V (ISO 15693) reader up to 53 kbps, and NFC-A / NFC-F card emulation. Due to this combination of high RF output power and low power modes, this Click board™ is ideally suited for infrastructure NFC applications. The ST25R3916 features a built-in A/D converter,
which input can be multiplexed from different sources for diagnostic functions and low-power card detection. The result of the A/D conversion is stored in a register that can be read through the selectable host interface. It also contains a low-power capacitive sensor to detect the presence of a card without switching on the reader field by measuring the amplitude or phase of the antenna signal. Also, an integrated low-power RC oscillator and a wake-up timer automatically wake up the ST25R3916 and check for the presence of a tag using one or more techniques of low-power detection of card presence (capacitive, phase, or amplitude). NFC 4 Click communicates with a microcontroller via an SPI interface or an I2C interface. The ST25R3916 acts as a peripheral device on both interfaces, relying on the microcontroller to initiate all communication. The
communication selection can be made by positioning SMD jumpers labeled COMM SEL to an appropriate position. Note that all the jumpers' positions must be on the same side, or the Click board™ may become unresponsive. This Click board™ also features an additional interrupt signal routed on the INT pin of the mikroBUS™ socket to notify the microcontroller of completed commands or external events (e.g., peer device field on). This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.
Features overview
Development board
Nucleo-64 with STM32F103RB MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU

Architecture
ARM Cortex-M3
MCU Memory (KB)
128
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
20480
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic

Step by step
Project assembly
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support
Library Description
This library contains API for NFC 4 Click driver.
Key functions:
nfc4_get_mifare_tag_uid
- This function reads the UID of a mifare tag.nfc4_write_register
- This function writes a desired data to the selected register.nfc4_read_register
- This function reads a desired data from the selected register.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief NFC4 Click example
*
* # Description
* This example demonstrates the use of NFC 4 Click board
* by reading MIFARE ISO/IEC 14443 type A tag UID.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration.
*
* ## Application Task
* If there's a tag detected, it reads its UID and displays it on the USB UART every 500ms.
*
* @note
* For testing purposes we used MIKROE-1475 - an RFiD tag 13.56MHz compliant with ISO14443-A standard.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "nfc4.h"
static nfc4_t nfc4;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
nfc4_cfg_t nfc4_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.
nfc4_cfg_setup( &nfc4_cfg );
NFC4_MAP_MIKROBUS( nfc4_cfg, MIKROBUS_1 );
err_t init_flag = nfc4_init( &nfc4, &nfc4_cfg );
if ( ( I2C_MASTER_ERROR == init_flag ) || ( SPI_MASTER_ERROR == init_flag ) )
{
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
NFC4_SET_DATA_SAMPLE_EDGE;
if ( NFC4_ERROR == nfc4_default_cfg ( &nfc4 ) )
{
log_error( &logger, " Default Config Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
uint8_t tag_uid[ 10 ] = { 0 };
uint8_t uid_len = 0;
if( NFC4_OK == nfc4_get_mifare_tag_uid( &nfc4, tag_uid, &uid_len ) )
{
log_printf( &logger, " Tag UID: " );
for ( uint8_t cnt = 0; cnt < uid_len; cnt++ )
{
log_printf( &logger, "%.2X", ( uint16_t ) tag_uid[ cnt ] );
}
log_printf( &logger, "\r\n" );
Delay_ms( 500 );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END