Read data from NFC tags or write data to them with ST25R95 and PIC32MZ2048EFH100

NFC transceiver for contactless communication

Published Feb 08, 2024

Click board™

NFC 6 Click

Dev. board

Flip&Click PIC32MZ

Compiler

NECTO Studio

MCU

PIC32MZ2048EFH100

Achieve convenient and secure communication between devices using Near Field Communication (NFC) technology

Hardware Overview

How does it work?

NFC 6 Click is based on the ST25R95, a near-field communication transceiver from STMicroelectronics. It manages frame coding and decoding in Reader and card emulation modes for standard applications such as near-field communication (NFC), proximity, and vicinity standards. The NFC transceiver supports ISO/IEC 14443 Type A communication in reader and card emulation modes and ISO/IEC 14443 Type B, ISO/IEC15693, and FeliCa in reader mode. The ST25R95 embeds an analog front end to provide the 13.56 MHz air interface and supports the detection, reading, and writing of NFC Forum Type

1, 2, 3, 4, and 5 tags. There are two operating modes that ST25R95 supports: wait for event (WFE) and active mode. In active mode, the transceiver communicates actively with a tag or an external host, while the WFE mode includes four low-consumption states: power-up, hibernate, sleep/field detector, and tag detector. NFC 6 Click uses a standard 4-wire SPI serial interface to communicate with the host MCU, supporting clock frequencies of up to 2MHz. There are two interrupt pins: interrupt input (II) and interrupt output (IO). The interrupt input allows you to control WFE events. When it is ready, the NFC transceiver

returns a replay over the interrupt output by setting it to a Low logic level. It will remain Low until the host MCU reads the data. The application can use the Interrupt mode to skip the polling stage. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the V SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

Features overview

Development board

Flip&Click PIC32MZ is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller, the PIC32MZ2048EFH100 from Microchip, four mikroBUS™ sockets for Click board™ connectivity, two USB connectors, LED indicators, buttons, debugger/programmer connectors, and two headers compatible with Arduino-UNO pinout. Thanks to innovative manufacturing technology,

it allows you to build gadgets with unique functionalities and features quickly. Each part of the Flip&Click PIC32MZ development kit contains the components necessary for the most efficient operation of the same board. In addition, there is the possibility of choosing the Flip&Click PIC32MZ programming method, using the chipKIT bootloader (Arduino-style development environment) or our USB HID bootloader using mikroC, mikroBasic, and mikroPascal for PIC32. This kit includes a clean and regulated power supply block through the USB Type-C (USB-C) connector. All communication

methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, user-configurable buttons, and LED indicators. Flip&Click PIC32MZ development kit allows you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

Microcontroller Overview

MCU Card / MCU

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

You complete me!

Accessories

RFID tag operating at 13.56MHz adheres to the ISO14443-A standard, ensuring high-frequency communication. This proximity card technology, often exemplified by MIFARE cards, facilitates secure and contactless interactions in applications like access control, public transport, and payment systems. The ISO14443-A standard defines the communication protocol, incorporating anti-collision mechanisms for simultaneous card handling. These RFID tags possess variable memory capacities, ranging from a few bytes to kilobytes, catering to diverse application needs. Ensuring data security, the standard integrates features such as encryption and authentication. These tags, exemplified by MIFARE technology, are widely used for their efficiency and are vital in enhancing convenience and security in diverse identification and access scenarios.

Used MCU Pins

mikroBUS™ mapper

ID SEL

RE2

RST

SPI Select / ID COMM

RA0

SPI Clock

RG6

SCK

SPI Data OUT

RC4

MISO

SPI Data IN

RB5

MOSI

Power Supply

3.3V

Ground

GND

Interrupt Input

RC14

PWM

Interrupt Output

RD9

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Flip&Click PIC32MZ front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Flip&Click PIC32MZ as your development board.

GNSS2 Click front image hardware assembly

GNSS2 Click complete accessories setup image hardware assembly

Board mapper by product7 hardware assembly

Flip&Click PIC32MZ MCU step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

Software Support

Library Description

This library contains API for NFC 6 Click driver.

Key functions:

nfc6_send_command - This function sends a desired command by using SPI serial interface
nfc6_read_data - This function reads a response data bytes by using SPI serial interface
nfc6_read_mifare_tag_uid - This function reads the UID of a MIFARE ISO14443-A type tags with 4-byte or 7-byte UIDs

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 NFC 6 Click example
 *
 * # Description
 * This example demonstrates the use of NFC 6 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 logger, performs the Click default configuration and
 * reads the device ID.
 *
 * ## Application Task
 * If there's a tag detected, it reads its UID and displays it on the USB UART every 500ms.
 *
 * @note
 * Only ISO14443-A type tags with 4-byte or 7-byte UIDs are compatible with this example.
 * We recommend MIKROE-1475 - an RFiD tag 13.56MHz compliant with ISO14443-A standard.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "nfc6.h"

static nfc6_t nfc6;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    nfc6_cfg_t nfc6_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.
    nfc6_cfg_setup( &nfc6_cfg );
    NFC6_MAP_MIKROBUS( nfc6_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == nfc6_init( &nfc6, &nfc6_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( NFC6_ERROR == nfc6_default_cfg ( &nfc6 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    uint8_t device_id[ 13 ] = { 0 };
    nfc6_send_command ( &nfc6, NFC6_CMD_IDN, NULL, NULL );
    if ( NFC6_OK == nfc6_read_data ( &nfc6, device_id, sizeof ( device_id ), NULL ) )
    {
        log_printf ( &logger, " Device ID: %s\r\n", device_id );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    uint8_t tag_uid[ NFC6_TAG_UID_MAX_LEN ] = { 0 };
    uint8_t tag_uid_len = 0;
    if ( NFC6_OK == nfc6_read_mifare_tag_uid ( &nfc6, tag_uid, &tag_uid_len ) )
    {
        log_printf( &logger, " TAG UID: " );
        for ( uint8_t cnt = 0; cnt < tag_uid_len; cnt++ )
        {
            log_printf( &logger, "0x%.2X ", ( uint16_t ) tag_uid[ cnt ] );
        }
        log_printf( &logger, "\r\n----------------------------------\r\n" );
        Delay_ms ( 500 );
    }
}

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;
}

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