Intermediate
30 min

Enable instant data sharing between devices using PN7150 and ATmega644

NFC: The secret ingredient behind smarter, faster living

NFC 2 Click with EasyAVR v7

Published Oct 18, 2023

Click board™

NFC 2 Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega644

Unleash the power of NFC and explore the boundless innovations and convenience it brings to your digital life, from instant sharing to secure transactions

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Hardware Overview

How does it work?

NFC 2 Click is based on the PN7150, a high-performance full NFC solution with integrated firmware and I2C interface designed for contactless communication at 13.56 MHz from NXP Semiconductor. This board fully complies with NFC Forum specifications, which means that you will be able to use the full potential of NFC. It is the ideal solution for rapidly integrating NFC technology in any application, especially those running O/S environments like Linux and Android. It reduces size and cost thanks to embedded NFC firmware providing all NFC protocols as a pre-integrated feature and ultra-low power consumption. The PN7150 embeds a microcontroller core ARM Cortex-M0 loaded with the integrated firmware. It provides an easy integration and validation cycle as all the NFC real-time constraints, protocols, and device discovery are handled internally. The host can configure the PN7150 to notify for a card or peer detection

and start communicating with them. The core microcontroller chip of the PN7150 can run without any external clock (based on an internal oscillator). However, the 13.56MHz RF field carrier accuracy requirements are not compatible with using an internal oscillator. The PN7150 has an external crystal oscillator connected to its XTAL pins. It also has four power states: Monitor, Hard Power Down (HPD), Standby, and Active. The PN7150 will continuously switch between different power states at the application level to optimize the current consumption. The PN7150 is designed to allow the host controller to have full control over its operation, thus, of the power consumption of the PN7150 and the possibility to restrict parts of the PN7150 functionality. More information about these modes user can be found in the attached datasheet. NFC 2 Click communicates with MCU using the standard I2C 2-Wire interface with a clock frequency of up to 100kHz in the Standard,

up to 400kHz in the Fast, and up to 3.4MHz in the High-Speed Mode. The PN7150 also allows the choice of the least significant bit (LSB) of its I2C slave address by positioning SMD jumpers labeled as ADDR SEL to an appropriate position marked as 0 and 1. To enable and ensure data flow control between PN7150 and the host controller, a dedicated interrupt line labeled INT is provided so that the Active state is programmable. It also contains a Reset function and the RF antenna used to communicate over RF with a Tag (Card), Reader/Writer, or Peer device. 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.

NFC 2 Click top side image
NFC 2 Click bottom side image

Features overview

Development board

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block for the development board. It can use a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B)

connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets which cover a wide range of 16-bit AVR MCUs. EasyAVR v7 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

EasyAVR v7 horizontal image

Microcontroller Overview

MCU Card / MCU

ATmega644

Architecture

AVR

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

4096

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
PA6
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PD2
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PC0
SCL
I2C Data
PC1
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

NFC 2 Click Schematic schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyAVR v7 as your development board.

EasyAVR v7 front image hardware assembly
GNSS2 Click front image hardware assembly
EasyAVR v7 Access DIP MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware 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 2 Click driver.

Key functions:

  • nfc2_hw_reset - HW reset function.

  • nfc2_core_set_protocol_config - Set protocol configuration function.

  • nfc2_cmd_card_disconnected - Card disconnected command function.

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 NFC2 Click example
 *
 * # Description
 * This is an example which demonstrates the usage of NFC 2 Click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization driver enables - I2C,
 * hw reset, reseteting and initialize core, disabling standby mode, 
 * starting test procedure, set configuration and start discovery, also write log.
 *
 * ## Application Task
 * NFC 2 Click board can be used for detection of RFiD tag
 * and displays it's value via USART terminal.
 * All data logs write on USB uart changes for every 1 sec.
 *
 * Additional Functions :
 *  -void display_packet ( control_packet_t *ctrl_pck ) - Display packet log data.
 *  -void display_nfc_data ( control_packet_t *ctrl_pck ) - Display packet log data.
 *  -void nfc2_read_nfc_data ( nfc2_t *ctx, control_packet_t *ctrl_pck ) - Read nfc data function.
 *  -void nfc2_test_antenna ( nfc2_t *ctx, control_packet_t *ctrl_pck ) - Testing Antenna function.
 * 
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "nfc2.h"

static nfc2_t nfc2;
static log_t logger;
uint8_t n_cnt;

control_packet_t ctrl_pck_data;

/**
 * @brief NFC 2 display packet function.
 * @details This function displays data values.
 */
void display_packet ( control_packet_t *ctrl_pck );

/**
 * @brief NFC 2 display nfc data function.
 * @details This function displays nfc data values.
 */
void display_nfc_data ( control_packet_t *ctrl_pck );

/**
 * @brief NFC 2 read nfc data function.
 * @details This function reads nfc data and displays data.
 */
void nfc2_read_nfc_data ( nfc2_t *ctx, control_packet_t *ctrl_pck );

/**
 * @brief NFC 2  test antena function.
 * @details This function tests antenna and displays data.
 */
void nfc2_test_antenna ( nfc2_t *ctx, control_packet_t *ctrl_pck );

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    nfc2_cfg_t nfc2_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.
    nfc2_cfg_setup( &nfc2_cfg );
    NFC2_MAP_MIKROBUS( nfc2_cfg, MIKROBUS_1 );
    err_t init_flag = nfc2_init( &nfc2, &nfc2_cfg );
    if ( I2C_MASTER_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    log_printf( &logger, "        HW Reset       \r\n" );
    nfc2_hw_reset( &nfc2 );
    Delay_ms( 100 );

    log_printf( &logger, "-----------------------\r\n" );
    log_printf( &logger, " Reset and Init. Core  \r\n" );
    nfc2_cmd_core_reset( &nfc2 );
    Delay_ms( 100 );

    nfc2_read_ctrl_packet_data( &nfc2, &ctrl_pck_data );
    Delay_ms( 100 );

    nfc2_cmd_core_init( &nfc2 );
    Delay_ms( 100 );

    nfc2_read_ctrl_packet_data( &nfc2, &ctrl_pck_data );
    Delay_ms( 100 );
    display_packet( &ctrl_pck_data );

    while ( nfc2_check_irq( &nfc2 ) == NFC2_IRQ_STATE_HIGH );

    log_printf( &logger, "-----------------------\r\n" );
    log_printf( &logger, " Disabling Standby Mode \r\n" );
    nfc2_cmd_disable_standby_mode( &nfc2 );
    Delay_ms( 100 );

    nfc2_read_ctrl_packet_data( &nfc2, &ctrl_pck_data );
    Delay_ms( 100 );
    display_packet( &ctrl_pck_data );

    nfc2_test_antenna( &nfc2, &ctrl_pck_data );

    log_printf( &logger, "-----------------------\r\n" );
    log_printf( &logger, "Starting Test Procedure\r\n" );
    nfc2_cmd_test_procedure( &nfc2 );
    Delay_ms( 100 );

    nfc2_read_ctrl_packet_data( &nfc2, &ctrl_pck_data );
    Delay_ms( 100 );
    display_packet( &ctrl_pck_data );

    nfc2_hw_reset( &nfc2 );
    Delay_ms( 100 );

    log_printf( &logger, "-----------------------\r\n" );
    log_printf( &logger, "       NFC Config.     \r\n" );
    nfc2_default_cfg ( &nfc2, &ctrl_pck_data );

    log_printf( &logger, "-----------------------\r\n" );
    log_printf( &logger, "     Discovery Start   \r\n" );
    nfc2_cmd_start_discovery( &nfc2 );
    Delay_ms( 100 );

    nfc2_read_ctrl_packet_data( &nfc2, &ctrl_pck_data );
    Delay_ms( 100 );
    display_packet( &ctrl_pck_data );

    log_printf( &logger, "-----------------------\r\n" );
    log_printf( &logger, "-------- START --------\r\n" );
    log_printf( &logger, "-----------------------\r\n" );
    Delay_ms( 500 );

    log_info( &logger, " Application Task " );
}

void application_task ( void ) {
    while ( nfc2_check_irq( &nfc2 ) == NFC2_IRQ_STATE_HIGH ) {
        nfc2_read_nfc_data ( &nfc2, &ctrl_pck_data );
    }

    while ( nfc2_check_irq( &nfc2 ) == NFC2_IRQ_STATE_LOW );

    log_printf( &logger, "-----------------------\r\n" );
    Delay_ms( 1000 );
}

void main ( void ) {
    application_init( );

    for ( ; ; ) {
        application_task( );
    }
}

void display_packet ( control_packet_t *ctrl_pck ) {
    log_printf( &logger, "- - - - - - - - - - - -\r\n" );
    log_printf( &logger, " Message Type   = %d\r\n", ( uint16_t ) ctrl_pck->message_type );
    log_printf( &logger, " Pck Bound Flag = %d\r\n", ( uint16_t ) ctrl_pck->pck_bound_flag );
    log_printf( &logger, " Group Ident    = %d\r\n", ( uint16_t ) ctrl_pck->group_ident );
    log_printf( &logger, " Opcode Ident   = %d\r\n", ( uint16_t ) ctrl_pck->opcode_ident );
    log_printf( &logger, " Payload Length = %d\r\n", ( uint16_t ) ctrl_pck->payload_length );
    log_printf( &logger, "- - - - - - - - - - - -\r\n" );

    for ( n_cnt = 0; n_cnt < ctrl_pck_data.payload_length; n_cnt++ ) {
        log_printf( &logger, " Payload[ %.2d ]  = 0x%.2X\r\n", ( uint16_t ) n_cnt, ( uint16_t ) ( uint16_t ) ctrl_pck_data.payload[ n_cnt ]  );
    }

    log_printf( &logger, "- - - - - - - - - - - -\r\n" );
    memset( ctrl_pck_data.payload, 0x00, 255 );
}

void display_nfc_data ( control_packet_t *ctrl_pck ) {
    log_printf( &logger, "- - - - - - - - - - - -\r\n");
    log_printf( &logger, " Read Block:\r\n");

    for ( n_cnt = 1; n_cnt < ctrl_pck->payload_length - 2; n_cnt++ ) {
        log_printf( &logger, "\t 0x%.2X \r\n", ( uint16_t ) ctrl_pck->payload[ n_cnt ] );
    }
    log_printf( &logger, "\t 0x%.2X \r\n", ( uint16_t ) ctrl_pck->payload[ ctrl_pck->payload_length - 2 ] );

    log_printf( &logger, "- - - - - - - - - - - -\r\n" );
    memset( ctrl_pck->payload, 0x00, 255 );
}

void nfc2_read_nfc_data ( nfc2_t *ctx, control_packet_t *ctrl_pck ){
    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 100 );

    nfc2_activate_rmt_mifare_card( ctx );
    Delay_ms( 100 );
    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 10 );

    while ( nfc2_check_irq( ctx ) == NFC2_IRQ_STATE_LOW );

    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    nfc2_cmd_authenticate_sector( ctx, 0x30 );
    Delay_ms( 100 );
    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 10 );

    while ( nfc2_check_irq( ctx ) == NFC2_IRQ_STATE_LOW );

    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    display_nfc_data( ctrl_pck );
    log_printf( &logger, "    Disconnect Card    \r\n" );
    nfc2_cmd_card_disconnected( ctx );
    Delay_ms( 10 );
    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 10 );

    while ( nfc2_check_irq( ctx ) == NFC2_IRQ_STATE_LOW );

    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 100 );
}

void nfc2_test_antenna ( nfc2_t *ctx, control_packet_t *ctrl_pck ) {
    log_printf( &logger, "-----------------------\r\n" );
    log_printf( &logger, "    Testing Antenna    " );
    nfc2_cmd_antenna_test( ctx, 0x01 );
    Delay_ms( 100 );

    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 100 );

    nfc2_cmd_antenna_test( ctx, 0x07 );
    Delay_ms( 100 );
    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 100 );

    nfc2_cmd_antenna_test( ctx, 0x0F );
    Delay_ms( 100 );
    nfc2_read_ctrl_packet_data( ctx, ctrl_pck );
    Delay_ms( 100 );
    display_packet( ctrl_pck );
}
// ------------------------------------------------------------------------ END

Additional Support

Resources

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