Intermediate
30 min
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Simplify user interactions by employing a fingerprint-based solution with 100018754 and STM32F427ZI

Seamless authentication

Fingerprint 4 Click with Fusion for STM32 v8

Published Aug 25, 2023

Click board™

Fingerprint 4 Click

Development board

Fusion for STM32 v8

Compiler

NECTO Studio

MCU

STM32F427ZI

This solution aims to provide real-time matching and validation of fingerprint patterns, establishing a seamless and robust authentication process

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Hardware Overview

How does it work?

Fingerprint 4 Click is based on the FPC BM-Lite module (100018754), a standalone, compact biometric fingerprint solution from Fingerprints with a robust fingerprint sensor, biometric processor, and on-board template storage ready to be used out-of-the-box. This Click board™ can be integrated into any application and controlled by a host MCU sending some basic commands for enrollment and verification via the selectable serial interface. The BM-Lite module is based on capacitive technology and utilizes a reflective measurement method. It acquires the fingerprint image from the fingerprint sensor. It stores them in the internal flash memory, which is pre-loaded with firmware from Fingerprints and used for all biometric operations and template storage.

The BM-Lite module, with a 160x160px sensor matrix, uses a 3D pixel sensing technology that can read virtually any finger, dry or wet, and brings together superior biometric performance and a high standard of integrated quality components to offer an embedded solution for increased security and enhanced user convenience. The module has a protective coating that protects against ±15kV ESD, scratches, and daily wear and tear impact. It is also waterproof, making it suitable for demanding industrial conditions and all-weather applications. Fingerprint 4 Click allows the UART interface with commonly used UART RX and TX pins, operating at 115200bps by default configuration, to transmit and exchange data with the host MCU or SPI interface with a maximum

frequency of 20MHz. The selection can be made by positioning SMD jumpers labeled as COMM SEL in an appropriate position. While using the SPI interface, users can use the data ready pin, marked IRQ and routed to the INT pin of the mikroBUS™ socket, to inform the host MCU about detecting a finger on the module and general reset function routed on the RST pin of the mikroBUS™ socket. 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.

Fingerprint 4 Click top side image
Fingerprint 4 Click bottom side image

Features overview

Development board

Fusion for STM32 v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different 32-bit ARM® Cortex®-M based MCUs from STMicroelectronics, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, Fusion for STM32 v8 provides a fluid and immersive working experience, allowing

access anywhere and under any circumstances at any time. Each part of the Fusion for STM32 v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. Fusion for STM32 v8 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.

Fusion for STM32 v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

2048

Silicon Vendor

STMicroelectronics

Pin count

144

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
PE11
RST
SPI Chip Select
PA4
CS
SPI Clock
PA5
SCK
SPI Data OUT
PA6
MISO
SPI Data IN
PB5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Data Ready
PD3
INT
UART TX
PB6
TX
UART RX
PB7
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Fingerprint 4 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Fusion for STM32 v8 as your development board.

Fusion for PIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
v8 SiBRAIN 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 image step 7 hardware assembly
Necto image step 8 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

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Fingerprint 4 Click driver.

Key functions:

  • fingerprint4_version - This function reads out version information from the device

  • fingerprint4_identify_finger - This function captures and identifies finger against existing templates in Flash storage

  • fingerprint4_wait_finger_not_present - This function waits until no finger is detected on the sensor

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * @file main.c
 * @brief Fingerprint 4 Click example
 *
 * # Description
 * This example demonstrates the use of the Fingerprint 4 click boards by registering 3 fingerprints and
 * then waiting until a finger is detected on the sensor and identifying if the fingerprint matches one of
 * those stored in the Flash storage.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and reads the sensor firmware version, then resets the sensor and removes all
 * stored fingerprint templates. After that it registers 3 new fingerprint templates and stores them in the Flash storage.
 * 
 * ## Application Task  
 * Waits until a finger is detected on the sensor, takes an image of the finger and checks if there's
 * a fingerprint in the library that matches the one it has just read. If it finds a match, a fingerprint template
 * ID will be displayed. All data is being logged on the USB UART where you can track the program flow.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "fingerprint4.h"

#define LOCATION_IN_FLASH               0   // Starting location or template ID where the fingerprints will be stored.
#define NUMBER_OF_FINGERPRINTS          3   // Number of fingerprints to register.

static fingerprint4_t fingerprint4;
static log_t logger;

/**
 * @brief Fingerprint 4 error check function.
 * @details This function checks the @b error_flag and displays the result appended to @b message 
 * on the USB UART.
 * @param[in] message : Prefix message of the error_flag result.
 * @param[in] error_flag : Error flag, return value of the functions.
 * @return None.
 * @note None.
 */
static void fingerprint4_error_check ( char *message, err_t error_flag );

/**
 * @brief Fingerprint 4 enroll fingerprint function.
 * @details This function enrolls a single fingerprint by taking 3 image captures. Each step will be logged on the USB UART
 * where you can track the function flow.
 * @param[in] ctx : Click context object.
 * See #fingerprint4_t object definition for detailed explanation.
 * @return @li @c  0 - Success,
 *         @li @c <0 - Error.
 * See #fingerprint4_return_value_t definition for detailed explanation.
 * @note None.
 */
static err_t fingerprint4_enroll_fingerprint ( fingerprint4_t *ctx );

/**
 * @brief Fingerprint 4 register fingerprints function.
 * @details This function registers a desired number of fingerprints starting from the selected template ID.
 * Each step will be logged on the USB UART where you can track the function flow.
 * @param[in] ctx : Click context object.
 * See #fingerprint4_t object definition for detailed explanation.
 * @param[in] template_id : Starting template ID of fingerprints to store to Flash.
 * @param[in] num_fpc : Number of fingerprints to register.
 * @return None.
 * @note None.
 */
static void fingerprint4_register_fingerprints ( fingerprint4_t *ctx, uint16_t template_id, uint8_t num_fpc );

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    fingerprint4_cfg_t fingerprint4_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.
    fingerprint4_cfg_setup( &fingerprint4_cfg );
    FINGERPRINT4_MAP_MIKROBUS( fingerprint4_cfg, MIKROBUS_1 );
    if ( FINGERPRINT4_RES_OK != fingerprint4_init( &fingerprint4, &fingerprint4_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    fingerprint4_reset_device ( &fingerprint4 );
    
    fingerprint4.phy_rx_timeout = FINGERPRINT4_DEFAULT_PHY_RX_TIMEOUT_MS;
    
    uint8_t version[ 50 ] = { 0 };
    if ( FINGERPRINT4_RES_OK == fingerprint4_version ( &fingerprint4, version, 50 ) )
    {
        log_printf( &logger, " FW version: %s\r\n", version );
        log_printf( &logger, "---------------------------------\r\n\n" );
    }
    
    fingerprint4_error_check( "Sensor reset", fingerprint4_sensor_reset ( &fingerprint4 ) );
    
    fingerprint4_error_check( "Remove all templates", fingerprint4_template_remove_all ( &fingerprint4 ) );
    
    fingerprint4_register_fingerprints ( &fingerprint4, LOCATION_IN_FLASH, NUMBER_OF_FINGERPRINTS );
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    uint16_t template_id;
    bool match;
    log_printf( &logger, " Put your finger on the sensor.\r\n" );
    err_t error_flag = fingerprint4_identify_finger ( &fingerprint4, FINGERPRINT4_INFINITE_TIMEOUT, &template_id, &match );
    if ( error_flag )
    {
        fingerprint4_error_check( "Identify finger", error_flag );
    }
    else
    {
        if ( match )
        {
            log_printf( &logger, " >>>>> Fingerprint MATCH - Template ID: %u <<<<<\r\n", template_id );
        }
        else
        {
            log_printf( &logger, " >>>>> NO MATCH in the library <<<<<\r\n" );
        }
    }
    log_printf( &logger, " Lift the finger of the sensor.\r\n" );
    fingerprint4_wait_finger_not_present ( &fingerprint4, FINGERPRINT4_INFINITE_TIMEOUT );
    log_printf( &logger, "---------------------------------\r\n\n" );
}

void main ( void )
{
    application_init( );

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

static void fingerprint4_error_check ( char *message, err_t error_flag )
{
    log_printf( &logger, " %s: ", message );
    if ( error_flag )
    {
        log_printf( &logger, "FAIL! [ERROR] Num: %ld\r\n", error_flag );
    }
    else
    {
        log_printf( &logger, "DONE!\r\n" );
    }
    log_printf( &logger, "---------------------------------\r\n\n" );
}

static void fingerprint4_register_fingerprints ( fingerprint4_t *ctx, uint16_t template_id, uint8_t num_fpc )
{
    err_t error_flag = FINGERPRINT4_RES_OK;
    uint8_t cnt = 1;
    while ( cnt <= num_fpc )
    {
        log_printf( &logger, " >>> Registering fingerprint %u of %u <<<\r\n", ( uint16_t ) cnt, 
                                                                              ( uint16_t ) num_fpc );
        error_flag = fingerprint4_enroll_fingerprint ( ctx );
        if ( error_flag )
        {
            fingerprint4_error_check( "Enroll finger", error_flag );
        }
        else
        {
            error_flag = fingerprint4_template_save ( &fingerprint4, template_id + cnt - 1 );
            if ( error_flag )
            {
                fingerprint4_error_check( "Template save", error_flag );
            }
            else
            {
                log_printf( &logger, " Fingerprint template ID: %u\r\n", template_id + cnt - 1 );
                log_printf( &logger, "---------------------------------\r\n\n" );
                cnt++;
            }
        }
    }
}

static err_t fingerprint4_enroll_fingerprint ( fingerprint4_t *ctx )
{
    err_t error_flag = FINGERPRINT4_RES_OK;
    bool enroll_done = false;
    // Enroll start
    error_flag = fingerprint4_send_cmd ( ctx, FINGERPRINT4_CMD_ENROLL, FINGERPRINT4_ARG_START );
    if ( error_flag )
    {
        fingerprint4_error_check( "Enroll start", error_flag );
        return error_flag;
    }
    uint8_t cnt = 1;
    while ( cnt <= FINGERPRINT4_NUM_IMAGES )
    {
        log_printf( &logger, " >>> Taking image %u of %u <<<\r\n", ( uint16_t ) cnt, 
                                                                   ( uint16_t ) FINGERPRINT4_NUM_IMAGES );
        log_printf( &logger, " Put your finger on the sensor.\r\n" );
        // Capture image
        uint32_t prev_timeout = ctx->phy_rx_timeout;
        ctx->phy_rx_timeout = FINGERPRINT4_INFINITE_TIMEOUT;
        error_flag = fingerprint4_send_cmd_arg ( ctx, FINGERPRINT4_CMD_CAPTURE, FINGERPRINT4_ARG_NONE, 
                                                 FINGERPRINT4_ARG_TIMEOUT, &ctx->phy_rx_timeout, sizeof ( ctx->phy_rx_timeout ) );
        ctx->phy_rx_timeout = prev_timeout;
        if ( error_flag ) 
        {
            fingerprint4_error_check( "Capture image", error_flag );
            continue;
        }
        // Enroll add
        error_flag = fingerprint4_send_cmd ( ctx, FINGERPRINT4_CMD_ENROLL, FINGERPRINT4_ARG_ADD );
        if ( error_flag ) 
        {
            fingerprint4_error_check( "Enroll add", error_flag );
            continue;
        }
        cnt++;
        uint32_t samples_remaining;
        fingerprint4_copy_arg ( ctx, FINGERPRINT4_ARG_COUNT, ( uint8_t * ) &samples_remaining, 4 );
        // Break enrolling if we collected enough correct images
        if ( !samples_remaining ) 
        {
            enroll_done = true;
            break;
        }
        log_printf( &logger, " Lift the finger of the sensor.\r\n" );
        log_printf( &logger, "---------------------------------\r\n" );
        fingerprint4_wait_finger_not_present ( ctx, FINGERPRINT4_INFINITE_TIMEOUT );
    }
    error_flag = fingerprint4_send_cmd ( ctx, FINGERPRINT4_CMD_ENROLL, FINGERPRINT4_ARG_FINISH );
    if ( error_flag )
    {
        fingerprint4_error_check( "Enroll finish", error_flag );
        return error_flag;
    }
    log_printf( &logger, " Lift the finger of the sensor.\r\n" );
    log_printf( &logger, "---------------------------------\r\n" );
    fingerprint4_wait_finger_not_present ( ctx, FINGERPRINT4_INFINITE_TIMEOUT );
    return ( !enroll_done ) ? FINGERPRINT4_RES_ERROR : error_flag;
}

// ------------------------------------------------------------------------ END

Additional Support

Resources