Add RFID reader/writer capabilities to your project with CR95HF and STM32F091RC
RFID (Radio Frequency Identification) multi-protocol contactless transceiver
Published Feb 26, 2024
Click board™
RFid Click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Achieve communication with RFID tags and supports various applications such as tracking, security systems, and identification
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Hardware Overview
How does it work?
RFid Click is based on the CR95HF, a multi-protocol contactless transceiver from STMicroelectronics. This board supports ISO/IEC 14443 type A and B, ISO/IEC 15693, and ISO/IEC 18092 communication protocols (tags). In addition, it also supports the detection, reading, and writing of NFC forum type 1, 2, 3, and 4 tags with incorporated internal antenna. The CR95HF integrates an Analog Front End to provide the 13.56MHz Air Interface. It manages frame coding and decoding in Reader mode for standard applications such as near-field communication (NFC), proximity, and vicinity standards. The CR95HF has two operating modes: Wait for Event
(WFE) and Active Mode of operation. In Active mode, the CR95HF communicates actively with a tag or an external host. The WFE mode includes four low-consumption states: Power-up, Hibernate, Sleep, and Tag Detector, allowing the transceiver to switch from one mode to another. All states except Power-Up are software-accessible. While the CR95HF is in any of these, communication with the MCU is impossible. For normal communication, the transceiver must be woken up first. RFid Click can communicate with the host MCU using UART or SPI serial interfaces over the mikroBUS™ socket. This Click board™ comes with A and B jumpers with which the function of two multiplex pins is
selected. Depending on their position, the pins can be used as UART or interrupt (input and output) pins (interrupt by default). These jumpers must be set to the B position for use with the UART interface, thus losing the interrupt function pins. The SSSI0 and SSI1 pins serve for communication interface selection based on their logic states. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ 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 STM32F091RC 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-M0
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
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.
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
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32F091RC MCU as your development board.
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 RFID Click driver.
Key functions:
rfid_select_communication_interface- Select communication interfacerfid_get_tag_uid- Get RFID tag uid functionrfid_get_device_id- RFID get device id 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 RFID Click example
*
* # Description
* This example demonstrates the use of RFID 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, selects the communication interface and performs
* the click default configuration.
*
* ## Application Task
* If there's a tag detected, it reads its UID and displays it on USB UART.
*
* @note
* It is recommended to tie SSI_0, SSI_1 to VCC/GND at power-up, depending on
* the communication interface selection by A and B on-board jumpers.
* SSI_0 - UART: 0 SPI: 1
* SSI_1 - UART: 0 SPI: 0
*
* Only 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 "rfid.h"
static rfid_t rfid;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
rfid_cfg_t rfid_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 " );
Delay_ms( 100 );
// Click initialization.
rfid_cfg_setup( &rfid_cfg );
RFID_MAP_MIKROBUS( rfid_cfg, MIKROBUS_1 );
err_t error_flag = rfid_init( &rfid, &rfid_cfg );
if ( error_flag != RFID_OK )
{
log_error( &logger, " Please, run program again... " );
for ( ; ; );
}
log_printf( &logger, " Selecting communication interface... \r\n" );
error_flag = rfid_select_communication_interface ( &rfid, RFID_SPI );
if ( error_flag != RFID_OK )
{
log_error( &logger, " Please, run program again... " );
for ( ; ; );
}
log_printf( &logger, " Configuring the device... \r\n" );
error_flag = rfid_default_cfg ( &rfid );
if ( error_flag != RFID_OK )
{
log_error( &logger, " Please, run program again... " );
for ( ; ; );
}
log_printf( &logger, " The device has been configured! \r\n" );
}
void application_task ( void )
{
uint8_t tag_uid[ 20 ] = { 0 };
uint8_t tag_len = rfid_get_tag_uid( &rfid, RFID_ISO_14443A, tag_uid );
if ( tag_len > 0 )
{
log_printf( &logger, " TAG UID: " );
for ( uint8_t cnt = 0; cnt < tag_len; cnt++ )
{
log_printf( &logger, "0x%.2X ", ( uint16_t ) tag_uid[ cnt ] );
}
log_printf( &logger, "\r\n----------------------------------\r\n" );
Delay_ms( 1000 );
}
}
void main ( void )
{
application_init( );
for ( ; ; ) {
application_task( );
}
}
// ------------------------------------------------------------------------ END
