Intermediate
30 min

Experience ultra-fast CAN connectivity with TCAN4550 and STM32F091RC

Lightning-fast communication

CAN FD 6 Click with Nucleo-64 with STM32F091RC MCU

Published Feb 26, 2024

Click board™

CAN FD 6 Click

Dev Board

Nucleo-64 with STM32F091RC MCU

Compiler

NECTO Studio

MCU

STM32F091RC

Engineered for high-speed excellence, our CAN FD transceiver delivers unmatched performance in automotive and industrial systems

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Hardware Overview

How does it work?

CAN FD 6 Click is based on the TCAN4550, a CAN transceiver that supports CAN and CAN FD protocols and provides an interface between the CAN bus and the CAN protocol controller up to 5 megabits per second (Mbps) from Texas Instruments. It is characterized by high-bandwidth and data-rate flexibility, provides an SPI interface between the CAN bus and the system processor, and supports wake-up features local and bus wake using the CAN bus. The device includes many protection features providing CAN bus robustness, including fail-safe mode, internal dominant state timeout, and wide bus operating range. The TCAN4550 has one pin for waking the device from Sleep mode. This pin is connected to an external button labeled WAKE and the PWM pin of the mikroBUS™ socket labeled WKP to generate a local Wake-Up function. A Wake-Up event on the CAN bus switches the inhibit output pin INH to the high level. The INH pin provides an internal switch towards the battery supply voltage and controls external voltage regulators, the MCP1804 from

Microchip. Through SMD jumpers labeled as 3V3JMP and 5VJMP, the LDO's output voltages can power up the mikroBUS™ 3.3V and 5V power rails. However, it should be noted that Mikroe does not advise powering up their systems this way. That is why these jumpers are left unpopulated by default. CAN FD 6 Click communicates with MCU using a standard SPI interface supporting clock rates up to 18MHz to transmit and reception CAN frames. With an additional 40MHz crystal, the TCAN4550 can meet CAN FD rates up to 5 Mbps data rates to support higher data throughput and operates from a 6V to 24V external power supply header on the board's right side. This feature makes the TCAN4550 device ideal for many applications, including automotive ones. This Click board™ comes equipped with the industry-standard DB-9 connector, making interfacing with the CAN bus simple and easy. Besides, the user can connect the CAN signals directly through the CAN External header on the board's left edge. In addition to these features, the TCAN4550 uses

several GPIO pins connected to the mikroBUS™ socket. The RST pin, the mikroBUS™, can perform the Hardware Reset function, which resets the device to the default settings and puts it into standby mode. This feature can also be achieved through the onboard push-button labeled as RST. Next to these pins, the ATA6571 uses the WKR pin as a dedicated wake-up request pin from a bus wake request and the INT pin as an interrupt feature routed on the AN and INT pin of the mikroBUS™ socket. The user can also use GPIO pins from the header on the board's right side for interrupt purposes. This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VIO SEL jumper. It allows both 3.3V and 5V capable MCUs to use the UART communication lines properly. However, the 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.

CAN FD 6 Click hardware overview image

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.

Nucleo 64 with STM32F091RC MCU double side image

Microcontroller Overview

MCU Card / MCU

default

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.

Click Shield for Nucleo-64 accessories 1 image

DB9 Cable Female-to-Female (2m) cable is essential for establishing dependable serial data connections between devices. With its DB9 female connectors on both ends, this cable enables a seamless link between various equipment, such as computers, routers, switches, and other serial devices. Measuring 2 meters in length, it offers flexibility in arranging your setup without compromising data transmission quality. Crafted with precision, this cable ensures consistent and reliable data exchange, making it suitable for industrial applications, office environments, and home setups. Whether configuring networking equipment, accessing console ports, or utilizing serial peripherals, this cable's durable construction and robust connectors guarantee a stable connection. Simplify your data communication needs with the 2m DB9 female-to-female cable, an efficient solution designed to meet your serial connectivity requirements easily and efficiently.

CAN FD 6 Click accessories image

Used MCU Pins

mikroBUS™ mapper

Wake Request
PC0
AN
Reset
PC12
RST
SPI Chip Select
PB12
CS
SPI Clock
PB3
SCK
SPI Data OUT
PB4
MISO
SPI Data IN
PB5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Wake Up
PC8
PWM
Interrupt
PC14
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

CAN FD 6 Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-64 accessories 1 image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32F091RC MCU as your development board.

Click Shield for Nucleo-64 accessories 1 image hardware assembly
Nucleo 64 with STM32F401RE MCU front image hardware assembly
LTE IoT 5 Click front image hardware assembly
Prog-cut hardware assembly
LTE IoT 5 Click complete accessories setup image hardware assembly
Nucleo-64 with STM32XXX MCU Access MB 1 Mini B Conn - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output via Debug Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for CAN FD 6 Click driver.

Key functions:

  • canfd6_mcan_write_txbuffer - This function will write a CAN message to a specified TX buffer that can be transmitted at a later time with the transmit buffer contents function

  • canfd6_mcan_transmit_buffer_contents - This function writes the specified buffer index bit value into the TXBAR register to request a message to send

  • canfd6_mcan_read_nextfifo - This function will read the next MCAN FIFO element specified and return the corresponding header information and data payload.

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 CANFD6 Click example
 *
 * # Description
 * This application presents the capabilities of the
 * CAN FD 6 click board. The board can be used both
 * as a receiver and a transmitter. Use def directive
 * to define the receive or transmit app.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * The app starts by initializing the UART LOG and
 * SPI drivers. The default cfg function performs the
 * mandatory settings of the device. The user's default
 * configuration can be modified ( for more information
 * about device configuration, check the datasheet ).
 * Additionally, the app writes two messages to the FIFO
 * buffer and sends them if the transmit buffer content
 * event is triggered.
 *
 * ## Application Task
 * Depending on the defined app option, the application
 * task performs the following procedure. If the transmitter
 * is preferred, the application task triggers the transmit
 * buffer contents event of the first message and, later on,
 * the second message. On the other hand, the receiver waits
 * for the CAN FD interrupt, where the payload is read along
 * with the header ID.
 *
 * @author Stefan Nikolic
 *
 */

#include "board.h"
#include "log.h"
#include "canfd6.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

#define CANFD6_FIRST_MSG                        0
#define CANFD6_SECOND_MSG                       1

static canfd6_t canfd6;
static log_t logger;

void application_init ( void ) {
    log_cfg_t log_cfg;        /**< Logger config object. */
    canfd6_cfg_t canfd6_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.
    canfd6_cfg_setup( &canfd6_cfg );
    CANFD6_MAP_MIKROBUS( canfd6_cfg, MIKROBUS_1 );
    err_t init_flag = canfd6_init( &canfd6, &canfd6_cfg );
    if ( init_flag == SPI_MASTER_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    canfd6_default_cfg( &canfd6 );
    Delay_ms( 100 );
#ifdef DEMO_APP_TRANSMITTER
    canfd6_mcan_tx_header_t canfd6_header = { 0 };
    uint8_t data_send_buf[ 64 ] = { 0 };
    strcpy ( data_send_buf, "MIKROE" );
    canfd6_header.DLC = CANFD6_MCAN_DLC_6B;
    canfd6_header.ID = 0x123;
    canfd6_header.FDF = 1;
    canfd6_header.BRS = 1;
    canfd6_header.EFC = 0;
    canfd6_header.MM  = 0;
    canfd6_header.RTR = 0;
    canfd6_header.XTD = 0;
    canfd6_header.ESI = 0;
    canfd6_mcan_write_txbuffer( &canfd6, CANFD6_FIRST_MSG, &canfd6_header, data_send_buf );

    strcpy ( data_send_buf, "CAN FD 6 click board" );
    canfd6_header.DLC = CANFD6_MCAN_DLC_20B;
    canfd6_header.ID = 0x456;
    canfd6_header.FDF = 1;
    canfd6_header.BRS = 1;
    canfd6_header.EFC = 0;
    canfd6_header.MM  = 0;
    canfd6_header.RTR = 0;
    canfd6_header.XTD = 0;
    canfd6_header.ESI = 0;
    canfd6_mcan_write_txbuffer( &canfd6, CANFD6_SECOND_MSG, &canfd6_header, data_send_buf );
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    log_info( &logger, " Application Task " );
}

void application_task ( void ) {
#ifdef DEMO_APP_TRANSMITTER
    log_printf( &logger, " Transmit first message\r\n" );
    canfd6_mcan_transmit_buffer_contents( &canfd6, CANFD6_FIRST_MSG );
    Delay_ms( 2000 );
    log_printf( &logger, " Transmit second message\r\n" );
    canfd6_mcan_transmit_buffer_contents( &canfd6, CANFD6_SECOND_MSG );
    Delay_ms( 2000 );
#else
    uint8_t cnt = 0;
    if ( !canfd6_get_int_pin( &canfd6 ) ) {
        canfd6_device_interrupts_t canfd6_dev_ir = { 0 };
        canfd6_mcan_interrupts_t canfd6_mcan_ir = { 0 };
        canfd6_device_read_interrupts( &canfd6, &canfd6_dev_ir );
        canfd6_mcan_read_interrupts( &canfd6, &canfd6_mcan_ir );

        if ( canfd6_dev_ir.SPIERR ) {
            canfd6_device_clear_spierr( &canfd6 );
        }

        if ( canfd6_mcan_ir.RF0N ) {
            canfd6_mcan_rx_header_t canfd6_msg_header = { 0 };
            uint8_t num_bytes = 0;
            uint8_t data_payload[ 64 ] = { 0 };

            canfd6_mcan_clear_interrupts( &canfd6, &canfd6_mcan_ir );

            num_bytes = canfd6_mcan_read_nextfifo( &canfd6, CANFD6_RXFIFO0, &canfd6_msg_header, data_payload );
            
            log_printf( &logger, " Message received ID[ 0x%X ]: ", canfd6_msg_header.ID );

            while ( cnt < 64 ) {
                if ( data_payload[ cnt ] ) {
                    log_printf( &logger, "%c", data_payload[ cnt ] );
                    cnt++;
                } else {
                    log_printf( &logger, "\r\n" );
                    cnt = 64;
                }
            }
        }
    }
#endif
}

void main ( void ) {
    application_init( );

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

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

Additional Support

Resources

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