Redefine automotive communication with HS CAN via MCP251863 and STM32L442KC
Where data races at lightning speed
Published Aug 06, 2023
Click board™
MCP251863 Click
Dev Board
Fusion for ARM v8
Compiler
NECTO Studio
MCU
STM32L442KC
Unifying speed and reliability, our high-speed CAN FD transceiver establishes unprecedented standards in automotive diagnostic applications
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Hardware Overview
How does it work?
MCP251863 Click is based on the MCP251863, an IC representing a compact solution containing a CAN FD controller with an SPI interface and a high-speed CAN transceiver from Microchip. The high-speed CAN transceiver provides a physical connection with the CAN bus, while the CAN controller represents an interface between the MCU and the transceiver. The role of the CAN controller is to provide arbitration, message framing, message validation, error detection, message filtering, and more. Among all other tasks, it offers formatted CAN data for the application layer running on the host MCU. The MCP251863 communicates with MCU using the SPI interface, allowing communication speeds up to 5Mbps and supporting Normal and Standby operational modes. Normal mode is engaged when the STB pin, routed on the AN pin of the mikroBUS™ socket, is at the logic low level while its transmit pin is held to a high logic level. While in the Normal mode, the data can be sent and received via the CAN H/L bus lines. The mode
selection can be performed by positioning the SMD jumper labeled as STBY to an appropriate position marked as STBY or ON. In Standby mode, if the STBY jumper is set to the STBY position, the user has the option of activating the Standby mode in two ways, where the selection is made by positioning the SMD jumper labeled as STBY SEL to an appropriate position marked as STBY or INT0. This way, the Standby mode can be activated via the STB pin from the mikroBUS™ socket or by the MCP251863 interrupt signal IN0 routed to the TX pin of the mikroBUS™ socket (the IN0 pin can also be used to alert the MCU about the TX events). In addition, this Click board™ also uses several pins of the mikroBUS™ socket. The CLK pin from the MCP251863 routed to the PWM pin of the mikroBUS™ socket can provide the clock output for the host MCU or represent the start of the frame signal. It is derived from the input clock generated by the onboard chip oscillators, where the onboard SMD jumpers allow frequency selection between 20MHz and 40MHz.
Besides, it also uses two interrupt pins, INT and INT1, routed to the INT and RX pins of the mikroBUS™ socket, respectively. While the INT pin is always an interrupt pin used to alert the MCU of the enabled interrupt event, the INT1 pin alerts the MCU about the RX events (if these interrupts are enabled). In addition, the user can connect the external TX/RX signals to the CAN FD transceiver and CAN bus signals directly through the onboard headers on the left and right sides of the board. This Click board™ comes equipped with the standard DB-9 connector, making interfacing with the CAN bus simple and easy. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VIO 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
Fusion for ARM 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 ARM® Cortex®-M based MCUs 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 ARM v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the Fusion for ARM 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 ARM 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.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
ARM Cortex-M4
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
32
RAM (Bytes)
65536
You complete me!
Accessories
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.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Fusion for ARM v8 as your development board.
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.
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.
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".
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.
Software Support
Library Description
This library contains API for MCP251863 Click driver.
Key functions:
mcp251863_transmit_message- Transmits the desired message and checks is message successfully sentmcp251863_receive_message- Receives the message and checks is message successfully receivedmcp251863_operation_mode_select- Function for select operation mode
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 MCP251863 Click example
*
* # Description
* This example demonstrates the use of an MCP251863 click board by showing
* the communication between the two click boards configured as a receiver and transmitter.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and logger, performs the click default configuration and
* displays the selected application mode.
*
* ## Application Task
* Depending on the selected mode, it sends a desired message using CAN protocol or
* reads all the received data and displays them on the USB UART.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "mcp251863.h"
// #define DEMO_APP_TRANSMITTER // Uncomment this line to switch to the transmitter mode
#define DEMO_TEXT_MESSAGE "MikroE"
static mcp251863_t mcp251863;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
mcp251863_cfg_t mcp251863_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.
mcp251863_cfg_setup( &mcp251863_cfg );
MCP251863_MAP_MIKROBUS( mcp251863_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == mcp251863_init( &mcp251863, &mcp251863_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( MCP251863_ERROR == mcp251863_default_cfg ( &mcp251863 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
#ifdef DEMO_APP_TRANSMITTER
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
if ( MCP251863_OK == mcp251863_transmit_message( &mcp251863, DEMO_TEXT_MESSAGE, strlen( DEMO_TEXT_MESSAGE ) ) )
{
log_printf( &logger, " The message \"%s\" has been sent!\r\n", ( char * ) DEMO_TEXT_MESSAGE );
}
Delay_ms( 2000 );
#else
uint8_t data_buf[ 256 ] = { 0 };
uint16_t data_len = 0;
if ( MCP251863_OK == mcp251863_receive_message( &mcp251863, data_buf, &data_len ) )
{
log_printf( &logger, " A new message has received: \"" );
for ( uint16_t cnt = 0; cnt < data_len; cnt++ )
{
log_printf( &logger, "%c", data_buf[ cnt ] );
}
log_printf( &logger, "\"\r\n" );
}
#endif
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
