Intermediate
30 min

Step into a new era of CXPI communication with BD41000AFJ-C and PIC32MZ2048EFH100

Transcending communication limits

CXPI Click with Flip&Click PIC32MZ

Published Aug 13, 2023

Click board™

CXPI Click

Dev. board

Flip&Click PIC32MZ

Compiler

NECTO Studio

MCU

PIC32MZ2048EFH100

Our advanced transceiver seamlessly integrates with CXPI networks, empowering efficient and reliable automotive communication for optimal data exchange in demanding environments

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Hardware Overview

How does it work?

CXPI Click is based on the BD41000AFJ-C, a transceiver for the Clock Extension Peripheral Interface (CXPI) communication from Rohm Semiconductor. The BD41000FJ-C complies with the CXPI standard established by JSAE (Society of Automotive Engineers of Japan), enabling highly responsive, reliable multiplex communication even in HMI systems, reducing vehicle weight and increasing fuel efficiency. The BD41000AFJ-C operates from 7V to 18V external power supply labeled as BAT and has several operating modes, each controlled by the CS pin of the mikroBUS™, BUS pin, and UART TX pin. It has built-in Power-OFF, Through, and RX Through other than CODEC Mode for power-saving control. Power-OFF Mode reduces power consumption by not supplying power to circuits other than necessary for Wake-Up pulse detection (BUS) and Wake-Up input

detection (TX). Through Mode does not process Coding/Decoding. It only directly drives signals from UART TX to BUS and from BUS to UART RX. RX Through Mode reverses RX output at each rising edge of BUS. CODEC Mode is the mode of CXPI communication. CS pin of the mikroBUS™ socket labeled as EN should be set high for the chip to enter CODEC Mode. The BD41000AFJ-C can achieve a quiescent 3uA (typ.) current, ensuring suitability with automotive applications. As a result, the battery load is minimized during non-operation, contributing to higher energy savings. Also, high ESD resistance (±8kV) makes achieving low-power, high-reliability CXPI communication possible. Besides, it has built-in fail-safe functions that suspend the output data upon detecting under-voltage or temperature abnormality. CXPI Click communicates

with MCU using the UART interface with a transmission speed range from 5kbps to 20kbps and commonly used UART RX and TX pins for data transfer. Also, it has three jumpers that allow the selection of CXPI transmitter mode on the MS pin of the BD41000AFJ-C to its appropriate position marked as Master or Slave. This can be performed by using the SMD jumpers labeled as MODE. Note that all the jumpers must be placed on the same side, or the Click board™ may become unresponsive. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC 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.

CXPI Click hardware overview image

Features overview

Development board

Flip&Click PIC32MZ is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller, the PIC32MZ2048EFH100 from Microchip, four mikroBUS™ sockets for Click board™ connectivity, two USB connectors, LED indicators, buttons, debugger/programmer connectors, and two headers compatible with Arduino-UNO pinout. Thanks to innovative manufacturing technology,

it allows you to build gadgets with unique functionalities and features quickly. Each part of the Flip&Click PIC32MZ development kit contains the components necessary for the most efficient operation of the same board. In addition, there is the possibility of choosing the Flip&Click PIC32MZ programming method, using the chipKIT bootloader (Arduino-style development environment) or our USB HID bootloader using mikroC, mikroBasic, and mikroPascal for PIC32. This kit includes a clean and regulated power supply block through the USB Type-C (USB-C) connector. All communication

methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, user-configurable buttons, and LED indicators. Flip&Click PIC32MZ development kit allows you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

Flip&Click PIC32MZ double image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
Enable
RA0
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Master Mode: Clock Input
RC14
PWM
Slave Mode: Clock Output
RD9
INT
UART TX
RE3
TX
UART RX
RG9
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

CXPI Click Schematic schematic

Step by step

Project assembly

Flip&Click PIC32MZ front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Flip&Click PIC32MZ as your development board.

Flip&Click PIC32MZ front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Flip&Click PIC32MZ MB1 Access - 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
Flip&Click PIC32MZ 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

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 CXPI Click driver.

Key functions:

  • cxpi_send_command - Send command

  • cxpi_set_pwm_pin_state - Set PWM pin state function

  • cxpi_set_through_mode - Set through mode 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 CXPI Click Example.
 *
 * # Description
 * This is an example that demonstrates the use of the CXPI Click board.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes UART driver.
 * In addition to this module is placed inside transmitter/receiver working mode
 * cappable of transmission/receive the data.
 *
 * ## Application Task
 * Transmitter/Receiver task depend on uncommented code
 * Receiver logging each received byte to the UART for data logging,
 * while transmitted send messages every 5 seconds.
 *
 * ## Additional Function
 * - static void cxpi_clear_current_rsp_buf ( void )
 * - static void cxpi_process ( void )
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "cxpi.h"

#define PROCESS_COUNTER 10
#define PROCESS_RX_BUFFER_SIZE 100
#define PROCESS_PARSER_BUFFER_SIZE 100

//#define DEMO_APP_RECEIVER
#define DEMO_APP_TRANSMITTER

static cxpi_t cxpi;
static log_t logger;

static char current_rsp_buf[ PROCESS_PARSER_BUFFER_SIZE ];
unsigned char demo_message[ 9 ] = { 'M', 'i', 'k', 'r', 'o', 'E', 13, 10, 0 };

/**
 * @brief CXPI clearing application buffer.
 * @details This function clears memory of application buffer and resets it's length and counter.
 */
static void cxpi_clear_current_rsp_buf ( void );

/**
 * @brief CXPI data reading function.
 * @details This function reads data from device and concatenates data to application buffer.
 */
static void cxpi_process ( void );

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    cxpi_cfg_t cxpi_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 );

    // Click initialization.

    cxpi_cfg_setup( &cxpi_cfg );
    CXPI_MAP_MIKROBUS( cxpi_cfg, MIKROBUS_1 );
    err_t init_flag  = cxpi_init( &cxpi, &cxpi_cfg );
    if ( UART_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    log_info( &logger, " Application Task " );
    cxpi_set_through_mode( &cxpi );

#ifdef DEMO_APP_TRANSMITTER
    log_printf( &logger, "------------------\r\n" );
    log_printf( &logger, "    Send data:    \r\n" );
    log_printf( &logger, "      MikroE      \r\n" );
    Delay_ms( 1000 );
#elif defined DEMO_APP_RECEIVER
    log_printf( &logger, "------------------\r\n" );
    log_printf( &logger, "   Receive data  \r\n" );
    Delay_ms( 2000 );
#else
    # error PLEASE SELECT TRANSMIT OR RECEIVE MODE!!!
#endif

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

void application_task ( void ) {
#ifdef DEMO_APP_TRANSMITTER
    cxpi_send_command( &cxpi, &demo_message[ 0 ] );
    log_printf( &logger, " Sent data : %s",  &demo_message[ 0 ] );
    log_printf( &logger, "------------------\r\n" ); 
    Delay_ms( 5000 );
#elif defined DEMO_APP_RECEIVER
    cxpi_process( );
    if ( current_rsp_buf > 0 ) {
        log_printf( &logger, "%s", current_rsp_buf );
        cxpi_clear_current_rsp_buf( );
    }
#else
    # error PLEASE SELECT TRANSMIT OR RECEIVE MODE!!!
#endif
}

void main ( void ) {
    application_init( );

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

static void cxpi_clear_current_rsp_buf ( void ) {
    memset( current_rsp_buf, 0, PROCESS_PARSER_BUFFER_SIZE );
}

static void cxpi_process ( void ) {
    int16_t rsp_size;
    uint16_t rsp_cnt = 0;

    char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    uint8_t check_buf_cnt;
    uint8_t process_cnt = PROCESS_COUNTER;

    // Clear parser buffer
    memset( current_rsp_buf, 0 , PROCESS_PARSER_BUFFER_SIZE ); 

    while( process_cnt != 0 ) {
        rsp_size = cxpi_generic_read( &cxpi, &uart_rx_buffer, PROCESS_RX_BUFFER_SIZE );

        if ( rsp_size > 0 ) {
            // Validation of the received data
            for ( check_buf_cnt = 0; check_buf_cnt < rsp_size; check_buf_cnt++ ) {
                if ( uart_rx_buffer[ check_buf_cnt ] == 0 ) {
                    uart_rx_buffer[ check_buf_cnt ] = 13;
                }
            }
            // Storages data in parser buffer
            rsp_cnt += rsp_size;
            if ( rsp_cnt < PROCESS_PARSER_BUFFER_SIZE ) {
                strncat( current_rsp_buf, uart_rx_buffer, rsp_size );
            }

            // Clear RX buffer
            memset( uart_rx_buffer, 0, PROCESS_RX_BUFFER_SIZE );
        } else {
            process_cnt--;
            // Process delay 
            Delay_ms( 100 );
        }
    }
}

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

Additional Support

Resources

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