Beginner
10 min

Keep CAN communication secure with MAX14882 and PIC32MZ2048EFH100

Enhance the reliability and performance of the CAN bus in challenging environments

CAN Isolator 3 Click with Flip&Click PIC32MZ

Published Dec 09, 2023

Click board™

CAN Isolator 3 Click

Dev. board

Flip&Click PIC32MZ

Compiler

NECTO Studio

MCU

PIC32MZ2048EFH100

Provide protection from overvoltage transients between the CAN bus cable network and the systems connected to it

A

A

Hardware Overview

How does it work?

CAN Isolator 3 Click is based on MAX14882, an isolated CAN transceiver with an integrated transformer driver from Analog Devices. Its features include a wide supply voltage range for the CAN controller interface (3V – 5V), field bus polarity control (POL), an integrated transformer driver for power transfer to the bus side, and an integrated LDO for powering the CAN bus side. The CAN bus controller exceeds the ISO 11898 specifications requirement of -2V to +7V with ±25V receiver input common-mode range. Additionally, the CANH and CANL IOs are fault tolerant up to ±54V and protected from electronic discharge (ESD) up to ±15KV to GNDB on the bus side. CAN

Isolator 3 Click is equipped with CAN and VISO terminals, where the VISO terminal can be a bus-side power input or an LDO power output terminal. If used as an LDO power output, you can count up to 5V of VDDB voltage on this terminal. You can select the input/output direction over the VISO DIR jumper, where the isolated voltage as output (OUT) is set by default. In this default configuration, the reinforced insulation module can supply to the VISO terminal 3.3V or 5V, depending on the selected voltage on the VCC SEL jumper, as the 3.3V is selected by default. CAN Isolator 3 Click uses a standard UART serial interface to communicate with the host MCU over

commonly used UART RX and TX pins. The RX and TX are also available on a separate header for testing purposes. The polarity of the CAN controller can be set over the POL pin with a LOW logic state for normal CANH and CANL operation and HIGH to swap the functions of the CANH and CANL. 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.

CAN Isolator 3 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
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
CAN Polarity
RC14
PWM
NC
NC
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

CAN Isolator 3 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 CAN Isolator 3 Click driver.

Key functions:

  • canisolator3_generic_write - CAN Isolator 3 data writing function.

  • canisolator3_generic_read - CAN Isolator 3 data reading function.

  • canisolator3_set_pol_pin - CAN Isolator 3 set polarity 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 CAN Isolator 3 Click Example.
 *
 * # Description
 * This example writes and reads and processes data from CAN Isolator 3 Click.
 * The library also includes a function for selection of the output polarity.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the Click default configuration.
 *
 * ## Application Task
 * This example contains Transmitter/Receiver task depending on uncommented code.
 * Receiver logs each received byte to the UART for data logging,
 * while the transmitter sends messages every 2 seconds.
 *
 * ## Additional Function
 * - static err_t canisolator3_process ( canisolator3_t *ctx )
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "canisolator3.h"

#define PROCESS_BUFFER_SIZE 200
#define TX_MESSAGE "CAN Isolator 3 Click \r\n"

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

static canisolator3_t canisolator3;
static log_t logger;

static uint8_t app_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
static int32_t app_buf_len = 0;

/**
 * @brief CAN Isolator 3 data reading function.
 * @details This function reads data from device and concatenates data to application buffer. 
 * @param[in] ctx : Click context object.
 * See #canisolator3_t object definition for detailed explanation.
 * @return @li @c  0 - Read some data.
 *         @li @c -1 - Nothing is read.
 * See #err_t definition for detailed explanation.
 * @note None.
 */
static err_t canisolator3_process ( canisolator3_t *ctx );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    canisolator3_cfg_t canisolator3_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.
    canisolator3_cfg_setup( &canisolator3_cfg );
    CANISOLATOR3_MAP_MIKROBUS( canisolator3_cfg, MIKROBUS_1 );
    if ( UART_ERROR == canisolator3_init( &canisolator3, &canisolator3_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    canisolator3_default_cfg ( &canisolator3 );
    
#ifdef DEMO_APP_TRANSMITTER
    log_info( &logger, "---- Transmitter mode ----" );
#else
    log_info( &logger, "---- Receiver mode ----" );
#endif 
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
#ifdef DEMO_APP_TRANSMITTER
    canisolator3_generic_write( &canisolator3, TX_MESSAGE, strlen( TX_MESSAGE ) );
    log_info( &logger, "---- Data sent ----" );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
#else
    canisolator3_process( &canisolator3 );
#endif
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

static err_t canisolator3_process ( canisolator3_t *ctx ) 
{
    uint32_t rx_size;
    char rx_buf[ PROCESS_BUFFER_SIZE ] = { 0 };
    rx_size = canisolator3_generic_read( &canisolator3, rx_buf, PROCESS_BUFFER_SIZE );
    if ( rx_size > 0 ) 
    {
        log_printf( &logger, "%s", rx_buf );
        return CANISOLATOR3_OK;
    }
    return CANISOLATOR3_ERROR;
}

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

Additional Support

Resources

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