Beginner
10 min

Keep CAN communication secure with MAX14882 and PIC32MZ2048EFM100

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

CAN Isolator 3 Click with Curiosity PIC32 MZ EF

Published Dec 09, 2023

Click board™

CAN Isolator 3 Click

Dev Board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

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

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Curiosity PIC32MZ EF double side 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
RPE8
PWM
NC
NC
INT
UART TX
RPD10
TX
UART RX
RPD15
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

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Curiosity PIC32MZ EF front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Curiosity PIC32 MZ EF MB 1 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
Curiosity PIC32 MZ EF 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( 2000 );
#else
    canisolator3_process( &canisolator3 );
#endif
}

int main ( void ) 
{
    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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