Design a more compact and cost-effective CAN solution with NCV7356 and PIC18F57Q43

Single wire CAN transceiver

Single Wire CAN Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

Single Wire CAN Click

Dev. board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Our single-wire CAN transceiver is designed to streamline communication in low-speed applications, reducing wiring complexity and achieving cost savings in automotive body control modules

Hardware Overview

How does it work?

Single Wire CAN Click is based on the NCV7356, a Single Wire CAN transceiver from ON Semiconductor, which operates from a supply voltage from 5V to 27V with a bus speed up to 40 kbps. It can access several modes such as Normal Mode with reduced dominant output voltage and reduced receiver input voltage, High-Speed, High Voltage Wake-Up, or Sleep Mode. The transmission bit rate in Normal communication is 33 Kbits/s, while a typical bit rate of 83 kbit/s is recommended for High-Speed communication. In Normal Transmission Mode, the Single Wire CAN Click supports controlled waveform rise and overshoot times, while the High−Speed Mode is only intended to be operational when the bus is attached to an off−board service node. The Single Wire CAN bus pin CANH comprises a pull−up

amplifier for driving this Click board™. The minimum output driver capability is 50 mA, but output shorts to the ground can reach 350 mA. Normal CANH output voltage is between 4.4 V and 5.1 V. These amplitudes increase to 9.9 V and 12.5 V for system selection in Wake−Up Mode. The bus Wake−Up from Sleep Input Voltage Threshold is between 6.6 V and 7.9 V, but to maintain normal communication, the threshold is 2.1 V. The CANH pin can also act as a bus read amplifier. The NCV7356D1R2G communicates with MCU using the UART interface at 9600 bps with commonly used UART RX and TX pins. It possesses additional functionality such as Operational Mode Selection MODE 0 and MODE 1 routed at RST and CS pins of the mikroBUS™, on whose selected logical states one of the four possible operational modes can be

selected. The transceiver provides a weak internal pulldown current on each of these pins, which causes the transceiver, on default, to enter sleep mode when not driven. Single Wire CAN Click can also re-enter the Sleep Mode if there is no mode change within typically 250 ms. This Click board™ communicates with MCU using the UART interface for the data transfer. The onboard SMD jumper labeled VCC SEL allows logic level voltage selection for interfacing with 3.3V and 5V MCUs. More information about the NCV7356D1R2G’s functionality, electrical specifications, and typical performance can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy-to-use functions and a usage example that may be used as a reference for the development.

Single Wire CAN Click hardware overview image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Used MCU Pins

mikroBUS™ mapper

Mode Selection Pin 0

PA7

RST

Mode Selection Pin 1

PD4

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

UART TX

PC3

UART RX

PC2

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Single Wire CAN Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Charger 27 Click front image hardware assembly

PIC18F47Q10 Curiosity Nano front image hardware assembly

Charger 27 Click complete accessories setup image hardware assembly

Board mapper by product8 hardware assembly

PIC18F57Q43 Curiosity MCU Step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

Software Support

Library Description

This library contains API for Single Wire CAN Click driver.

Key functions:

singlewirecan_set_operating_mode - The function set desired operating mode of NCV7356 Single Wire CAN Transceiver
singlewirecan_generic_write - This function write specified number of bytes
singlewirecan_generic_read - This function reads a desired number of data bytes

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 
 * \brief SingleWireCan Click example
 * 
 * # Description
 * This example demonstrate the use of Single Wire CAN Click board.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and configures the Click for the normal operation mode.
 * 
 * ## Application Task  
 * Depending on the selected mode, it reads all the received data or sends the desired message
 * every 2 seconds.
 * 
 * ## Additional Function
 * - singlewirecan_process ( ) - The general process of collecting the received data.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "singlewirecan.h"
#include "string.h"

#define PROCESS_RX_BUFFER_SIZE 500

#define TEXT_TO_SEND "MikroE\r\n"

// ------------------------------------------------------------------ VARIABLES

#define DEMO_APP_RECEIVER
// #define DEMO_APP_TRANSMITTER

static singlewirecan_t singlewirecan;
static log_t logger;

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

static void singlewirecan_process ( void )
{
    int32_t rsp_size;
    
    char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    uint8_t check_buf_cnt;
    
    rsp_size = singlewirecan_generic_read( &singlewirecan, uart_rx_buffer, PROCESS_RX_BUFFER_SIZE );

    if ( rsp_size >= strlen( TEXT_TO_SEND ) )
    {  
        log_printf( &logger, "Received data: " );
        
        for ( check_buf_cnt = 0; check_buf_cnt < rsp_size; check_buf_cnt++ )
        {
            log_printf( &logger, "%c", uart_rx_buffer[ check_buf_cnt ] );
        }
    }
    Delay_ms ( 100 );
}

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    singlewirecan_cfg_t cfg;

    /** 
     * 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.

    singlewirecan_cfg_setup( &cfg );
    SINGLEWIRECAN_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    singlewirecan_init( &singlewirecan, &cfg );
    Delay_ms ( 100 );

    singlewirecan_set_operating_mode( &singlewirecan, SINGLEWIRECAN_OPERATING_MODE_NORMAL );
    log_info( &logger, "---- Normal Operation Mode ----" );
    Delay_ms ( 100 );
}

void application_task ( void )
{
#ifdef DEMO_APP_RECEIVER
    singlewirecan_process( );
#endif    
    
#ifdef DEMO_APP_TRANSMITTER
    singlewirecan_generic_write( &singlewirecan, TEXT_TO_SEND, 8 );
    log_info( &logger, "---- Data sent ----" );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
#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;
}

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