CAN Introduction

This post will consolidate the information on CAN as much as possible , to be used as quick reference for new Bees.

Good Introduction to CAN is  available in the following URL.

Please note that the link works with IE or FireFox and not with chrome.

http://microcontroller.com/learn-embedded/CAN1_sie/CAN1_files/frame.htm


Good Resources on CAN FD :  CAN with Flexible Data-Rate
http://www.can-cia.org/fileadmin/cia/files/icc/13/hartwich.pdf

Arduino Uno R3 and MCP2515 CAN breadboard proto type

I have created a  simple prototype of CAN network using  the following setup
1. Arduino Uno R3 x1
2. CAN bus shield  from seeedstudio.com  x1
3. CAN Shield circuit wired on breadboard using MCP2515 & MCP2551   x1


One node is configured to send the CAN message over CAN id 0x01. the first byte of CAN frame is incremented by one to use it is a running counter. The other node is configured to receive the CAN message and print it on serial console.

Result observed on Serial Monitor

Arduino sketch attached for your refernce

// demo: CAN-BUS Shield, receive data with check mode
// send data coming to fast, such as less than 10ms, you can use this way
// loovee, 2014-6-13


#include <SPI.h>
#include "mcp_can.h"


// the cs pin of the version after v1.1 is default to D9
// v0.9b and v1.0 is default D10
const int SPI_CS_PIN = 10;
const int SPI_CS_PIN_CAN_BREADBOARD = 9;

MCP_CAN CAN(SPI_CS_PIN);                                    // Set CS pin
MCP_CAN CAN2(SPI_CS_PIN_CAN_BREADBOARD);                   

void setup()
{
    Serial.begin(115200);

START_INIT:

    if(CAN_OK == CAN.begin(CAN_500KBPS))                   // init can bus : baudrate = 500k
    {
        Serial.println("CAN-1 BUS Shield init ok!");
    }
    else
    {
        Serial.println("CAN-1 BUS Shield init fail");
        Serial.println("Init-1 CAN BUS Shield again");
        delay(1000);
        goto START_INIT;
    }
    if(CAN_OK == CAN2.begin(CAN_500KBPS))                   // init can bus : baudrate = 500k
    {
        Serial.println("CAN-2 BUS Shield init ok!");
    }
    else
    {
        Serial.println("CAN-2 BUS Shield init fail");
        Serial.println("Init-2 CAN2 BUS Shield again");
        delay(1000);
        goto START_INIT;
    }
}