source: rtos_arduino/trunk/arduino_lib/libraries/NcesCan/examples/send_Blink_ROS/send_Blink_ROS.ino@ 136

// demo: CAN-BUS Shield, send data
// Hardware: TWO ArduinoMega with CAN-SHIELDS
// Run this send_Blink_ROS.ino file on one of the Arduinos
// Run receive_Blink on the other
// ***ROS commands to be followe***//
// roscore
// rosrun roial_python serial_node.py /dev/ttyACM1 _baud:=57600
// rostopic pub toggle_led std_msgs/Empty -r 100
// Jaghvi: jaghvim@andrew.cmu.edu


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

//ROS
#include <ros.h>
#include <std_msgs/Empty.h>

ros::NodeHandle  nh;

const int SPI_CS_PIN = 9;
const int ledHIGH=1;
const int ledLOW=0;
unsigned char stmp[8] = {ledHIGH, 1, 2, 3, ledLOW, 5, 6, 7};

MCP_CAN CAN(SPI_CS_PIN);                                    // Set CS pin

void messageCb( const std_msgs::Empty& toggle_msg){
  //digitalWrite(13, HIGH-digitalRead(13));   // blink the led
  // send data:  id = 0x00, standrad frame, data len = 8, stmp: data buf
  CAN.sendMsgBuf(0x70,0, 8, stmp);
  delay(1000);                       // send data per 100ms
}

ros::Subscriber<std_msgs::Empty> sub("toggle_led", &messageCb );

// the cs pin of the version after v1.1 is default to D9
// v0.9b and v1.0 is default D10



void setup()
{
    Serial.begin(115200);
    nh.initNode();
    nh.subscribe(sub);

START_INIT:

    if(CAN_OK == CAN.begin(CAN_500KBPS))                   // init can bus : baudrate = 500k
    {
        Serial.println("CAN BUS Shield init ok!");
    }
    else
    {
        Serial.println("CAN BUS Shield init fail");
        Serial.println("Init CAN BUS Shield again");
        delay(100);
        goto START_INIT;
    }
}


void loop()
{   
    
    nh.spinOnce();
    delay(1);
}

/*********************************************************************************************************
  END FILE
*********************************************************************************************************/