自作７セグLEDドライバをRaspberry piで動かすROSのシンプルなSubscriberをC++でサクッと書いてみた

/*
 * Copyright (C) 2008, Morgan Quigley and Willow Garage, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the names of Stanford University or Willow Garage, Inc. nor the names of its
 *     contributors may be used to endorse or promote products derived from
 *     this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "ros/ros.h"
#include "std_msgs/String.h"

/** Added Code starts from here. */
#include <fstream>
#include <iostream>
#include <string>

void chatterCallback(const std_msgs::String::ConstPtr& msg)
{
//  ROS_INFO("I heard: [%s]", msg->data.c_str());
    std::ofstream ofs("/dev/odssledc"); 
    ofs << msg->data.c_str() << std::endl;
}
/** Added code ends here. **/

int main(int argc, char **argv)
{

  ros::init(argc, argv, "listener");
  ros::NodeHandle n;
  ros::Subscriber sub = n.subscribe("chatter", 1000, chatterCallback);
  ros::spin();

    return 0;
}

#include <fstream>
#include <iostream>
#include <string>

void chatterCallback(const std_msgs::String::ConstPtr& msg)
{
//  ROS_INFO("I heard: [%s]", msg->data.c_str());
    std::ofstream ofs("/dev/odssledc"); 
    ofs << msg->data.c_str() << std::endl;
}

#!/usr/bin/env python
import rospy
from std_msgs.msg import UInt16

def write_mydevice(num):
    mydevice = "/dev/odssledc"
    try:
        with open(mydevice,"w") as f:
            f.write(str(num))
    except IOError:
        rospy.logger("error: write to " + mydevice)

def receive_num(data):
    write_mydevice(data.data)

if __name__ == '__main__':
    rospy.init_node('odssled')
    rospy.Subscriber("odssled",UInt16, receive_num)
    rospy.spin()

$ rostopic pub -1 '/odssled' std_msgs/UInt16 3