[ROS] Topic 가공 후 재전송

1. my_msg 형식

string first_name
string last_name
int32 age
int32 score
string phone_number
int32 id_number

2. 파일 작성

remote_teacher.py

#!/usr/bin/env python

import rospy
import time
from std_msgs.msg import String
from msg_send.msg import my_msg

name = "teacher"
pub_topic = "msg_from_teacher"
sub_topic = "msg_to_teacher"

def callback(msg):
    student_name =  msg.last_name + ' ' + msg.first_name
    curr_time = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime())
    result_str = "Good morning, "+student_name+' '+curr_time

    pub.publish(result_str)

rospy.init_node(name)
sub = rospy.Subscriber(sub_topic, my_msg, callback)
pub = rospy.Publisher(pub_topic, String, queue_size=1)

rospy.spin()

remote_student.py

#!/usr/bin/env python

import rospy
from std_msgs.msg import String
from msg_send.msg import my_msg

name = "student"
pub_topic = "msg_to_teacher"
sub_topic = "msg_from_teacher"

def callback(msg):
    print(msg.data)

rospy.init_node(name)
pub = rospy.Publisher(pub_topic, my_msg, queue_size=1)
sub = rospy.Subscriber(sub_topic, String, callback)

rate = rospy.Rate(1)

student_data = my_msg()
student_data.first_name = "Gil-Dong"
student_data.last_name = "Hong"
student_data.age = 20
student_data.score = 100
student_data.id_number = 12345678
student_data.phone_number = "010-1234-5678"

while not rospy.is_shutdown():
    pub.publish(student_data)
    print("sending message...")
    rate.sleep()

sr_remote.launch

<launch>
    <node name="teacher" pkg="msg_send" type="remote_teacher.py" output="screen" />
    <node name="student" pkg="msg_send" type="remote_student.py" output="screen" />
</launch>

3. chmod

4. 실행

$ roslaunch msg_send sr_remote.launch

$ rostopic echo msg_to_teacher
$ rostopic echo msg_from_teacher

$ rqt_graph