Custom msg

1. msg 파일 작성

~/xycar_ws/src/msg_send/msg/my_msg.msg 에 다음과 같이 작성

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

3. package.xml 수정

  ...
  <exec_depend>rospy</exec_depend>
  <exec_depend>std_msgs</exec_depend>
  # 아래 두 줄 추가
  <build_depend>message_generation</build_depend>
  <exec_depend>message_runtime</exec_depend>
  ...

2. CMakelist 수정

...

find_package(catkin REQUIRED COMPONENTS
  rospy
  std_msgs
  message_generation	# 이부분 추가
)
...

# 주석 해제후 my_msg.msg 추가
add_message_files(
  FILES
  my_msg.msg
)
...

# 주석 해제
generate_messages(
  DEPENDENCIES
  std_msgs
)
...

catkin_package(
  CATKIN_DEPENDS message_runtime	# 이부분 추가
#  INCLUDE_DIRS include
#  LIBRARIES msg_send
#  CATKIN_DEPENDS rospy std_msgs
#  DEPENDS system_lib
)

4. 확인

• $ catkin_make 후 $rosmsg show my_msg 확인

jsg@jsg-ubuntu:~/xycar_ws$ rosmsg show my_msg
[msg_send/my_msg]:
string first_name
string last_name
int32 age
int32 score
string phone_number
int32 id_number

5. 실습

• msg_sender.py

#! /usr/bin/env python

import rospy
from msg_send.msg import my_msg

rospy.init_node('msg_sender', anonymous=True)
pub = rospy.Publisher('msg_to_xycar', my_msg)

msg = my_msg()
msg.first_name = "gildon"
msg.last_name = "Hong"
msg.id_number = 20041003
msg.phone_number = "010-8990-3003"

rate = rospy.Rate(1)
while not rospy.is_shutdown():
    pub.publish(msg)
    print("sending message")
    rate.sleep()

• msg_receiver.py

#! /usr/bin/env python

import rospy
from msg_send.msg import my_msg

def callback(msg):
    print("1. Name : ", msg.last_name + msg.first_name)
    print("2. ID : ", msg.id_number)
    print("3. Phone Number : ", msg.phone_number)

rospy.init_node('msg_receiver', anonymous=True)

sub = rospy.Subscriber('msg_to_xycar', my_msg, callback)

rospy.spin()