Processing Delay Subscriber

1_2_처리지연_receiver.ipynb
Running the cell code

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import rospy
from std_msgs.msg import Int32

Import rospy modules
Import Int32 from std_msgs.msg module

rospy.init_node('Receiver')

Create Receiver Node

pre_num = 0
cur_num = 0

Set variable pre_num to 0
Set variable cur_num to 0

def callback(msg):
    global pre_num
    global cur_num

    print("Callback is being processed")
    cur_num = msg.data
    rospy.sleep(3)

    if (cur_num - pre_num) != 1:
        print_str = "Data: {0:>6}    Missing: {1:6} ~ {2:>6} (  cnt: {3}  )\n"\
        .format(msg.data,pre_num +1, cur_num -1, cur_num - pre_num -1)
    else:
        print_str = "Data: " + str(msgs.data) + "\n"

    print(print_str)
    pre_num = cur_num

Create callback(msg) function
Declare pre_num and cur_num as global variables
Designate cur_num as message data
3 second time delay
cur_num - if pre_num is not 1,
- Output in order of message data, pre_num + 1, cur_num -1, cur_num - pre_num -1
- Data: (current data) Missing: (minimum value of missing data ~ maximum value of missing data) (cnt: (number of missing data))
Other cases
- Message data output
Specify pre_num as cur_num

sub = rospy.Subscriber('increase_num', Int32, callback, queue_size=1)
rospy.spin()

Create increase_num Topic Subscriber