The following two functions should be launched in two separate python threads.
They show how easy ROS enables to create a pub/sub relationship for transferring messages between nodes.
sub.py
*import rospy*
from std_msgs.msg import String
def talker():
pub = rospy.Publisher('chatter', String, queue_size=10)
rospy.init_node('talker', anonymous=True)
rate = rospy.Rate(10) # 10hz
while not rospy.is_shutdown():
hello_str = "hello world %s" % rospy.get_time()
rospy.loginfo(hello_str)
pub.publish(hello_str)
rate.sleep()
talker()
*pub.py*
import rospy from std_msgs.msg import String def callback(data): rospy.loginfo(rospy.get_caller_id() + 'I heard %s', data.data) def listener(): rospy.init_node('listener', anonymous=True) rospy.Subscriber('chatter', String, callback) rospy.spin() listener()