search

ros / ros_tutorials

Code used in tutorials found on ROS wiki
http://wiki.ros.org/ros_tutorials
805 stars 540 forks source link

keyboard cannot work when running "rosrun turtlesim turtle_teleop_key" #40

Closed guchaojie closed 7 years ago

guchaojie commented 7 years ago

My enviroment is NAME="Ubuntu" VERSION="16.04.2 LTS (Xenial Xerus)"

kernel is 4.4.0-75-generic running step is:

  1. roscore
  2. rosrun rosrun turtlesim turtlesim_node
  3. rosrun turtlesim turtle_teleop_key The result is : keyboard cannot work to drive turtlebot move in simulator the root cause is 88 if(read(kfd, &c, 1) < 0) 89 { 91 perror("read():"); 92 exit(-1); 93 } line 88: read function is being hung there, cannot running down to publish turtle1/cmd_vel topic.
dirk-thomas commented 7 years ago

I am not sure I understand your problem. The line containing the read is waiting for keyboard events. It is supposed to block until you press any key, then the loop processes the event and waits for the next input. Please describe your problem with more details: what are the exact steps you do, what is the exact output, what are expecting, etc?

guchaojie commented 7 years ago

I found the problem reason is that I put the turtlesim simulator in front of screen to enter keyboard, the right way is to put terminal in front of screen as active to wait for keyboard event