Cayero's profile - activity

Hi I'm new in ROS, and I have a problem with turtlebot_gazebo.

Here I got the code which I would like to use to move the robot.

import rospy
from geometry_msgs.msg import Twist

cmd_vel_pub = rospy.Publisher('cmd_vel', Twist, queue_size=1)
rospy.init_node('red_light_green_light')

red_light_twist = Twist()
green_light_twist = Twist()
green_light_twist.linear.x =5

driving_forward = False
light_change_time = rospy.Time.now()
rate = rospy.Rate(10)

while not rospy.is_shutdown():
             if driving_forward:
                        cmd_vel_pub.publish(green_light_twist)
             else:
                        cmd_vel_pub.publish(red_light_twist)
             if light_change_time > rospy.Time.now():
                        driving_forward = not driving_forward
                        light_change_time = rospy.Time.now() + rospy.Duration(3)
             rate.sleep()

This is the code from 'Programming robots with ROS' book.

Then in new terminal I use that command

./red_light_green_light.py cmd_vel:=cmd_vel_mux/input/teleop

and again in new terminal I'm running the code

rosrun wanderbot red_light_green_light.py

after that in the previous terminal i got this

shutdown request: new node registered with the same name
Traceback (most recent call last):
 File "./red_light_green_light.py", line 25, in <module>
 rate.sleep()
     File "/opt/ros/indigo/lib/python2.7/dist-packages/rospy/timer.py", line 99, in
    sleep
        sleep(self._remaining(curr_time))
 File "/opt/ros/indigo/lib/python2.7/dist-packages/rospy/timer.py", line 157, in 
sleep
        raise rospy.exceptions.ROSInterruptException("ROS shutdown request")
rospy.exceptions.ROSInterruptException: ROS shutdown request

The turtle in gazebo is not moving. Could someone give some advice? I would be really grateful.

Hi I would like to add SDL2 library with headers to cmake. How can do that?? I'm new in ROS. I've tried something like this

include_directories(
include ${SDL2_INCLUDE_DIRS}
include ${catkin_INCLUDE_DIRS}
)

Could anyone help me? I would be very grateful

Hi guys, I have a problem with my cmake compiler.

I have Ubuntu 14.04 LTS and ROS-Indigo. I had Cmake version 2.8.13 and gcc version 4.8. I wanted to update cmake and gcc compiler. Now I have cmake version 3.81 and gcc version 6.2.0. After that update i cannot build my packages. I'm getting erorr like that:

The CXX compiler identification is unknown
CMake Error in :
  No CMAKE_CXX_COMPILER could be found.

  Tell CMake where to find the compiler by setting either the environment
  variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
  to the compiler, or to the compiler name if it is in the PATH.

I think i have to change the path of the compiler but i do not know how. Could you help me? Should i remove ROS and install again?

Thank you for your answer, I'll on that. I found some helpful code. But client_node cannot connect to the server. https://github.com/abhinavjain241/com...

I need to implement something that could send data from a not-ROS-running System(A) to a ROS-running System(Z) and later sending data from Z back to A using a TCP connection (using socket). I was looking for something on that page http://wiki.ros.org/ROS/TCPROS but it is not clear for me. Are there any tutorials/codes to launch a server on a ROS-running System and listening for clients? Are there any packages that allow to implement TCP communication?

@gvdhoorn using rosserial, should I use arduino platform? In this way it would look like this: Arduino connected through wire with PC then Arduino connected with WLAN module through WiFi. Is that possible?

But how to set ROS_MASTER_URI on my robot (pololu 3pi)?? It has only Atmega328 controller.

Hi, I'm new with ROS. I have a robot (Pololu 3pi) with WLAN module. I would like to communicate with that robot wirelessly through TCP or WiFi (to remote control). I was looking some information on this site http://wiki.ros.org/ROS/TCPROS but i couldn't find anything helpful. I would be very grateful for any response.

Hi, I've got a robot Pololu 3pi with Atmega328 microcontroller. The robot has also built-in a WLAN module which let me connect my computer with this robot. I would like to control the robot using my keyboard.

There is a question: is there possibility to remote control this robot with the aid of ROS? I mean if it is possible to program this robot using ROS? Do you know any tutorials, or have any information that could be useful? I would be very grateful.

No I didn't. Just copied that xml code to my file

I just created urdf file and then copied the code