mohamed ahmed's profile - activity

You can use rosnode_ping_all() or rosnode_ping() import rosnode alive_nodes, unpinged_nodes = rosnode.rosnod

i made a simple publisher which publish a Int16. the problem is in the subscriber i try to receive the int16 and add a constant number to it for example 2 the publisher code:

#!/usr/bin/env python
# license removed for brevity
import rospy
from std_msgs.msg import Int16
import random
def ty():
    pub = rospy.Publisher('to', Int16, queue_size=10)
    rospy.init_node('talker1')
    r = rospy.Rate(1) # 1hz
    while not rospy.is_shutdown():

        value=random.randint(0, 100)
        print(value)
        pub.publish(value)
        r.sleep()
if __name__ == '__main__':
    try:
        ty()
    except rospy.ROSInterruptException:
        pass

the subscriber code:

#!/usr/bin/env python
# license removed for brevity
import rospy
from std_msgs.msg import Int16

def cb(x):
    rospy.loginfo(x+2)
def listener():


    # In ROS, nodes are uniquely named. If two nodes with the same
    # node are launched, the previous one is kicked off. The
    # anonymous=True flag means that rospy will choose a unique
    # name for our 'listener' node so that multiple listeners can
    # run simultaneously.
    rospy.init_node('listener', anonymous=True)

    rospy.Subscriber("to", Int16, cb)
    rospy.spin()

if __name__ == '__main__':
    listener()

i got this error :

TypeError: unsupported operand type(s) for +: 'Int16' and 'int'

how can i solve this problem

This answer might be helpful https://answers.ros.org/question/222306/transform-a-pose-to-another-frame-with-tf2-in-pytho

To check if the script(python code) is working Run this python script. And in another terminal run rostopic echo /cmd_ve

To know the amount of unkown by using this method. getUnknownLeafCenters for example: ourmap.getUnknownLeafCenters(l, m

To know the amount of unkown by using this method. getUnknownLeafCenters

I didn't follow the steps by myself, but according to the instruction after building the workspace you should have a oro

to install orocos_kdl sudo apt install liborocos-kdl-dev is ros_mara_ws your custom workspace or you are following a tu

You can iterate over the leafs of your map and set the bounding box(which has values around your robot) for (octomap::O

You can iterate over the leafs of your map and set the bounding box(which has values around your robot) for (octomap::O

Can you try to edit the launch file add remap to it and check if it is working <remap from="/move_base_simple/goal" t

Clone this repo into your workspace/src directory and it should work

I'm not sure if it is a good practice to edit read only files, but you can do so using the following command sudo gedit

You can remap the topics in your launch file

Check this it may answer your question

After processing the data in the call back you can invoke pub.publish(YOUR_DATA), in the callback also.

You can try execute each command seprately because with && if one command fail the others will not be executed

You can use ros::topic::waitForMessage

What is the size of octomap? I'm working with octomap, I call the /octomap_binary service, and convert it to octree. As

You can use octomap_msgs/conversions.h just include this file and then you can use all the fuctions for example: octoma

Check this it may help

How to build global map using octomap? Hello everyone, I build a simple launch file where I launch the octomap_server a

This may help, it contain functions to read and write octomaps

Have a look at conversion.h which contain methods to read and write octomaps

To launch octomap_server add the following to your launch file: <node pkg="octomap_server" type="octomap_server_no

hello, when i try to use catkin_make for my workspace, i got this error

CMake Error at /opt/ros/kinetic/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
  Could not find a package configuration file provided by "gazebo_ros" with
  any of the following names:

    gazebo_rosConfig.cmake
    gazebo_ros-config.cmake

  Add the installation prefix of "gazebo_ros" to CMAKE_PREFIX_PATH or set
  "gazebo_ros_DIR" to a directory containing one of the above files.  If
  "gazebo_ros" provides a separate development package or SDK, be sure it has
  been installed.
Call Stack (most recent call first):
  RoboND-Kinematics-Project/gazebo_grasp_plugin/CMakeLists.txt:9 (find_package)


-- Configuring incomplete, errors occurred!
See also "/home/mohamed/Documents/workspace/build/CMakeFiles/CMakeOutput.log".
See also "/home/mohamed/Documents/workspace/build/CMakeFiles/CMakeError.log".
Makefile:1914: recipe for target 'cmake_check_build_system' failed
make: *** [cmake_check_build_system] Error 1
Invoking "make cmake_check_build_system" failed

my workspace contain only this package in the src: https://github.com/udacity/RoboND-Kin...

i removed my gazebo and installed a new version gazebo9, i thought this what cause the error so i removed it and installed gazebo7 again.

when i try to use catkin_make with a workspace which doesn't contain any thing related to gazebo it works fine. i am using Ubuntu 16, gazebo 7.14.0, kinetic-kame. Thanks in advance