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2018-08-28 14:44:57 -0500 asked a question gyro calibration not working

gyro calibration not working Hello, I followed instructions from here. I place my turtlebot infront of a wall and run

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2018-07-15 10:22:21 -0500 commented answer unit_cylinder not a model in turtlebot3_world

Partial answer to my question. I found the model.sdf file but, I am still looking for answers on how to change those val

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2018-07-14 21:46:46 -0500 answered a question unit_cylinder not a model in turtlebot3_world

It's here: catkin_ws/src/turtlebot3_simulations/turtlebot3_gazebo/models/turtlebot3_world$ gedit model.sdf How can I cha

2018-07-14 20:42:17 -0500 asked a question unit_cylinder not a model in turtlebot3_world

unit_cylinder not a model in turtlebot3_world Hi guys, I am launching a gazebo world using: export TURTLEBOT3_M

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2017-04-30 02:58:47 -0500 marked best answer unable to extract images from bag file

http://wiki.ros.org/rosbag/Tutorials/... I am following this tutorial. after I did roslaunch export.launch,

"" [rosbag-2] process has finished cleanly
log file: /home/krish/.ros/log/2e6402e2-2086-11e5-8d8c-0026c72b65a2/rosbag-2*.log"""

this is the message i got I did ctrl+c moved this file into test directory. but I can;t see any images here

Also, i actually want to extract stereo images. when I do rosbag info, I get:

types:       sensor_msgs/Image [060021388200f6f0f447d0fcd9c64743]
topics:      /rrc_camera/left/image_raw    171 msgs    : sensor_msgs/Image
             /rrc_camera/right/image_raw   171 msgs    : sensor_msgs/Image
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2015-07-17 04:24:29 -0500 answered a question publisher and subscriber in single node

hello, I have done it as per the solutions give here.

I am subscribing to a sensor_msgs::Image, and I want to publish my_package/RectifiedImage.msg over a topic "mycustomtopic".

When I do "rostopic list", it is showing /mycustomtopic

When I do "rostopic echo mycustomtopic", it is showing "the rosdep view is empty: call 'sudo rosdep init' and 'rosdep update' ERROR: Cannot load message class for [stereo_msgs/RectifiedImage]. Are your messages built?"

this is what I was doing:

void callback(const ..){

..

my_msg_pub_.publish(myimage);

..

return;

}

and

int main(int argc , char** argv){

subscribe to sensor_msgs::Image

callback

my_msg_pub_ = nh.advertise<stereo_msgs::rectifiedimage>("mycustomtopic", 1);

ros::spin();

return 0;

}

where could be my mistake?

2015-07-16 15:35:32 -0500 asked a question ERROR: Cannot load message class for [stereo_msgs/RectifiedImage]. Are your messages built?

http://answers.ros.org/question/18707... http://answers.ros.org/question/62430... https://github.com/epsilonorion/rosco... http://answers.ros.org/question/57103...

these answers did not help me.

in my workspace, I have my custom message stereo_msgs/RectifiedImage.msg I want to publish that.

when I do rostopic list, I can see "/mycustomtopic"

but when I do rostopic echo, "ERROR: Cannot load message class for [stereo_msgs/RectifiedImage]. Are your messages built?"

my_msg_pub_ = nh.advertise<stereo_msgs::rectifiedimage>("mycustomtopic", 1);

this is in my main function

and in my callback function (i am subscring to other message type),

my_msg_pub_.publish(myimage);

pls help me out

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2015-07-13 13:33:58 -0500 commented answer subscribing to custom message type

no, they are not connected. I did "rostopic list" to find out that "mycustomtopic" is being published

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2015-07-13 08:58:31 -0500 commented answer subscribing to custom message type

not exactly. please see my edited question

2015-07-13 07:25:34 -0500 commented answer subscribing to custom message type

NO! I included it now, and it worked!

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2015-07-13 06:11:43 -0500 commented answer subscribing to custom message type

yes, it is included

2015-07-13 05:35:41 -0500 commented answer subscribing to custom message type

done! sorry for the inconvinience

2015-07-13 04:07:02 -0500 commented answer subscribing to custom message type

Linking CXX executable /home/krish/architecture_ws/devel/lib/compute_disparity/hsvgmmN CMakeFiles/hsvgmmN.dir/src/hsvgmmN.cpp.o: In function `ros::Subscriber ros::NodeHandle::subscribe<swahana_v2::rectified_image_<std::allocator<void> > >(std::basic_string<char, std::char_traits<char="">, std::allocato

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2015-07-13 02:45:41 -0500 commented answer subscribing to custom message type

void chatterCallback(const swahana_v2::rectified_image::ConstPtr &msg){ std::cout << "checker" << std::endl; }

2015-07-12 12:27:21 -0500 commented answer subscribing to custom message type

that also did not work! :(

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2015-07-12 04:42:17 -0500 commented answer subscribing to custom message type

void chatterCallback(const rectified_imageConstPtr &msg) is my callback function.. and I got the following error message:

/home/krish/architecture_ws/src/compute_disparity/src/hsvgmmN.cpp:116:28: error: ‘rectified_imageConstPtr’ does not name a type

I have the rectified_image.msg as my custom

2015-07-10 14:16:40 -0500 asked a question subscribing to custom message type

I have created a custom message type. I am able to successfully publish it with the topic name "topic".

int8 seq_id
std_msgs/Header timestamp
int8 frame_id
float64 myheight
float64 mywidth
int16 step_value
sensor_msgs/Image my_left
sensor_msgs/Image my_right

is my custom message.

I created a new package. I want to subscribe to the node publishing "topic".

int main(int argc, char **argv)
{
    ros::init(argc, argv, "listener");

    ros::NodeHandle n;

        std::cout << "hello disparity" << std::endl;

        ros::Subscriber sub = n.subscribe("mycustomtopic",1000,chatterCallback);

        std::cout << "after subscription disparity" << std::endl;

        ros::spin();

        std::cout << "after spin disparity" << std::endl;

        return 0;
}

is my main function.

void chatterCallback(const swahana_v2::rectified_imageConstPtr &msg){
    std::cout << "checker " << std::endl;
    return;
}

is my callback function written in the same node.

and the output is

hello disparity

after subscription disparity

^Cafter spin disparity

following is my CMakeLists.txt

cmake_minimum_required(VERSION 2.8.3)

project(compute_disparity)

set(CMAKE_BUILD_TYPE Release)

find_package(catkin REQUIRED COMPONENTS
  rectifier

  roscpp

  rospy

  std_msgs

  swahana_v2

  sensor_msgs
)

catkin_package()

include_directories( ${catkin_INCLUDE_DIRS})

include_directories(include ${catkin_INCLUDE_DIRS})

add_executable(hsvgmmN src/hsvgmmN.cpp)

target_link_libraries(hsvgmmN ${catkin_LIBRARIES})

add_dependencies(hsvgmmN compute_disparity_generate_messages_cpp)

target_link_libraries(hsvgmmN ${catkin_LIBRARIES})

target_link_libraries (hsvgmmN elas viso ${PCL_LIBRARIES} ${OpenCV_LIBS} )

find_package(message_generation)

catkin_package(CATKIN_DEPENDS message_runtime)

add_message_files(

  DIRECTORY ../swahana_v2/msg

  FILES rectified_image.msg
)

find_package(catkin REQUIRED COMPONENTS swahana_v2)

add_dependencies(hsvgmmN swahana_v2_generate_messages_cpp)

but, "checker" is not getting printed. This means, there is still some problem with the callback function. please help!

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2015-07-09 03:37:17 -0500 asked a question convert sensor_msgs::ImagePtr to sensor_msgs::Image

I would like to do that conversion http://answers.ros.org/question/9998/... I looked at this answer, but I want to do the opposite of this.

sensor_msgs::ImagePtr msg1; msg1 = cv_bridge::CvImage(std_msgs::Header(), "bgr8", imageMat1).toImageMsg(); I have written this in my code. Now, I am confused how to convert this msg1 to sensor_msgs::Image myimage;

might be a simple question, but couldn't find the solution anywhere

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2015-07-07 07:00:50 -0500 marked best answer writing a custom message and using it in a different package

first of all, I have gone through these links, so it is not a repeat question:

and i tried all of these solutions, but they did not help me.

The question is..

I have created a msg folder in package 'A'. wrote hello.msg in that 'msg' folder. I followed this tutorial: http://wiki.ros.org/ROS/Tutorials/Cre... and catkin_make worked fine here.

I now created a new package 'B' , has a node 'helpme.cpp' and in that I have written #include "A/hello.h" and I defined

A::hello left,right;
left.myheight = image.rows;
left.mywidth = image.cols;

.....in the callback function and when I do catkin_make, it says..

/home/krish/architecture_ws/src/rectifier/src/camera_timestamp_node.cpp:276:6: error: ‘const ImageConstPtr’ has no member named ‘mywidth’
/home/krish/architecture_ws/src/rectifier/src/camera_timestamp_node.cpp:277:6: error: ‘const ImageConstPtr’ has no member named ‘myheight’

pls tell me what changes should I make in CMakeLists.txt and package.xml in the packages A and B.

2015-07-07 06:49:01 -0500 answered a question writing a custom message and using it in a different package

I got this problem because of my programming mistake. I have given the same variable name to both ImageConstPtr and my own message type. the problem is solved now thanks gvdhoorn and cyborg-x1