Knowledge's profile - activity

Hello, I have created my own ros msg file and am using it in my code. When i use the following code, std_msgs::String msg;

std::stringstream ss;
ss << "hello world " << count;
msg.data = ss.str();

it says ss wasn't declared in this scope. I have used data as a member of the string i created in the msg file. Please tell me what am i missing?

I edited the complete code i used. The following error is occuring. ros::Subscriber sub = n.subscribe<robot_position::num>("Encoder_vel", 1000, chatterCallback); make[3]: * [CMakeFiles/position_node.dir/src/position_node.cpp.o] Error 1 make[3]: Leaving directory `/home/saad/jade_workspace/sandbox

Please can you give an example how should i do this?

Hi, I want to subscribe to multiple topics i am trying the following code but doesn't work. #include "ros/ros.h" #include <robot_position num.h="">

float vk; float v ; float va; float a;

void chatterCallback(const Robot_Position::Num::ConstPtr& msg1) {

    float v1 = msg1->v1;
    float vr = msg1->vr;
 va=(v1+vr)/2;}

void chatterCallback2(const Robot_Position::Num::ConstPtr& msg2) {

    float a1 = msg2->a1;
float a2 = msg2->a2;
a=(a1+a2)/2;}

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

ros::init(argc, argv, "robot_position");
ros::NodeHandle n;
ros::Subscriber sub = n.subscribe<Robot_Position::Num>("Encoder_vel", 1000, chatterCallback);

ros::NodeHandle n;
ros::Subscriber sub = n.subscribe<Robot_Position::Num>("Accelerometer", 1000, chatterCallback2);
ros::spin();

return 0;

}

Hi, I want to remove all the packages in my sandbox environment and create new ones. Is there any proper way i can do so?

I can roscd in my package, but the environment is not set, actually i am unable to know the proper syntax of export ROS_PACKAGE_PATH=/your/path/to/workspace:$ROS_PACKAGE_PATH /your/path/to/workspace what does this explain? Actually i pasted this in my .bashsrc file few days before and the environment was set permanently, but suddenly it didn't work and i deleted this line from my .bashsrc file, now i am trying to configure it again but don't remember how i managed to do that earlier.

Hi, I am having problem in configuring ROS environment. I have created a package and when i use the rospack find {package name} command it doesn't find it. I sourced the path using

export ROS_PACKAGE_PATH=/home/saad/jade_workspace/sandbox:/opt/ros/jade/share:/opt/ros/jade/stacks

and paste it in the .bashsrc file at the end, still not helpful. Rospack find command doesn't work. As i am using rosbuild please anyone help me out here. My path is not properly set. And please tell me if i am using the ros package command properly.

Edit: I can roscd in my package, but the environment is not set, actually i am unable to know the proper syntax of

export ROS_PACKAGE_PATH=/your/path/to/workspace:$ROS_PACKAGE_PATH

/your/path/to/workspace what does this explain?

Actually i pasted this in my .bashsrc file few days before and the environment was set permanently, but suddenly it didn't work and i deleted this line from my .bashsrc file, now i am trying to configure it again but don't remember how i managed to do that earlier.

i wrote

export ROS_PACKAGE_PATH=/home/saad/sandbox/jade_workspace:/opt/ros/jade/share:/opt/ros/jade/stacks

in my .bashsrc file in the last don't know if it is right.

I want to create to nodes and make them communicate on the same topic of type position,

http://wiki.ros.org/ROS/Tutorials/Und...

This tutorial helped me how to create two nodes and make them communicate on a topic. Using turtlesim i can detect the turtle position but how can i convert that position from local to global reference frame? The tutorial only shows how to make nodes and topics and use turtlesim_node as first node and turtle_teleop_key as other, turtle1/pose as the topic, but i can't get how this node can convert the coordinates that is x,y and theta and change them into global reference frame?

The ROS site guides how to create package in fuerte which i think is old version, i've installed ROS Jade and want to create a package in JADE workspace ,with this distribution, can anyone help?

thanks it says "jade" when i type "rosversion -d", this means now it is permanently installed?

Hey, i wanted to ask when i follow the installation steps given on the site, i execute the commands" Ubuntu install of ROS Jade" and when i reach the end do i need to verify that ros is installed? When i close the terminal ROS vanishes? How can i know that whenever i open UBUNTU Ros will be installed?

Because when i go through the steps and verify by typing "ros versionros" it says"unversioned" and when i close and open terminal again it says"command ros not found" i know it maybe a silly question but i am a newbie:)

Having trouble when i check if ROS is installed properly i typed this "source /opt/ros/<distro>/setup.bash" it says "unversioned" what does it mean?

when i type in the command to check if ROS is installed "source /opt/ros/<distro>/setup.bash"

i want to create two nodes on ROS, and want them to communicate and analyze the robot's local and global reference frames. To be precise i want to examine the position of the robot in x, y and theta coordinates, then send this result to another node which will convert it to global reference frame and then send it to another node. please help me with this.

to check if ros is installed or not i've typed "source /opt/ros/<distro>/setup.bash" it says "unversioned" what does it mean?