Here is the same thing I tried with turtlesim and it works fine.

#include "ros/ros.h"
#include "geometry_msgs/Twist.h"
#include "turtlesim/Pose.h"
#include <sstream>

using namespace std;

ros::Publisher velocity_publisher;
ros::Subscriber pose_sub;
turtlesim::Pose turtlesim_pose;

void poseCallback(const turtlesim::Pose::ConstPtr & pose_message);
void moveUp(double distance_tolerance);

int main(int argc, char **argv)
{
    ros::init(argc, argv, "sphero_move");
    ros::NodeHandle n;

    velocity_publisher = n.advertise<geometry_msgs::twist>("/turtle1/cmd_vel", 1000);
    pose_sub = n.subscribe("/turtle1/pose", 10, poseCallback);  
    ros::Rate loop_rate(0.5);

    moveUp(0.5);
    loop_rate.sleep();

    ros::spin();

    return 0;

}

void poseCallback(const turtlesim::Pose::ConstPtr & pose_message)
{
    turtlesim_pose.x=pose_message->x;
}

void moveUp(double distance_tolerance)
{
    geometry_msgs::Twist vel_msg;
    ros::Rate loop_rate(10);

    do{
        vel_msg.linear.x = 1;
        vel_msg.linear.y = 0;
        vel_msg.linear.z = 0;

        velocity_publisher.publish(vel_msg);

        ros::spinOnce();
        loop_rate.sleep();

        }while((turtlesim_pose.x-8)<distance_tolerance); }="" <="" pre="">

Here is the same thing I tried with turtlesim and it works fine.

#include "ros/ros.h"
#include "geometry_msgs/Twist.h"
#include "turtlesim/Pose.h"
#include <sstream>

using namespace std;

ros::Publisher velocity_publisher;
ros::Subscriber pose_sub;
turtlesim::Pose turtlesim_pose;

void poseCallback(const turtlesim::Pose::ConstPtr & pose_message);
void moveUp(double distance_tolerance);

int main(int argc, char **argv)
{
    ros::init(argc, argv, "sphero_move");
    ros::NodeHandle n;

    velocity_publisher = n.advertise<geometry_msgs::twist>("/turtle1/cmd_vel", 1000);
    pose_sub = n.subscribe("/turtle1/pose", 10, poseCallback);  
    ros::Rate loop_rate(0.5);

    moveUp(0.5);
    loop_rate.sleep();

    ros::spin();

    return 0;

}

void poseCallback(const turtlesim::Pose::ConstPtr & pose_message)
{
    turtlesim_pose.x=pose_message->x;
}

void moveUp(double distance_tolerance)
{
    geometry_msgs::Twist vel_msg;
    ros::Rate loop_rate(10);

    do{
        vel_msg.linear.x = 1;
        vel_msg.linear.y = 0;
        vel_msg.linear.z = 0;

        velocity_publisher.publish(vel_msg);

        ros::spinOnce();
        loop_rate.sleep();

        }while((turtlesim_pose.x-8)<distance_tolerance); }="" <="" pre="">

Here is the same thing I tried with turtlesim and it works fine.

#include "ros/ros.h"
#include "geometry_msgs/Twist.h"
#include "turtlesim/Pose.h"
#include <sstream>
include "ros/ros.h"
 
include "geometry_msgs/Twist.h"
 
include "turtlesim/Pose.h"
 
include <sstream>
 
using namespace std;

ros::Publisher velocity_publisher;
ros::Subscriber pose_sub;
turtlesim::Pose turtlesim_pose;

void poseCallback(const turtlesim::Pose::ConstPtr & pose_message);
void moveUp(double distance_tolerance);

int main(int argc, char **argv)
{
    ros::init(argc, argv, "sphero_move");
    ros::NodeHandle n;

 
velocity_publisher = n.advertise<geometry_msgs::twist>("/turtle1/cmd_vel", n.advertise<geometry_msgs::Twist>("/turtle1/cmd_vel", 1000);
 pose_sub = n.subscribe("/turtle1/pose", 10, poseCallback);  
 ros::Rate loop_rate(0.5);

 moveUp(0.5);
 loop_rate.sleep();

 ros::spin();

 return 0;

}

 
}
 
void poseCallback(const turtlesim::Pose::ConstPtr & pose_message)
{
    turtlesim_pose.x=pose_message->x;
}

}
 
void moveUp(double distance_tolerance)
{
    geometry_msgs::Twist vel_msg;
    ros::Rate loop_rate(10);

    loop_rate(10);
 
do{
     vel_msg.linear.x = 1;
     vel_msg.linear.y = 0;
     vel_msg.linear.z = 0;

     velocity_publisher.publish(vel_msg);

     ros::spinOnce();
     loop_rate.sleep();

        }while((turtlesim_pose.x-8)<distance_tolerance); }="" <="" pre="">
}while((turtlesim_pose.x-8)<distance_tolerance);
 
}
 

Here is the same thing I tried with turtlesim and it works fine.

 
include "ros/ros.h"
 
include "geometry_msgs/Twist.h"
 
include "turtlesim/Pose.h"
 
include <sstream>
 
using namespace std;
std;  
ros::Publisher velocity_publisher;
ros::Subscriber pose_sub;
turtlesim::Pose turtlesim_pose;
turtlesim_pose;  
void poseCallback(const turtlesim::Pose::ConstPtr & pose_message);
void moveUp(double distance_tolerance);
distance_tolerance);  
int main(int argc, char **argv)
{
 ros::init(argc, argv, "sphero_move");
 ros::NodeHandle n;
n; 
 
velocity_publisher = n.advertise<geometry_msgs::Twist>("/turtle1/cmd_vel", n.advertise<geometry_msgs::twist>("/turtle1/cmd_vel", 1000);
pose_sub = n.subscribe("/turtle1/pose", 10, poseCallback);  

ros::Rate loop_rate(0.5);
loop_rate(0.5);  
moveUp(0.5);
loop_rate.sleep();
loop_rate.sleep(); ros::spin();
 
ros::spin();
 
return 0;
0;
 
}
 
void poseCallback(const turtlesim::Pose::ConstPtr & pose_message)
{
 turtlesim_pose.x=pose_message->x;
}
 
void moveUp(double distance_tolerance)
{
 geometry_msgs::Twist vel_msg;
 ros::Rate loop_rate(10);
 
do{
 vel_msg.linear.x = 1;
 vel_msg.linear.y = 0;
 vel_msg.linear.z = 0;

    velocity_publisher.publish(vel_msg);

    ros::spinOnce();
    loop_rate.sleep();

    }while((turtlesim_pose.x-8)<distance_tolerance);
0;
 
velocity_publisher.publish(vel_msg);
 
ros::spinOnce();
loop_rate.sleep();
 
}while((turtlesim_pose.x-8)<distance_tolerance);< p="">

}
 

Here is the same thing I tried with turtlesim Was making a mistake, and it works fine.finally found it.

 
include "ros/ros.h"
 
include "geometry_msgs/Twist.h"
 
include "turtlesim/Pose.h"
 
include <sstream>void poseCallback(const std_msgs::Float32::ConstPtr & pose_message){ ball_pose.data = pose_message->data;}

using namespace std;thanks

Was making a mistake, and finally found it.

void poseCallback(const std_msgs::Float32::ConstPtr & pose_message){ ball_pose.data = pose_message->data;}

thanks