mr19b020's profile - activity

Hello, I am trying to make a simple program which sends a cmd_vel message. My program is looking like this right now. I work on an virtual machine with Ubuntu (ROS noetic) if that matters.

#include "ros/ros.h"
#include "geometry_msgs/Twist.h"
#include "std_msgs/String.h"

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

  ros::init(argc, argv,"talker");
  ros::NodeHandle nh;

  ros::Publisher chatter;
  chatter = nh.advertise<geometry_msgs::Twist>("/rosbot/cmd_vel", 100);
  ros::Rate loop_rate(10);
    geometry_msgs::Twist msg;
    msg.linear.x = 1;
    msg.linear.y = 0;
    msg.linear.z = 0;
    msg.angular.x = 0;
    msg.angular.y = 0;
    msg.angular.z = 0;
    ROS_INFO_STREAM("Sent message is: "<<msg.linear.x);
    chatter.publish(msg);
    ros::spin();

  return 0;
}

I can enter this in the command line and the robot moves without a problem:

rostopic pub /rosbot/cmd_vel geometry_msgs/Twist "linear:
  x: 0.0
  y: 0.0
  z: 0.0
angular:
  x: 0.0
  y: 0.0
  z: 0.0

Where is the problem in my code?

Hi, thanks for the answer and the good explanation. The program now works even with the "/" in the advertise statement.

Making a simple program which uses cmd_vel Hello, I am trying to make a simple program which sends a cmd_vel message. My