Helpful ROS Code

Tweak params

Publish to a topic to change a parameter in your code. Probably works the same with most other singular data types. It's a good idea to make one topic per parameter, so all of them are individually changeable.

#include "std_msgs/Float32.h"

float D = 0.5; //at initialized value

void setD(const std_msgs::Float32::ConstPtr& msg){ //callback
    D = msg->data;
    ROS_INFO("D CHANGED.");
}

int main(int argc, char **argv)
{
    //node initialization stuff goes here

    ros::Subscriber Dsub = n.subscribe("wall_follow/D", 1, setD);

    ros::spin();
    
    return 0;
}

###To set ROS_IP:

$export ROS_IP='your IP address'