Connect USB Joystick to Turtlesim

teleop_turtle_joy.cpp

/*
 * teleop_turtle_joy.cpp
 *
 *  Created on: Dec 25, 2014
 *      Author: tedy
 */

#include <ros/ros.h>
#include <turtlesim/Velocity.h>
#include <sensor_msgs/Joy.h>

class TeleopTurtle
{
public:
	TeleopTurtle();
private:
	void joyCallback(const sensor_msgs::Joy::ConstPtr& joy);
	ros::NodeHandle nh_;

	int linear_, angular_;
	double l_scale_, a_scale_;
	ros::Publisher vel_pub_;
	ros::Subscriber joy_sub_;
};

TeleopTurtle::TeleopTurtle():
  linear_(1),
  angular_(2)
{
	nh_.param("axis_linear", linear_, linear_);
	nh_.param("axis_angular", angular_, angular_);
	nh_.param("scale_angular", a_scale_, a_scale_);
	nh_.param("scale_linear", l_scale_, l_scale_);


	vel_pub_ = nh_.advertise<turtlesim::Velocity>("turtle1/command_velocity", 1);


	joy_sub_ = nh_.subscribe<sensor_msgs::Joy>("joy", 10, &TeleopTurtle::joyCallback, this);
}
void TeleopTurtle::joyCallback(const sensor_msgs::Joy::ConstPtr& joy)
{
  turtlesim::Velocity vel;
  vel.angular = a_scale_*joy->axes[angular_];
  vel.linear = l_scale_*joy->axes[linear_];
  vel_pub_.publish(vel);
}


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

  ros::spin();
}