[转]ROS订阅激光数据

https://github.com/robopeak/rplidar_ros/blob/master/src/client.cpp

/*
	* Copyright (c) 2014, RoboPeak
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	*
	* 2. Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
	* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
	* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
	* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	*/
	/*
	* RoboPeak LIDAR System
	* RPlidar ROS Node client test app
	*
	* Copyright 2009 - 2014 RoboPeak Team
	* http://www.robopeak.com
	*
	*/
	#include "ros/ros.h"
	#include "sensor_msgs/LaserScan.h"
	#define RAD2DEG(x) ((x)*180./M_PI)
	void scanCallback(const sensor_msgs::LaserScan::ConstPtr& scan)
	{
	int count = scan->scan_time / scan->time_increment;
	ROS_INFO("I heard a laser scan %s[%d]:", scan->header.frame_id.c_str(), count);
	ROS_INFO("angle_range, %f, %f", RAD2DEG(scan->angle_min), RAD2DEG(scan->angle_max));
	for(int i = 0; i < count; i++) {
	float degree = RAD2DEG(scan->angle_min + scan->angle_increment * i);
	ROS_INFO(": [%f, %f]", degree, scan->ranges[i]);
	}
	}
	int main(int argc, char **argv)
	{
	ros::init(argc, argv, "rplidar_node_client");
	ros::NodeHandle n;
	ros::Subscriber sub = n.subscribe<sensor_msgs::LaserScan>("/scan", 1000, scanCallback);
	ros::spin();
	return 0;
	}