首页 > 代码库 > ROS+mbed
ROS+mbed
试了一下, 用stm32F103RB nucleo的板子, 跑mbed, 跟ros的库, 发布一个std_msg/String, 为什么不直接发布里程? 因为经常报message比buffer大的错误.
没办法, 只好先用stm32通过串口, 发布有用的x, y, 跟yaw值, string格式, 然后ROS端起一个节点去解析string, 转成里程跟tf.
stm32端:
/* * rosserial Publisher Example * Prints "hello world!" */ #include "mbed.h" #include <ros.h> #include <string> #include <std_msgs/String.h> #include <sstream> ros::NodeHandle nh; std_msgs::String str_msg; ros::Publisher chatter("chatter", &str_msg); char hello[100] = "hello, shit world!"; DigitalOut led = LED1; int counter = 0; int main() { nh.initNode(); nh.advertise(chatter); while (1) { std::stringstream ss; //counter++; led = !led; ss << "pos:x=" << counter <<",y="<< counter++ <<",r=" << counter++; //counter++; //ss << "y=" << counter; //counter++; //ss << "r=" << counter; const std::string tmp = ss.str(); const char* cstr = tmp.c_str(); str_msg.data=cstr; //str_msg.data=http://www.mamicode.com/hello; chatter.publish( &str_msg ); nh.spinOnce(); wait_ms(1000); } }
这里的x,y,yaw(写错成r了)都是虚拟数据, 不是真实的.
接着是ROS端起节点:
#include "ros/ros.h" #include <string> #include "std_msgs/String.h" #include <tf/transform_broadcaster.h> #include <nav_msgs/Odometry.h> #include <vector> #include <stdlib.h> #include <sstream> ros::Time current_time, last_time; ros::Publisher odom_pub; void split(const std::string& src, const std::string& separator, std::vector<std::string>& dest) { std::string str = src; std::string substring; std::string::size_type start = 0, index; do { index = str.find_first_of(separator,start); if (index != std::string::npos) { substring = str.substr(start,index-start); dest.push_back(substring); start = str.find_first_not_of(separator,index); if (start == std::string::npos) return; } }while(index != std::string::npos); //the last token substring = str.substr(start); dest.push_back(substring); } void processTest(const std_msgs::String::ConstPtr& msg){ //char src[] = "Accsvr:tcp -h : 127.0.0.1 -p \t 20018 "; const char* base_message = msg->data.c_str(); printf("Origin str: %s\n\r",base_message); std::string originStr(base_message); const int len = originStr.length(); char* originChar= new char[len+1]; strcpy(originChar,originStr.c_str()); const char *d = ","; char *p; p = strtok(originChar,d); char * charX = p + 6; // = sprintf(charX, "%05X", 30); int intX; std::stringstream ss; ss << charX; ss >> intX; printf("x: %d\n",intX); p = strtok(NULL,d); int intY; char * charY = p + 2; ss.clear(); ss << charY; ss >> intY; printf("y: %d\n",intY); p = strtok(NULL,d); int intYaw; char * charYaw = p + 2; ss.clear(); ss << charYaw; ss >> intYaw; printf("intYaw: %d\n",intYaw); //p = strtok(NULL,d); //int intX = std::atio(std::string(charX)); //while(p) //{} //printf("p: %s\n",p); //printf("x: %s\n",charX); //printf("x: %d\n",intX); //p=strtok(NULL,d); } void processStr(const std_msgs::String::ConstPtr& msg) { int splitter =‘x‘; char *pdest; const char* base_message = msg->data.c_str(); printf("Origin str: %s\n\r",base_message); std::string originStr(base_message); char* originChar; char* charx; char* chary; char* charr; const int len = originStr.length(); originChar = new char[len+1]; strcpy(originChar,originStr.c_str()); int result; pdest = strchr(originChar, splitter); printf("pdest is %s\n",pdest); result = pdest - originChar + 1; if( pdest != NULL ){ printf("Result:\tfirst %c found at position %d\n", splitter, result ); } //printf("pdest is %s\n",pdest); } geometry_msgs::TransformStamped odom_trans; void chatterCallback(const std_msgs::String::ConstPtr& msg) { //printf("Origin str: %s\n\r",base_message); std::string base_message = msg->data.c_str(); //printf("Origin str: %s\n\r",base_message); //processStr(msg); //const char* base_message = msg->data.c_str(); processTest(msg); //ROS_INFO("I heard: [%s]", base_message); ros::NodeHandle n; current_time = ros::Time::now(); nav_msgs::Odometry odom; double x = 0.0; double y = 0.0; double th = 0.0; double vx = 0.1; double vy = -0.1; double vth = 0.1; double dt = (current_time - last_time).toSec(); double delta_x = (vx * cos(th) - vy * sin(th)) * dt; double delta_y = (vx * sin(th) + vy * cos(th)) * dt; double delta_th = vth * dt; x += delta_x; y += delta_y; th += delta_th; geometry_msgs::Quaternion odom_quat = tf::createQuaternionMsgFromYaw(th); //first, we‘ll publish the transform over tf odom_trans.header.stamp = current_time; odom_trans.header.frame_id = "odom"; odom_trans.child_frame_id = "base_link"; odom_trans.transform.translation.x = x; odom_trans.transform.translation.y = y; odom_trans.transform.translation.z = 0.0; odom_trans.transform.rotation = odom_quat; //send the transform //next, we‘ll publish the odometry message over ROS odom.header.stamp = current_time; odom.header.frame_id = "odom"; //set the position odom.pose.pose.position.x = x; odom.pose.pose.position.y = y; odom.pose.pose.position.z = 0.0; odom.pose.pose.orientation = odom_quat; //set the velocity odom.child_frame_id = "base_link"; odom.twist.twist.linear.x = vx; odom.twist.twist.linear.y = vy; odom.twist.twist.angular.z = vth; //publish the message odom_pub.publish(odom); last_time = current_time; } int main(int argc, char **argv) { ros::init(argc, argv, "listener"); ros::NodeHandle n; ros::Subscriber sub = n.subscribe("chatter", 1000, chatterCallback); odom_pub = n.advertise<nav_msgs::Odometry>("odom", 50); tf::TransformBroadcaster odom_broadcaster; ros::Rate r(100.0); //ros::spin(); while(n.ok()){ odom_broadcaster.sendTransform(odom_trans); ros::spinOnce(); r.sleep(); } return 0; }
这个节点的功能就是:
1. 起一个订阅者, 订阅stm32发过来的chatter主题.
2. 收到topic的回调中, 处理字符串, 变成int格式(后期应该是float格式吧).
3. 处理完字符串之后, 拼成里程数据, 发布tf跟里程.
ROS+mbed
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。