Hello,<br><br>sorry if this is a basic question but I couldn't find anything in the wiki. I would like to retrieve the current value of a topic from the callback of another topic. How is this possible? In more detail I have:<br>
<br>public:<br> ImageConverter(ros::NodeHandle &n) : n_(n), it_(n_)<br> {<br> cvNamedWindow("Image window");<br> image_sub_ = it_.subscribe("/camera_sim/image_raw", 1, &ImageConverter::imageCallback, this);<br>
}<br><br>void imageCallback(const sensor_msgs::ImageConstPtr& msg_ptr)<br>{<br> // Image obtained from subscribed node and converted to IplImage<br> IplImage *img = NULL;<br> try {<br> img = bridge_.imgMsgToCv(msg_ptr, "bgr8"); // reads the image<br>
// I WOULD LIKE TO READ THE VALUE OF ANOTHER TOPIC (std_msgs::String) HERE<br> }<br> catch (sensor_msgs::CvBridgeException error) {<br> ROS_ERROR("error");<br> }<br>}<br>
<br>Many Thanks<br>