Hi, I'm new to ROS and I am trying to make a Pioneer 2 robot move through different points on a map. The first thing I need to do is to place AR tags on the floor and, using a USB/Wireless camera, being able to detect their coordinates so I can make my robot travel. I have found some packages such as uvccamera and artrack_alvar but couldn't figure out how to write a code to make this happen. Does anyone have some code examples so I can figure this out and move on? Thank you