I followed the Read.me instructions at https://github.com/ros-drivers/leap_motion
After I run command source ~catkin_ws/devel/setup.bash && rosrun leap_motion sender.pyI do receive data running on the terminal.
However, when I try rostopic echo /leapmotion/data, it throws an error:
ysu66@mech1331:~$ rostopic echo /leapmotion/data
ERROR: Cannot load message class for [leap_motion/leapros]. Are your messages built?
Can you please show me how to fix it? Btw, I am running it on Ubuntu machine