All codes for Arduino Mega 2560 board and dynamixel in case of U2D2 failure.
Download Arduino library for dynamixel : Dynamixel2Arduino
Install rosserial :
sudo apt-get install ros-indigo-rosserial-arduino
sudo apt-get install ros-indigo-rosserial
rosrun rosserial_arduino make_libraries.py .
1. roscore
2. rosrun rosserial_python serial_node.py _port:=/dev/ttyUSB0 _baud:=57600
3. rosrun move_group subscriber.py