The ROS stack for interfacing the Dynamixel motor is dynamixel_motor. This stack contains interface for Dynamixel motors such as MX-28, MX64, MX-106, RX-28, RX64, EX106, AX-12, and AX-18. The stack consists of the following packages:

• dynamixel_driver: This package is the driver package of Dynamixel, which can do low level IO communication with Dynamixel from PC. This driver has hardware interface for the previously mentioned series of servos and can do the read /write operation to Dynamixel through this package. This package is used by high level packages such as dynamixel_controllers. There are only few cases when the user directly interacts with this package.
• dynamixel_controllers: This is a higher level package that works using the dynamixel_motor package. Using this package, we can create a ROS controller for each Dynamixel joint of the robot. The package contains a configurable node, services, and spawner script to start, stop, and restart one or more controller plugins. In each controller, we can set the speed and the torque. Each Dynamixel controller can be configured using the ROS parameters or can be loaded by a YAML file. The dynamixel_controllers packages support the following kinds of controllers:
  • Joint Position controllers
  • Joint Torque controllers
  • Joint Trajectory Action controller
• dynamixel_msgs: These are the message definitions which are used inside the dynamixel_motor stack.