Now, we can define the actuator information for all of the links. The actuator macro is defined in the robot_arm_essentials.xacro file, as shown here:

<xacro:macro name="arm_transmission" params="prefix ">
 
 <transmission name="${prefix}_trans" type="SimpleTransmission">
   <type>transmission_interface/SimpleTransmission</type>
   <actuator name="${prefix}_motor">
    <hardwareInterface>hardware_interface/PositionJointInterface</hardwareInterface>
    <mechanicalReduction>1</mechanicalReduction>
   </actuator>
   <joint name="${prefix}_joint">
    <hardwareInterface>hardware_interface/PositionJointInterface</hardwareInterface>
   </joint>
 </transmission>
 
 </xacro:macro>

Call them in the robot arm file as follows:

<xacro:arm_transmission prefix="arm_base"/>
<xacro:arm_transmission prefix="shoulder"/>
<xacro:arm_transmission prefix="bottom_wrist"/>
<xacro:arm_transmission prefix="elbow"/>
<xacro:arm_transmission prefix="top_wrist"/>

Now that the mechanisms have been called, let's call the controllers that use them and make our robot dynamic.