Steps

1. Create Message

   bash roscd thorlabs_linear_actuator/ mkdir msg cd msg nano write.msg

2. Paste in the following, save, then close:

   txt uint8 register uint8 value

3. open package.xml

   bash roscd thorlabs_linear_actuator/ nano package.xml

4. paste in the following, save, then close:

   xml <build_depend>message_generation</build_depend> <exec_depend>message_runtime</exec_depend>

5. Open CMakeLists.txt in your favorite text editor (rosed from the previous tutorial is a good option).

   1. Add the message_generation dependency to the find_package call which already exists in your CMakeLists.txt so that you can generate messages. You can do this by simply adding message_generation to the list of COMPONENTS such that it looks like this:

      ```

      Do not just add this to your CMakeLists.txt, modify the existing text to add message_generation before the closing parenthesis

      find_package(catkin REQUIRED COMPONENTS roscpp rospy std_msgs message_generation ) ```

   2. Also make sure you export the message runtime dependency.

      txt catkin_package( ... CATKIN_DEPENDS message_runtime ... ...)

   3. Find the following block of code:

      ```txt

      add_message_files(

      FILES

      Message1.msg

      Message2.msg

      )

      ```

   4. Uncomment it by removing the # symbols and then replace the stand in Message*.msg files with your .msg file, such that it looks like this:

      txt add_message_files( FILES write.msg )

      By adding the .msg files manually, we make sure that CMake knows when it has to reconfigure the project after you add other .msg files.

   5. Now we must ensure the generate_messages() function is called.

      For ROS Hydro and later, you need to uncomment these lines:

      ```txt

      generate_messages(

      DEPENDENCIES

      std_msgs

      )

      ```

1. Check message

   bash rosmsg show thorlabs_linear_actuator/write

2. Make

   ```bash cd ~/code/code_idealab_ros/ catkin_make

   catkin_make install # (optionally)

   make one thing

   catkin_make --source my_src

   catkin_make install --source my_src # (optionally)

   ```