Document node parameters and add config-file based launch

CMakeLists.txt

@@ -112,4 +112,27 @@ install(DIRECTORY
 # Scripts Block [END] #
 #######################
 
+########################
+# Launch Block [BEGIN] #
+# vvvvvvvvvvvvvvvvvvvv #
+# According to https://github.com/SmartArmStack/sas_robot_driver/blob/ros2/CMakeLists.txt
+install(DIRECTORY
+        launch
+        DESTINATION share/${PROJECT_NAME}/
+)
+# ^^^^^^^^^^^^^^^^^^ #
+# Launch Block [END] #
+######################
+
+#########################
+# Config Block [BEGIN] #
+# vvvvvvvvvvvvvvvvvvvvv #
+install(DIRECTORY
+        config
+        DESTINATION share/${PROJECT_NAME}/
+)
+# ^^^^^^^^^^^^^^^^^^^ #
+# Config Block [END] #
+#######################
+
 ament_package()

README.md

@@ -10,6 +10,32 @@
 - `src/` — library and pybind11 bindings.
 - `sas_force_sensor/` — Python package (thin wrapper around the pybind11 module).
 - `scripts/` — Python example script.
+- `launch/` — example launch file for the sinusoidal force sensor node.
+- `config/` — example parameter configuration file.
+
+## ROS 2 Nodes & Parameters
+
+The package is primarily a library. It also provides one example node.
+
+### Node: `sinusoidal_force_sensor`
+
+| Property | Value |
+|---|---|
+| **Executable** | `sinusoidal_force_sensor` |
+| **ROS node name** | `sinusoidal_force_sensor` (set by the `name` launch argument of `sinusoidal_force_sensor_launch.py`) |
+| **Description** | Example node that publishes a sinusoidal force/torque wrench on `<node_name>/get/wrench` via `ForceSensorServer`. |
+
+#### Parameters
+
+The node currently declares **no ROS parameters** — the amplitude, frequency, and tick rate are hardcoded constants in `src/examples/sinusoidal_force_sensor.cpp`.
+
+#### Sample launch
+
+```console
+ros2 launch sas_force_sensor sinusoidal_force_sensor_launch.py
+```
+
+The launch file loads the (currently empty) parameter block from `config/config.yaml` (override with `config_file:=/path/to/config.yaml`) so the node follows the standard SmartArmStack config-file pattern.
 
 ## Client–Server pair
 

config/config.yaml

@@ -0,0 +1,11 @@
+# Parameters for the sas_force_sensor nodes.
+#
+# Each top-level block is keyed by the ROS node name and is loaded by the
+# corresponding launch file via its `config_file` argument.
+
+# sinusoidal_force_sensor (example node)
+sinusoidal_force_sensor:
+  ros__parameters: {}
+    # The example sinusoidal force sensor declares no ROS parameters today.
+    # This block is kept so the node can be configured through the standard
+    # SmartArmStack config-file pattern once parameters are introduced.

launch/sinusoidal_force_sensor_launch.py

@@ -0,0 +1,34 @@
+import os.path
+
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    """Launch the example sinusoidal force sensor node.
+
+    Parameters are loaded from a YAML configuration file. Pass a different
+    file with ``config_file:=/path/to/config.yaml``.
+    """
+    name = LaunchConfiguration('name')
+    config_file = LaunchConfiguration('config_file')
+
+    return LaunchDescription([
+        DeclareLaunchArgument(
+            'name',
+            default_value='sinusoidal_force_sensor'
+        ),
+        DeclareLaunchArgument(
+            'config_file',
+            default_value=os.path.join(get_package_share_directory('sas_force_sensor'), 'config', 'config.yaml')
+        ),
+        Node(
+            package='sas_force_sensor',
+            executable='sinusoidal_force_sensor',
+            name=name,
+            parameters=[config_file]
+        )
+    ])