Document node parameters and switch to config-file based launch

README.md

@@ -46,13 +46,53 @@ chmod +x install.sh && . install.sh
 ## Running sensor server
 
 ```console
-ros2 launch sas_force_sensor_bota sas_force_sensor_bota_launch.py
+ros2 launch sas_force_sensor_bota force_sensor_launch.py
 ```
 
+The launch file loads the parameters from `config/config.yaml` (override with
+`config_file:=/path/to/config.yaml`). The hardware-specific JSON configuration
+(`configuration_file_path`) is embedded in the YAML file: `config/config.yaml`
+points at `bota_binary_gen0.json` and `config/config_ethercat.yaml` points at
+`ethercat_gen0.json` (for the EtherCAT hardware).
+
 | Configurable Parameter | Meaning |
 |------------------------|---------|
-|`topic_name`| Topic prefix, for instance, if there are multiple sensors in the same `ROS_DOMAIN`.|
-|`configuration_file_path`| The path to the `json` configuration file, see examples in the `config` folder.|
+| `config_file` (launch argument) | Path to the YAML configuration file. Defaults to `config/config.yaml`; use `config_ethercat.yaml` for the EtherCAT hardware. |
+
+## ROS 2 Nodes & Parameters
+
+### Node: `sas_force_sensor_bota_node`
+
+| Property | Value |
+|---|---|
+| **Executable** | `sas_force_sensor_bota_node` |
+| **ROS node name** | `sas_force_sensor_bota_node` (set by the `name` launch argument of `force_sensor_launch.py`) |
+| **Description** | Reads the Bota force/torque sensor, publishes the wrench on `<topic_name>/get/wrench`, and keeps the sensor configured/activated for the node lifetime. |
+
+#### Parameters
+
+| Parameter | Type | Mandatory / Optional | Default | Purpose |
+|---|---|---|---|---|
+| `topic_name` | string | Optional | `/sas_force_sensor_bota` | Topic prefix; e.g. when there are multiple sensors in the same `ROS_DOMAIN` |
+| `configuration_file_path` | string | Optional | in-code default pointing at `config/bota_binary_gen0.json` in the package share directory | Path to the Bota JSON configuration file (hardware-specific). May be given as an absolute path or as a filename relative to the package `config/` directory (as in the sample YAML files) |
+| `sampling_time` | double | Optional | `0.01` | Sampling period of the read loop, in seconds |
+
+**How mandatory/optional is determined in code:**
+- **Mandatory** params are declared without a default — the node fails if they are not provided.
+- **Optional** params are declared with an in-code default.
+
+#### Sample launch
+
+```console
+ros2 launch sas_force_sensor_bota force_sensor_launch.py
+```
+
+To use the EtherCAT JSON configuration (select the EtherCAT YAML, which
+embeds `configuration_file_path: ethercat_gen0.json`):
+
+```console
+ros2 launch sas_force_sensor_bota force_sensor_launch.py config_file:=$(ros2 pkg prefix sas_force_sensor_bota --share)/config/config_ethercat.yaml
+```
 
 ## Example client
 

config/config.yaml

@@ -0,0 +1,13 @@
+# Parameters for the sas_force_sensor_bota node.
+#
+# Loaded by force_sensor_launch.py via its `config_file` argument. The
+# hardware-specific `configuration_file_path` (a JSON file in this directory)
+# is embedded here; use config_ethercat.yaml for the EtherCAT hardware.
+
+# sas_force_sensor_bota_node
+sas_force_sensor_bota_node:
+  ros__parameters:
+    topic_name: '/sas_force_sensor_bota'
+    # Relative to the package config/ directory; absolute paths are also accepted.
+    configuration_file_path: 'bota_binary_gen0.json'
+    sampling_time: 0.01  # 100 Hz

config/config_ethercat.yaml

@@ -0,0 +1,13 @@
+# Parameters for the sas_force_sensor_bota node — EtherCAT hardware variant.
+#
+# Loaded by force_sensor_launch.py via its `config_file` argument
+# (config_file:=.../config_ethercat.yaml). The only difference from
+# config.yaml is the hardware-specific `configuration_file_path`.
+
+# sas_force_sensor_bota_node
+sas_force_sensor_bota_node:
+  ros__parameters:
+    topic_name: '/sas_force_sensor_bota'
+    # Relative to the package config/ directory; absolute paths are also accepted.
+    configuration_file_path: 'ethercat_gen0.json'
+    sampling_time: 0.01  # 100 Hz

docker/compose.yml

@@ -15,7 +15,7 @@ services:
       cd /root/sas_force_sensor_bota_devel
       && colcon build
       && source install/setup.bash
-      && timeout -s INT $$TIMEOUT ros2 launch sas_force_sensor_bota sas_force_sensor_bota_launch.py"
+      && timeout -s INT $$TIMEOUT ros2 launch sas_force_sensor_bota force_sensor_launch.py"
 
   sas_force_sensor_bota_client:
     build:

docker/compose_ethercat.yml

@@ -15,7 +15,7 @@ services:
       cd /root/sas_force_sensor_bota_devel
       && colcon build
       && source install/setup.bash
-      && timeout -s INT $$TIMEOUT ros2 launch sas_force_sensor_bota sas_force_sensor_bota_launch.py configuration_file_path:=/root/sas_force_sensor_bota_devel/src/sas_force_sensor_bota/config/ethercat_gen0.json"
+      && timeout -s INT $$TIMEOUT ros2 launch sas_force_sensor_bota force_sensor_launch.py config_file:=$$(ros2 pkg prefix sas_force_sensor_bota --share)/config/config_ethercat.yaml"
 
   sas_force_sensor_bota_client:
     build: .

docker/demo/compose.yml

@@ -15,7 +15,7 @@ services:
       && chmod +x install.sh
       && . install.sh
       && source /opt/ros/jazzy/setup.bash
-      && timeout -s INT $$TIMEOUT ros2 launch sas_force_sensor_bota sas_force_sensor_bota_launch.py"
+      && timeout -s INT $$TIMEOUT ros2 launch sas_force_sensor_bota force_sensor_launch.py"
 
   sas_force_sensor_bota_client:
     image: murilomarinho/sas:jazzy

launch/force_sensor_launch.py

@@ -0,0 +1,39 @@
+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 Bota force sensor node.
+
+    Parameters are loaded from a YAML configuration file. Pass a different
+    file with ``config_file:=/path/to/config.yaml`` (e.g.
+    ``config_ethercat.yaml`` for the EtherCAT hardware). The
+    hardware-specific ``configuration_file_path`` (a JSON file in ``config/``)
+    is embedded in the YAML configuration file.
+    """
+    name = LaunchConfiguration('name')
+    config_file = LaunchConfiguration('config_file')
+
+    return LaunchDescription([
+        DeclareLaunchArgument(
+            'name',
+            default_value='sas_force_sensor_bota_node'
+        ),
+        DeclareLaunchArgument(
+            'config_file',
+            default_value=os.path.join(get_package_share_directory('sas_force_sensor_bota'), 'config', 'config.yaml')
+        ),
+        Node(
+            package='sas_force_sensor_bota',
+            executable='sas_force_sensor_bota_node',
+            output='screen',
+            emulate_tty=True,
+            name=name,
+            parameters=[config_file]
+        )
+    ])

sas_force_sensor_bota/force_sensor_bota.py

@@ -8,6 +8,7 @@
 You should have received a copy of the GNU General Public License along with this program. If not,
 see <https://www.gnu.org/licenses/>.
 """
+import os.path
 import pathlib
 import bota_driver
 
@@ -26,11 +27,18 @@ def __init__(self):
 
         this_package_share_directory = get_package_share_directory('sas_force_sensor_bota')
         default_configuration_file_path = str(this_package_share_directory / pathlib.Path("config") / pathlib.Path(
-            "../config/bota_binary_gen0.json"))
+            "bota_binary_gen0.json"))
 
         self.declare_parameter('configuration_file_path', default_configuration_file_path)
         configuration_file_path = self.get_parameter('configuration_file_path').get_parameter_value().string_value
 
+        # A path relative to the package config/ directory (as in the sample
+        # YAML configurations) is resolved against that directory. Absolute
+        # paths are used as given.
+        if not os.path.isabs(configuration_file_path):
+            configuration_file_path = str(this_package_share_directory / pathlib.Path("config") / pathlib.Path(
+                configuration_file_path))
+
         self.declare_parameter('sampling_time', 0.01)
         sampling_time = self.get_parameter('sampling_time').get_parameter_value().double_value
 

setup.py

@@ -13,7 +13,8 @@
             ['resource/' + package_name]),
         ('share/' + package_name, ['package.xml']),
         (os.path.join('share', package_name, 'launch'), glob(os.path.join('launch', '*launch.[pxy][yma]*'))),
-        (os.path.join('share', package_name, 'config'), glob(os.path.join('config', '*.json')))
+        (os.path.join('share', package_name, 'config'), glob(os.path.join('config', '*.json'))),
+        (os.path.join('share', package_name, 'config'), glob(os.path.join('config', '*.yaml')))
     ],
     install_requires=['setuptools'],
     zip_safe=True,