Clarify CAN bridge dependency

CHANGELOG.rst

@@ -10,7 +10,8 @@ Forthcoming
 * Add startup confirmation, feedback timeout handling, repeated shutdown
   commands, and a motor-side CAN watchdog.
 * Add compatibility with ROS 2 Humble, Jazzy, Kilted, Lyrical, and Rolling.
-* Use ros2_socketcan topics for CAN transport.
+* Use ``can_msgs/msg/Frame`` topics for CAN transport; the example launch uses
+  ``ros2_socketcan`` as its bridge.
 * Move periodic motion-frame publication to a latest-value transport thread so
   the controller update loop cannot accumulate stale commands before DDS publication.
 * Serialize all outbound frames through one DDS DataWriter and invalidate

README.ja.md

@@ -1,7 +1,7 @@
 # robstride_ros2
 
 RobStrideアクチュエータをprivate CAN protocolで制御する、非公式・コミュニティ管理のROS 2 `ros2_control` Hardware Componentです。
-CAN frameの送受信には[`ros2_socketcan`](https://github.com/autowarefoundation/ros2_socketcan)が提供する`can_msgs/msg/Frame` topicを使用します。
+CAN frameの送受信には`can_msgs/msg/Frame` topicを使用します。core packageは`can_msgs`に依存し、特定のSocketCAN bridgeを必要としません。
 
 本プロジェクトはRobStride社とは提携しておらず、同社による承認を受けたものではありません。protocolと型番別profileは、RobStride公式[`Product_Information`](https://github.com/RobStride/Product_Information) repositoryの英語版manualと照合しています。英語版READMEは[`README.md`](README.md)を参照してください。
 
@@ -22,13 +22,23 @@ repositoryには4つのROS 2 packageが含まれます。
 
 | package | 役割 |
 |---|---|
-| `robstride_driver` | CAN通信、モーター指令、feedback、復旧処理 |
+| `robstride_driver` | private protocolと`can_msgs` topic transport |
 | `robstride_ros2_control` | `ros2_control` Hardware Component |
 | `robstride_examples` | 型番別Xacro、controller設定、example launch |
 | `robstride_ros2` | 上記packageをまとめてインストールするaggregate package |
 
 既存のrobot descriptionとの互換性を保つため、plugin IDは`robstride_ros2/RobStrideSystem`を使用します。
 
+## CAN bridgeとの互換性
+
+`robstride_driver`と`robstride_ros2_control`は`can_msgs/msg/Frame` topicだけを使って通信します。互換性のある送受信topicを提供するCAN bridgeであれば、`ros2_socketcan`以外とも組み合わせられます。
+
+[`ros2_socketcan`](https://github.com/autowarefoundation/ros2_socketcan)へ直接依存するのは、そのbridgeを起動するlaunchを含む`robstride_examples`だけです。aggregate packageの`robstride_ros2`はexampleもまとめてインストールします。bridge非依存のHardware Componentとdriverだけをインストールする場合は、`robstride_ros2_control`までをbuildします。
+
+```bash
+colcon build --packages-up-to robstride_ros2_control --symlink-install
+```
+
 ## 対応ROS 2ディストリビューション
 
 同じsource branchで以下のROS 2ディストリビューションに対応し、それぞれのTier 1 Ubuntu環境でCIを実行します。
@@ -110,8 +120,8 @@ ros2 topic pub --rate 20 \
 | parameter | default | 説明 |
 |---|---:|---|
 | `host_can_id` | `253` | host CAN ID。範囲は`0..255` |
-| `can_tx_topic` | `to_can_bus` | `ros2_socketcan`へ送るframeのtopic |
-| `can_rx_topic` | `from_can_bus` | `ros2_socketcan`から受け取るframeのtopic |
+| `can_tx_topic` | `to_can_bus` | 送信する`can_msgs/msg/Frame` topic |
+| `can_rx_topic` | `from_can_bus` | 受信する`can_msgs/msg/Frame` topic |
 | `can_rx_qos_depth` | `32` | reliable・volatileなfeedback QoS depth。多数のモーターを使う場合は増加を検討 |
 | `feedback_timeout_ms` | `3000` | feedbackを受信できない状態でERRORを返すまでの時間 |
 | `fail_on_feedback_timeout` | `true` | feedback timeout時にHardwareを停止 |
@@ -122,7 +132,7 @@ ros2 topic pub --rate 20 \
 | `shutdown_stop_repetitions` | `3` | 終了時にゼロ指令と停止指令を送る回数 |
 | `shutdown_stop_interval_ms` | `20` | ゼロ指令と停止指令の送信セット間隔 |
 | `shutdown_confirmation_timeout_ms` | `300` | Reset modeのfeedbackを待つ時間。`0`で確認を無効化 |
-| `startup_connection_timeout_ms` | `3000` | `ros2_socketcan`のtopic endpointを待つ時間 |
+| `startup_connection_timeout_ms` | `3000` | CAN bridgeのtopic endpointを待つ時間 |
 | `startup_confirmation_timeout_ms` | `500` | parameterと有効化確認の1試行あたりのtimeout |
 | `startup_retries` | `3` | 起動時のparameter設定と有効化の最大試行回数 |
 

README.md

@@ -2,8 +2,8 @@
 
 An unofficial, community-maintained ROS 2 `ros2_control` hardware component for
 RobStride actuators using the RobStride private CAN protocol.
-CAN frames are exchanged through the `can_msgs/msg/Frame` topics provided by
-[`ros2_socketcan`](https://github.com/autowarefoundation/ros2_socketcan).
+CAN frames are exchanged through `can_msgs/msg/Frame` topics. The core packages
+depend on `can_msgs` and do not require a specific SocketCAN bridge.
 
 This project is not affiliated with or endorsed by RobStride. The protocol and
 model profiles were checked against the English manuals in RobStride's official
@@ -28,14 +28,30 @@ The repository contains four ROS 2 packages:
 
 | Package | Responsibility |
 |---|---|
-| `robstride_driver` | CAN communication, motor commands, feedback, and recovery |
+| `robstride_driver` | Private protocol and `can_msgs` topic transport |
 | `robstride_ros2_control` | `ros2_control` Hardware Component |
 | `robstride_examples` | Motor-profile Xacro, controller configuration, and example launch |
 | `robstride_ros2` | Installs the complete set of packages |
 
 The plugin identifier `robstride_ros2/RobStrideSystem` remains compatible with
 existing robot descriptions.
 
+## CAN bridge compatibility
+
+`robstride_driver` and `robstride_ros2_control` communicate only through
+`can_msgs/msg/Frame` topics. They can be used with any CAN bridge that provides
+compatible transmit and receive topics.
+
+`robstride_examples` is the only package that directly depends on
+[`ros2_socketcan`](https://github.com/autowarefoundation/ros2_socketcan), because
+its example launch starts that bridge. The aggregate `robstride_ros2` package
+installs the examples as well. To install only the bridge-independent Hardware
+Component and driver, build through `robstride_ros2_control`:
+
+```bash
+colcon build --packages-up-to robstride_ros2_control --symlink-install
+```
+
 ## Supported ROS 2 distributions
 
 The same source branch targets all currently supported ROS 2 distributions.
@@ -133,8 +149,8 @@ description.
 | Parameter | Default | Description |
 |---|---:|---|
 | `host_can_id` | `253` | Host CAN ID in the range `0..255` |
-| `can_tx_topic` | `to_can_bus` | Frames sent to `ros2_socketcan` |
-| `can_rx_topic` | `from_can_bus` | Frames received from `ros2_socketcan` |
+| `can_tx_topic` | `to_can_bus` | Outgoing `can_msgs/msg/Frame` topic |
+| `can_rx_topic` | `from_can_bus` | Incoming `can_msgs/msg/Frame` topic |
 | `can_rx_qos_depth` | `32` | Reliable, volatile feedback QoS depth; increase for large motor groups |
 | `feedback_timeout_ms` | `3000` | Maximum time without motor feedback before returning ERROR |
 | `fail_on_feedback_timeout` | `true` | Stop the hardware when feedback times out |
@@ -145,7 +161,7 @@ description.
 | `shutdown_stop_repetitions` | `3` | Number of zero and stop commands sent at shutdown |
 | `shutdown_stop_interval_ms` | `20` | Delay between repeated shutdown frames |
 | `shutdown_confirmation_timeout_ms` | `300` | Wait for Reset mode feedback; `0` disables confirmation |
-| `startup_connection_timeout_ms` | `3000` | Wait for the `ros2_socketcan` topic endpoints |
+| `startup_connection_timeout_ms` | `3000` | Wait for the CAN bridge topic endpoints |
 | `startup_confirmation_timeout_ms` | `500` | Per-attempt parameter and enable confirmation timeout |
 | `startup_retries` | `3` | Number of startup parameter and enable attempts |
 

robstride_driver/src/driver.cpp

@@ -92,7 +92,7 @@ bool RobStrideDriver::start()
 {
   if (!transport_ || !transport_->wait_for_endpoints(settings_.connection_timeout)) {
     RCLCPP_ERROR(
-      logger_, "Timed out waiting for ros2_socketcan endpoints on '%s' and '%s'",
+      logger_, "Timed out waiting for CAN bridge endpoints on '%s' and '%s'",
       settings_.transport.transmit_topic.c_str(), settings_.transport.receive_topic.c_str());
     return false;
   }

robstride_ros2_control/robstride_hardware.xml

@@ -3,6 +3,6 @@
     name="robstride_ros2/RobStrideSystem"
     type="robstride_ros2_control::RobStrideSystem"
     base_class_type="hardware_interface::SystemInterface">
-    <description>RobStride private-CAN protocol system using ros2_socketcan topics.</description>
+    <description>RobStride private-CAN protocol system using can_msgs topics.</description>
   </class>
 </library>