(tested) 將 commandLong 的 ros2 service 包裝為一個函式庫 changeMode 並附上一個臨時範例

src/fc_network_apps/__init__.py

@@ -0,0 +1,3 @@
+from .changeMode import ChangeModeClient, ChangeModeResult, change_mode
+
+__all__ = ["ChangeModeClient", "ChangeModeResult", "change_mode"]

src/fc_network_apps/changeMode.py

@@ -0,0 +1,127 @@
+"""Simple wrapper for mode change via fc_network ROS2 service.
+
+Reference CLI command:
+ros2 service call /fc_network/vehicle/send_command_long \
+  fc_interfaces/srv/MavCommandLong \
+  "{target_sysid: 3, target_compid: 0, command: 176, confirmation: 0, \
+    param1: 1, param2: 4, param3: 0, param4: 0, param5: 0, param6: 0, \
+    param7: 0, timeout_sec: 2}"
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from typing import Optional
+
+import rclpy
+from rclpy.node import Node
+
+from fc_interfaces.srv import MavCommandLong
+
+COMMAND_DO_SET_MODE = 176
+DEFAULT_SERVICE_NAME = "/fc_network/vehicle/send_command_long"
+DEFAULT_TIMEOUT_SEC = 2.0
+
+
+@dataclass
+class ChangeModeResult:
+    """Return value for mode change requests."""
+
+    success: bool
+    message: str
+    ack_result: int
+
+
+class ChangeModeClient(Node):
+    """Small ROS2 client dedicated to change flight mode."""
+
+    def __init__(self, service_name: str = DEFAULT_SERVICE_NAME) -> None:
+        super().__init__("fc_change_mode_client")
+        self._client = self.create_client(MavCommandLong, service_name)
+
+    def wait_for_service(self, timeout_sec: float = 3.0) -> bool:
+        return self._client.wait_for_service(timeout_sec=timeout_sec)
+
+    def change_mode(
+        self,
+        *,
+        target_sysid: int,
+        custom_mode: float,
+        target_compid: int = 0,
+        base_mode: float = 1.0,
+        confirmation: int = 0,
+        timeout_sec: float = DEFAULT_TIMEOUT_SEC,
+    ) -> ChangeModeResult:
+        req = MavCommandLong.Request()
+        req.target_sysid = target_sysid
+        req.target_compid = target_compid
+        req.command = COMMAND_DO_SET_MODE
+        req.confirmation = confirmation
+        req.param1 = float(base_mode)
+        req.param2 = float(custom_mode)
+        req.param3 = 0.0
+        req.param4 = 0.0
+        req.param5 = 0.0
+        req.param6 = 0.0
+        req.param7 = 0.0
+        req.timeout_sec = float(timeout_sec)
+
+        future = self._client.call_async(req)
+        rclpy.spin_until_future_complete(self, future, timeout_sec=timeout_sec + 1.0)
+        if not future.done() or future.result() is None:
+            return ChangeModeResult(
+                success=False,
+                message="Service call timeout or no response.",
+                ack_result=-1,
+            )
+
+        response = future.result()
+        return ChangeModeResult(
+            success=response.success,
+            message=response.message,
+            ack_result=response.ack_result,
+        )
+
+
+def change_mode(
+    *,
+    target_sysid: int,
+    custom_mode: float,
+    target_compid: int = 0,
+    base_mode: float = 1.0,
+    confirmation: int = 0,
+    timeout_sec: float = DEFAULT_TIMEOUT_SEC,
+    service_name: str = DEFAULT_SERVICE_NAME,
+) -> ChangeModeResult:
+    """One-shot helper for collaborators who want minimal code."""
+    rclpy.init(args=None)
+    node: Optional[ChangeModeClient] = None
+    try:
+        node = ChangeModeClient(service_name=service_name)
+        if not node.wait_for_service(timeout_sec=timeout_sec):
+            return ChangeModeResult(
+                success=False,
+                message=f"Service not available: {service_name}",
+                ack_result=-1,
+            )
+        return node.change_mode(
+            target_sysid=target_sysid,
+            target_compid=target_compid,
+            custom_mode=custom_mode,
+            base_mode=base_mode,
+            confirmation=confirmation,
+            timeout_sec=timeout_sec,
+        )
+    finally:
+        if node is not None:
+            node.destroy_node()
+        rclpy.shutdown()
+
+
+if __name__ == "__main__":
+    # Example values are aligned with your terminal command.
+    result = change_mode(target_sysid=3, custom_mode=4)
+    print(
+        f"change_mode success={result.success}, "
+        f"ack_result={result.ack_result}, message='{result.message}'"
+    )