From b7dfd9ae61409319c3214e08aa6e529845d4a2e2 Mon Sep 17 00:00:00 2001
From: GuillaumeLaine <guillaume.william1@hotmail.com>
Date: Wed, 5 Feb 2025 18:35:47 +0100
Subject: [PATCH] update readme, revert disabling message compat

---
 README.md                                     | 28 +++++++++++++++++--
 .../include/px4_ros2/components/mode.hpp      |  7 ++---
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index 5782a820..fbd3343d 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # PX4 ROS 2 Interface Library
 
 Library to interface with PX4 from a companion computer using ROS 2.
-It provides some tooling to used to write external modes that are dynamically registered with PX4 and behave the same way as internal ones.
+It provides some tooling used to write external modes that are dynamically registered with PX4 and behave the same way as internal ones.
 A mode can send different types of setpoints, ranging from high-level navigation tasks all the way down to direct actuator controls.
 
 Documentation:
@@ -10,7 +10,12 @@ Documentation:
 
 ## Compatibility with PX4
 The library interacts with PX4 by using its uORB messages, and thus requires a matching set of message definitions on the ROS 2 side.
-Compatibility is only guaranteed if using latest `main` on the PX4 and px4_ros2/px4_msgs side. This might change in the future.
+To ensure compatibility, you must either:
+
+1. Use latest `main` on the PX4 and px4_ros2/px4_msgs sides, which should define matching messages
+1. (Experimental) Run the PX4 [message translation node](https://github.com/PX4/PX4-Autopilot/tree/message_versioning_and_translation/msg/translation_node), which dynamically monitors and translates PX4 messages when different message version are used within the same ROS 2 domain
+
+### Option 1: Match Messages
 
 The library checks for message compatibility on startup when registering a mode.
 `ALL_PX4_ROS2_MESSAGES` defines the set of checked messages. If you use other messages, you can check them using:
@@ -26,6 +31,25 @@ To manually verify that two local versions of PX4 and px4_msgs have matching mes
 ./scripts/check-message-compatibility.py -v path/to/px4_msgs/ path/to/PX4-Autopilot/
 ```
 
+### Option 2: Translate Messages
+
+If you intend to run the message translation node to use mismatching message versions in PX4 and px4_ros2/px4_msgs, then you must manually disable the message compatibility check that runs when registering a mode.
+This can be done the following way:
+
+```c++
+class CustomMode : public px4_ros2::ModeBase
+{
+public:
+  CustomMode(rclcpp::Node & node)
+  : ModeBase(node, "node_name")
+  {
+    setSkipMessageCompatibilityCheck();  // Disables compatibility check
+    ...
+  }
+  ...
+};
+```
+
 ## Examples
 There are code examples under [examples/cpp/modes](examples/cpp/modes).
 
diff --git a/px4_ros2_cpp/include/px4_ros2/components/mode.hpp b/px4_ros2_cpp/include/px4_ros2/components/mode.hpp
index 5177bd94..6f6ca419 100644
--- a/px4_ros2_cpp/include/px4_ros2/components/mode.hpp
+++ b/px4_ros2_cpp/include/px4_ros2/components/mode.hpp
@@ -162,10 +162,7 @@ class ModeBase : public Context
   RequirementFlags & modeRequirements() {return _health_and_arming_checks.modeRequirements();}
 
 protected:
-  void setSkipMessageCompatibilityCheck(bool skip = true)
-  {
-    _skip_message_compatibility_check = skip;
-  }
+  void setSkipMessageCompatibilityCheck() {_skip_message_compatibility_check = true;}
   void overrideRegistration(const std::shared_ptr<Registration> & registration);
 
 private:
@@ -194,7 +191,7 @@ class ModeBase : public Context
   std::shared_ptr<Registration> _registration;
 
   const Settings _settings;
-  bool _skip_message_compatibility_check{true};
+  bool _skip_message_compatibility_check{false};
 
   HealthAndArmingChecks _health_and_arming_checks;