this kinda works

simconnect-sdk/build.rs

@@ -32,6 +32,7 @@ fn main() {
         .allowlist_function("SimConnect_Open")
         .allowlist_function("SimConnect_RemoveClientEvent")
         .allowlist_function("SimConnect_RequestDataOnSimObject")
+        .allowlist_function("SimConnect_SetDataOnSimObject")
         .allowlist_function("SimConnect_RequestFacilitiesList")
         .allowlist_function("SimConnect_SetNotificationGroupPriority")
         .allowlist_function("SimConnect_SubscribeToFacilities")

simconnect-sdk/src/simconnect/objects.rs

@@ -109,4 +109,47 @@ impl SimConnect {
             )
         })
     }
+
+    pub fn set_data_on_sim_object<T>(&self, obj: &mut T) -> Result<(), SimConnectError> {
+        let type_name: String = std::any::type_name::<T>().into();
+
+        let request_id = self
+            .registered_objects
+            .get(&type_name)
+            .ok_or_else(|| SimConnectError::ObjectNotRegistered(type_name.clone()))?;
+
+        success!(unsafe {
+            bindings::SimConnect_SetDataOnSimObject(
+                self.handle.as_ptr(),
+                request_id.id,
+                bindings::SIMCONNECT_OBJECT_ID_USER,
+                Condition::None.into(),
+                0,
+                size_of::<T>().try_into().unwrap(),
+                obj as *mut _ as *mut std::ffi::c_void,
+            )
+        })
+    }
+
+    pub fn set_data_on_sim_object_with_id<T>(
+        &self,
+        request_id: u32,
+        obj: &mut T,
+    ) -> Result<(), SimConnectError> {
+        // Strings require to be something specific, so until we can figure out how to
+        // convert the strings "on-the-fly"
+        // we'll use the packed variant of the struct, but it'll need a custom request_id
+
+        success!(unsafe {
+            bindings::SimConnect_SetDataOnSimObject(
+                self.handle.as_ptr(),
+                request_id,
+                bindings::SIMCONNECT_OBJECT_ID_USER,
+                Condition::None.into(),
+                0,
+                size_of::<T>().try_into().unwrap(),
+                obj as *mut _ as *mut std::ffi::c_void,
+            )
+        })
+    }
 }