AP_Param: added a method for example programs to set parameters in objects

libraries/AP_Param/AP_Param.cpp

@@ -819,6 +819,24 @@ void AP_Param::setup_object_defaults(const void *object_pointer, const struct Gr
     }
 }
 
+// set a value directly in an object. This should only be used by
+// example code, not by mainline vehicle code
+void AP_Param::set_object_value(const void *object_pointer, 
+                                const struct GroupInfo *group_info, 
+                                const char *name, float value)
+{
+    uintptr_t base = (uintptr_t)object_pointer;
+    uint8_t type;
+    for (uint8_t i=0;
+         (type=PGM_UINT8(&group_info[i].type)) != AP_PARAM_NONE;
+         i++) {
+        if (strcmp(name, group_info[i].name) == 0 && type <= AP_PARAM_FLOAT) {
+            void *ptr = (void *)(base + PGM_UINT16(&group_info[i].offset));
+            set_value((enum ap_var_type)type, ptr, value);
+        }
+    }
+}
+
 
 // load default values for all scalars in a sketch. This does not
 // recurse into sub-objects

libraries/AP_Param/AP_Param.h

@@ -199,6 +199,12 @@ public:
     // load default values for scalars in a group
     static void         setup_object_defaults(const void *object_pointer, const struct GroupInfo *group_info);
 
+    // set a value directly in an object. This should only be used by
+    // example code, not by mainline vehicle code
+    static void set_object_value(const void *object_pointer, 
+                                 const struct GroupInfo *group_info, 
+                                 const char *name, float value);
+
     // load default values for all scalars in the main sketch. This
     // does not recurse into the sub-objects    
     static void         setup_sketch_defaults(void);