Index: callback.h
===================================================================
--- callback.h	(revision 624)
+++ callback.h	(revision 625)
@@ -31,4 +31,18 @@
 %%(c) void loop(void) %%
 **/
 
+__rayapi void raydium_set_display_callback(void (*fdisplay));
+/**
+This function will install display callback but don't enter in an infinite loop.
+fdisplay is user display function.
+"fdisplay" must be: 
+%%(c) void fdisplay(void) %%
+**/
+
+__rayapi void raydium_loop(void);
+/**
+Run raydium once. This function needs to be called periodically.
+This function return after loop completion.
+It is usefull to integrate raydium loop in an other program.
+**/
 #endif