diff --git a/examples/osd/opentrigger-board/resources/res-rgb.c b/examples/osd/opentrigger-board/resources/res-rgb.c
index 8ff074c68..68e34993d 100644
--- a/examples/osd/opentrigger-board/resources/res-rgb.c
+++ b/examples/osd/opentrigger-board/resources/res-rgb.c
@@ -40,6 +40,7 @@
 
 #include <string.h>
 #include "rest-engine.h"
+#include "generic_resource.h"
 #include "Arduino.h"
 #include "sketch.h"
 
@@ -117,3 +118,32 @@ res_post_put_handler(void *request, void *response, uint8_t *buffer, uint16_t pr
     REST.set_response_status(response, REST.status.BAD_REQUEST);
   }
 }
+
+#pragma GCC diagnostic ignored "-Wwrite-strings"
+GENERIC_RESOURCE
+  ( red
+  , RED_LED
+  , s
+  , 1
+  , color_from_string
+  , color_to_string
+  );
+
+GENERIC_RESOURCE
+  ( green
+  , GREEN_LED
+  , s
+  , 1
+  , color_from_string
+  , color_to_string
+  );
+
+GENERIC_RESOURCE
+  ( blue
+  , BLUE_LED
+  , s
+  , 1
+  , color_from_string
+  , color_to_string
+  );
+#pragma GCC diagnostic pop
diff --git a/examples/osd/opentrigger-board/sketch.h b/examples/osd/opentrigger-board/sketch.h
index 5616a1651..065d302d3 100644
--- a/examples/osd/opentrigger-board/sketch.h
+++ b/examples/osd/opentrigger-board/sketch.h
@@ -2,8 +2,15 @@
 #define __SKETCH_h__
 
 #ifdef __cplusplus
-extern "C" 
+extern "C" {
 #endif
+
+size_t color_to_string (const char *name, const char *uri, char *buf, size_t bsize);
+int color_from_string (const char *name, const char *uri, const char *s);
 int color_rgb_from_string (const char *r, const char *g, const char *b);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/examples/osd/opentrigger-board/sketch.pde b/examples/osd/opentrigger-board/sketch.pde
index a4b1d3767..d6bb0c754 100755
--- a/examples/osd/opentrigger-board/sketch.pde
+++ b/examples/osd/opentrigger-board/sketch.pde
@@ -18,12 +18,16 @@ extern "C" {
 #include "net/netstack.h"
 #include "dev/button-sensor.h"
 #include "ChainableLED.h"
+#include "sketch.h"
 }
 
 extern resource_t 
     res_led,
     res_bled,
     res_rgb, 
+    res_red, 
+    res_green, 
+    res_blue, 
     res_battery, 
     res_cputemp,
     res_event,
@@ -63,13 +67,13 @@ name_to_offset (const char * name)
   return offset;
 }
 
-static size_t
+extern "C" size_t
 color_to_string (const char *name, const char *uri, char *buf, size_t bsize)
 {
   return snprintf (buf, bsize, "%d", color_rgb [name_to_offset (name)]);
 }
 
-int 
+extern "C" int 
 color_from_string (const char *name, const char *uri, const char *s)
 {
     color_rgb [name_to_offset (name)] = atoi (s);
@@ -87,34 +91,6 @@ color_rgb_from_string (const char *r, const char *g, const char *b)
     return 0;
 }
 
-#pragma GCC diagnostic ignored "-Wwrite-strings"
-GENERIC_RESOURCE
-  ( red
-  , RED_LED
-  , s
-  , 1
-  , color_from_string
-  , color_to_string
-  );
-
-GENERIC_RESOURCE
-  ( green
-  , GREEN_LED
-  , s
-  , 1
-  , color_from_string
-  , color_to_string
-  );
-
-GENERIC_RESOURCE
-  ( blue
-  , BLUE_LED
-  , s
-  , 1
-  , color_from_string
-  , color_to_string
-  );
-#pragma GCC diagnostic pop
 
 void setup (void)
 {