diff --git a/Transceiver52M/radioInterface.h b/Transceiver52M/radioInterface.h
index 877102f..b359cbd 100644
--- a/Transceiver52M/radioInterface.h
+++ b/Transceiver52M/radioInterface.h
@@ -78,7 +78,8 @@
 public:
 
   /** start the interface */
-  void start();
+  bool start();
+  bool stop();
 
   /** intialization */
   virtual bool init(int type);