diff --git a/inc/gps.h b/inc/gps.h
--- a/inc/gps.h
+++ b/inc/gps.h
@@ -6,10 +6,10 @@
 
 typedef struct _gps_data
 {
-    int32_t pdop;
-    int32_t sats_in_solution;
-    uint32_t speed;
-    //! int32_t heading;
+    uint32_t pdop;
+    uint8_t sats_in_solution;
+    int32_t speed;
+    int32_t heading;
 
     int32_t latitude;
     int32_t longitude;
@@ -27,7 +27,6 @@ typedef struct _gps_data
 } gps_data_t;
 
 
-void gps_init();
 void gps_update_data(void);
 
 uint8_t gps_check_nav(void);
@@ -40,5 +39,6 @@ void gps_acquirefix(void);
 uint8_t gps_getstate(void);
 
 gps_data_t* gps_getdata(void);
+uint8_t gps_ison(void);
 
 #endif /* GPS_H_ */