Fixes #1800: suppress center beep for non-existing pots

radio/src/mixer.cpp

@@ -495,7 +495,9 @@ void evalInputs(uint8_t mode)
         if (tmp==0 || (tmp==1 && (bpanaCenter & mask))) {
           anaCenter |= mask;
           if ((g_model.beepANACenter & mask) && !(bpanaCenter & mask) && !calibrationState) {
-            AUDIO_POT_MIDDLE(i);
+            if (!IS_POT(i) || IS_POT_AVAILABLE(i)) {
+              AUDIO_POT_MIDDLE(i);
+            }
           }
         }
       }

radio/src/opentx.h

@@ -380,6 +380,8 @@ enum PotType {
   #define IS_POT_WITHOUT_DETENT(x)  (true)
 #endif
 
+#define IS_POT(x)                   ((x)>=POT1 && (x)<=POT_LAST)
+
 #define GET_LOWRES_POT_POSITION(i)  (getValue(MIXSRC_FIRST_POT+(i)) >> 4)
 #define SAVE_POT_POSITION(i)        g_model.potPosition[i] = GET_LOWRES_POT_POSITION(i)