fix overflow and mute

RingBuffer.h

@@ -13,13 +13,16 @@ public:
         return start == end;
     }
 
-    void push(T element) {
+    bool push(T element) {
+        bool pushed = false;
         noInterrupts();
         if (!isFull()) {
             data[end] = element;
             end = (end + 1) % BufferSize;
+            pushed = true;
         }
         interrupts();
+        return pushed;
     }
 
     T* pop() {