Mark startRequest and stopRequest as volatile for cross-task visibility

src/PiepPattern.h

@@ -28,7 +28,7 @@ private :
 	uint8_t counter;
 	uint8_t modeIndex;
 	uint8_t outPin;
-	uint8_t startRequest, stopRequest;
+	volatile uint8_t startRequest, stopRequest; /* written by loop task, read by beepTask */
 	uint8_t state;
 
 };