char handling for MQTT messages

src/AWTRIXController.cpp

@@ -75,7 +75,12 @@ byte utf8ascii(byte ascii) {
   switch (last)     // conversion depending on first UTF8-character
   { case 0xC2: return  (ascii) - 34;  break;
     case 0xC3: return  (ascii | 0xC0) - 34;  break;// TomThumb extended characters off by 34
-    case 0x82: if (ascii == 0xAC) return (0xEA);   // special case Euro-symbol
+    case 0x82: if (ascii == 0xAC) return (0xEA);  break;   // special case Euro-symbol
+		case 0xFF: { if (ascii == 0xFF) return (0);            //case area for MQTT charset
+								 if (ascii == 0x80) return (0xEA);				 //MQTT € is send as 0xFFFFFF80
+							   return (ascii) - 34;
+								 break;
+							 }
   }
   return  (0);                                     // otherwise: return zero, if character has to be ignored
 }