* refactored buzzer concept to UITask

* moved buzzer.h/cpp to helpers/ui

src/helpers/ui/buzzer.h

@@ -0,0 +1,36 @@
+#pragma once
+
+#include <Arduino.h>
+#include <NonBlockingRtttl.h>
+
+/* class abstracts underlying RTTTL library 
+
+    Just a simple imlementation to start.  At the moment use same
+    melody for message and discovery
+    Suggest enum type for different sounds
+    - on message
+    - on discovery
+
+    TODO
+    - make message ring tone configurable
+
+*/
+class genericBuzzer
+{
+    public:
+        void begin();  // set up buzzer port
+        void play(const char *melody); // Generic play function
+        void loop();  // loop driven-nonblocking
+        void startup();  // play startup sound
+        void shutdown();  // play shutdown sound
+        bool isPlaying();  // returns true if a sound is still playing else false
+        void quiet(bool buzzer_state);  // enables or disables the buzzer
+        bool isQuiet();  // get buzzer state on/off
+
+    private:
+        // gemini's picks:
+        const char *startup_song = "Startup:d=4,o=5,b=160:16c6,16e6,8g6";
+        const char *shutdown_song = "Shutdown:d=4,o=5,b=100:8g5,16e5,16c5";
+
+        bool _is_quiet = true;
+};