Inverted position shifting idle logo (#1484)

* Inverted idle logo

Back on white background start-up logo.
Inverted idle logo with random positioning.

* Idle Logo display default true

DISPLAY_IDLE_LOGO true as burn-in screens saver, especially fo the constant heading and line

* Display Brightness added

* SSD1306toMQTT / MQTTtoSSD1306

Additional "onstate" and "brightness" setting and regular display state reporting

Docs - separate Displays section

main/config_SSD1306.h

@@ -59,7 +59,7 @@
 #endif
 
 #ifndef DISPLAY_IDLE_LOGO
-#  define DISPLAY_IDLE_LOGO false // Display the OMG logo when idle
+#  define DISPLAY_IDLE_LOGO true // Display the OMG logo when idle
 #endif
 
 #ifndef DISPLAY_METRIC
@@ -70,6 +70,14 @@
 #  define DISPLAY_FLIP true // Flip display orientation
 #endif
 
+#ifndef DISPLAY_STATE
+#  define DISPLAY_STATE true // set to false if you don't want to use the display
+#endif
+
+#ifndef DISPLAY_BRIGHTNESS
+#  define DISPLAY_BRIGHTNESS 50 // 0-100; 50 % brightness as default
+#endif
+
 /*------------------- DEFAULT DISPLAY GEOMETRY ----------------------*/
 
 #define OLED_TEXT_BUFFER 1000
@@ -91,8 +99,8 @@
 
 /*-------------------DEFINE MQTT TOPIC FOR CONFIG----------------------*/
 
-#define subjectMQTTtoSSD1306set "/commands/MQTTtoSSD1306"
-#define subjectSSD1306toMQTTset "/SSD1306toMQTT"
+#define subjectMQTTtoSSD1306set "/commands/MQTTtoSSD1306/config"
+#define subjectSSD1306toMQTT    "/SSD1306toMQTT"
 
 /*-------------------EXTERNAL FUNCTIONS----------------------*/
 
@@ -138,7 +146,7 @@ class OledSerial : public Stream {
 public:
   OledSerial(int);
   void begin();
-  void drawLogo();
+  void drawLogo(int xshift, int yshift);
   boolean displayPage(displayQueueMessage*);
 
   SSD1306Wire* display;