Fix black background

lib/obp60task/OBP60Extensions.h

@@ -105,8 +105,8 @@ public:
       cfg.pin_busy = -1;
       cfg.panel_width  = 320;       // Native width resolution
       cfg.panel_height = 480;       // Native hight resolution
-      cfg.offset_x     = 10;        // Display output 400x300 pix to housing center adjusted 
+      cfg.offset_x     = 0;         // No panel offset: full framebuffer mapping
-      cfg.offset_y     = -20;       // Display output 400x300 pix to housing center adjusted
+      cfg.offset_y     = 0;         // No panel offset: full framebuffer mapping
       cfg.offset_rotation = 3;      // Rotate display content conter clock wise 90 deg
       cfg.dummy_read_pixel = 8;
       cfg.dummy_read_bits  = 1;
@@ -260,6 +260,20 @@ public:
   // E-Ink interface compatibility
   void setFullWindow() { /* no-op on TFT */ }
 
+    // Runtime panel offset control (ST7796)
+    void setPanelOffset(int16_t x, int16_t y) {
+            auto cfg = _panel_instance.config();
+            cfg.offset_x = x;
+            cfg.offset_y = y;
+            _panel_instance.config(cfg);
+    }
+
+    void getPanelOffset(int16_t &x, int16_t &y) {
+            auto cfg = _panel_instance.config();
+            x = cfg.offset_x;
+            y = cfg.offset_y;
+    }
+
 private:
     lgfx::GFXfont _adfFontBridge { nullptr, nullptr, 0, 0, 0 };
     lgfx::GFXglyph* _adfGlyphBridge = nullptr;
@@ -494,7 +508,7 @@ inline void displayFirstPage() {
 inline void displayNextPage() {
     #ifdef DISPLAY_ST7796
     if (initDisplayShadowBuffer()) {
-        getdisplay().pushSprite(0, 0);
+        getdisplay().pushSprite((480 - GxEPD_WIDTH) / 2, (320 - GxEPD_HEIGHT) / 2);
     }
     #else
     getdisplay().nextPage();

lib/obp60task/OBP60Hardware.h

@@ -41,6 +41,8 @@
     #define OBP_SPI_BUSY 42
     #define OBP_SPI_CLK 38
     #define OBP_SPI_DIN 48
+    #define OBP_TFT_OFFSET_X 10   // ST7796 operating x-offset for centered 400x300 content
+    #define OBP_TFT_OFFSET_Y -20  // ST7796 operating y-offset for centered 400x300 content
     #define SHOW_TIME 6000        // Show time in [ms] for logo and WiFi QR code
     #define FULL_REFRESH_TIME 600 // Refresh cycle time in [s][600...3600] for full display update (very important healcy function)
     #define GxEPD_WIDTH 400       // Display width

lib/obp60task/obp60task.cpp

@@ -391,7 +391,9 @@ void OBP60Task(GwApi *api){
 
     #ifdef DISPLAY_ST7796
     getpaneldisplay().setRotation(0);            // Set display orientation (horizontal)
+    getpaneldisplay().setPanelOffset(0, 0);      // Use full native framebuffer coordinates
     getpaneldisplay().fillScreen(0x0000);        // Initialize full TFT screen to black (native RGB565)
+    getpaneldisplay().setPanelOffset(OBP_TFT_OFFSET_X, OBP_TFT_OFFSET_Y); // Restore centered 400x300 operating offset
     #else
     getdisplay().setRotation(0);                 // Set display orientation (horizontal)
     #endif