Revert backlight to active-high, implement Draw_Sunflower_Pattern boot screen for empty storage states

sound_picture_app/Display_PNG.cpp

@@ -122,3 +122,38 @@ void Draw_Candle_Flicker() {
   
   LCD_addWindow(71, 125, 101, 167, canvas);
 }
+
+void Draw_Sunflower_Pattern() {
+  clearScreen();
+  
+  // Fill the screen with a stylized sunflower:
+  // Center of screen is x=86, y=160.
+  uint16_t line[172];
+  
+  for (int y = 0; y < 320; y++) {
+    for (int x = 0; x < 172; x++) {
+      int dx = x - 86;
+      int dy = y - 160;
+      int dist2 = dx*dx + dy*dy;
+      
+      if (dist2 < 30*30) {
+        // Sunflower center (brown)
+        line[x] = 0x5140; // dark brown
+      } else if (dist2 < 65*65 && (abs(dx) < 15 || abs(dy) < 15 || abs(dx-dy) < 12 || abs(dx+dy) < 12)) {
+        // Golden petals
+        line[x] = 0xFDA0; // Golden orange/yellow
+      } else if (dist2 < 70*70 && (abs(dx) < 22 || abs(dy) < 22)) {
+        // Outer petals highlight
+        line[x] = 0xFFE0; // Yellow
+      } else {
+        // Charcoal background
+        line[x] = 0x18C3; // Very dark warm gray
+      }
+    }
+    // Swap bytes for ST7789 SPI big-endian transfer
+    for (int x = 0; x < 172; x++) {
+      line[x] = __builtin_bswap16(line[x]);
+    }
+    LCD_addWindow(0, y, 171, y, line);
+  }
+}

sound_picture_app/Display_PNG.h

@@ -13,3 +13,4 @@ void Display_Memory_Photo(int memoryIndex);
 // Standby Remembrance Candle Flicker animation
 void Draw_Candle_Body();
 void Draw_Candle_Flicker();
+void Draw_Sunflower_Pattern();

sound_picture_app/Display_ST7789.cpp

@@ -208,15 +208,15 @@ void LCD_addWindow(uint16_t Xstart, uint16_t Ystart, uint16_t Xend, uint16_t Yen
 void Backlight_Init(void)
 {
   pinMode(EXAMPLE_PIN_NUM_BK_LIGHT, OUTPUT);
-  digitalWrite(EXAMPLE_PIN_NUM_BK_LIGHT, LOW); // Set backlight to full brightness (LOW for active-low)
+  digitalWrite(EXAMPLE_PIN_NUM_BK_LIGHT, HIGH); // Set backlight to full brightness (HIGH for active-high)
 }
 
 void Set_Backlight(uint8_t Light)
 {
   pinMode(EXAMPLE_PIN_NUM_BK_LIGHT, OUTPUT);
   if (Light > 0) {
-    digitalWrite(EXAMPLE_PIN_NUM_BK_LIGHT, LOW); // ON (active-low)
+    digitalWrite(EXAMPLE_PIN_NUM_BK_LIGHT, HIGH); // ON (active-high)
   } else {
-    digitalWrite(EXAMPLE_PIN_NUM_BK_LIGHT, HIGH); // OFF
+    digitalWrite(EXAMPLE_PIN_NUM_BK_LIGHT, LOW); // OFF
   }
 }

sound_picture_app/sound_picture_app.ino

@@ -122,7 +122,7 @@ void setup() {
   if (g_memoryCount == 0) {
     printf("No memories found. Add some via the web app.\r\n");
     g_standbyActive = true;
-    Draw_Candle_Body();
+    Draw_Sunflower_Pattern();
   } else {
     int favoriteIndex = -1;
     if (g_favoriteMemoryId >= 0) {
@@ -238,7 +238,7 @@ void loop() {
   if (g_memoryCount == 0) {
     if (!g_standbyActive) {
       g_standbyActive = true;
-      Draw_Candle_Body();
+      Draw_Sunflower_Pattern();
     }
   } else if (!g_standbyActive && !isAudioPlaying() && currentState == STATE_IDLE && !g_tributeActive) {
     if (now - lastInteractionTime > STANDBY_TIMEOUT) {
@@ -248,7 +248,7 @@ void loop() {
     }
   }
 
-  if (g_standbyActive) {
+  if (g_standbyActive && g_memoryCount > 0) {
     Draw_Candle_Flicker();
   }