add set backlight color function

cppsrc/U8g2lib.h

@@ -124,6 +124,9 @@ class U8G2 : public Print
     void setContrast(uint8_t value) {
       u8g2_SetContrast(&u8g2, value); }
 
+    void setBacklightColor(uint32_t value) {
+      u8g2_SetBacklightColor(&u8g2, value); }
+
     void setDisplayRotation(const u8g2_cb_t *u8g2_cb) {
       u8g2_SetDisplayRotation(&u8g2, u8g2_cb); }
 

cppsrc/U8x8lib.h

@@ -247,6 +247,9 @@ class U8X8 : public Print
     void setContrast(uint8_t value) {
       u8x8_SetContrast(&u8x8, value); }
 
+    void setBacklightColor(uint32_t value) {
+      u8x8_SetBacklightColor(&u8x8, value); }
+
     void setInverseFont(uint8_t value) {
       u8x8_SetInverseFont(&u8x8, value); }
 

csrc/u8g2.h

@@ -375,6 +375,7 @@ struct u8g2_struct
 #define u8g2_SetPowerSave(u8g2, is_enable) u8x8_SetPowerSave(u8g2_GetU8x8(u8g2), (is_enable))
 #define u8g2_SetFlipMode(u8g2, mode) u8x8_SetFlipMode(u8g2_GetU8x8(u8g2), (mode))
 #define u8g2_SetContrast(u8g2, value) u8x8_SetContrast(u8g2_GetU8x8(u8g2), (value))
+#define u8g2_SetBacklightColor(u8g2, value) u8x8_SetBacklightColor(u8g2_GetU8x8(u8g2), (value))
 //#define u8g2_ClearDisplay(u8g2) u8x8_ClearDisplay(u8g2_GetU8x8(u8g2))  obsolete, can not be used in all cases
 void u8g2_ClearDisplay(u8g2_t *u8g2);
 

csrc/u8x8.h

@@ -43,6 +43,7 @@
     U8X8_MSG_DISPLAY_SET_FLIP_MODE
     U8X8_MSG_DISPLAY_SET_POWER_SAVE
     U8X8_MSG_DISPLAY_SET_CONTRAST
+    U8X8_MSG_DISPLAY_SET_BACKLIGHT_COLOR
     U8X8_MSG_DISPLAY_DRAW_TILE
 
   A display driver may decided to breakdown these messages to a lower level interface or
@@ -91,6 +92,9 @@
 /* Undefine this to remove u8x8_SetContrast function */
 #define U8X8_WITH_SET_CONTRAST
 
+/* Undefine this to remove u8x8_SetBacklightColor function */
+#define U8X8_WITH_SET_BACKLIGHT_COLOR
+
 /* Define this for an additional user pointer inside the u8x8 data struct */
 //#define U8X8_WITH_USER_PTR
 
@@ -471,6 +475,15 @@ void u8x8_d_helper_display_init(u8x8_t *u8g2);
 /*  arg_int: 0..255 contrast value */
 #define U8X8_MSG_DISPLAY_SET_CONTRAST 14
 
+/*
+  Name: 	U8X8_MSG_DISPLAY_SET_BACKLIGHT_COLOR
+  Args:	arg_ptr: color: 24-bit RGB
+  Tasks:
+    Set the color of the backlight. The dsplay driver might transform the given
+    24-bit RGB color into the more limited color space of the backlight.
+ */
+#define U8X8_MSG_DISPLAY_SET_BACKLIGHT_COLOR 15
+
 /*
   Name: 	U8X8_MSG_DISPLAY_DRAW_TILE
   Args:	
@@ -498,7 +511,7 @@ void u8x8_d_helper_display_init(u8x8_t *u8g2);
     ABABAB. Totally, cnt*arg_int tiles will be drawn. 
 
 */
-#define U8X8_MSG_DISPLAY_DRAW_TILE 15
+#define U8X8_MSG_DISPLAY_DRAW_TILE 16
 
 
 /*
@@ -515,7 +528,7 @@ void u8x8_d_helper_display_init(u8x8_t *u8g2);
     void u8x8_RefreshDisplay(u8x8_t *u8x8)
   to send the message to the display handler.
 */
-#define U8X8_MSG_DISPLAY_REFRESH 16
+#define U8X8_MSG_DISPLAY_REFRESH 17
 
 /*==========================================*/
 /* u8x8_setup.c */
@@ -555,6 +568,7 @@ void u8x8_InitDisplay(u8x8_t *u8x8);
 void u8x8_SetPowerSave(u8x8_t *u8x8, uint8_t is_enable);
 void u8x8_SetFlipMode(u8x8_t *u8x8, uint8_t mode);
 void u8x8_SetContrast(u8x8_t *u8x8, uint8_t value);
+void u8x8_SetBacklightColor(u8x8_t *u8x8, uint32_t color);
 void u8x8_ClearDisplayWithTile(u8x8_t *u8x8, const uint8_t *buf)  U8X8_NOINLINE;
 void u8x8_ClearDisplay(u8x8_t *u8x8);	// this does not work for u8g2 in some cases
 void u8x8_FillDisplay(u8x8_t *u8x8);

csrc/u8x8_d_e3keys.c

@@ -63,6 +63,7 @@ static const u8x8_display_info_t u8x8_e3keys_sb6432_display_info =
 
 
 #define E3KEYS_AT_CMD_SET_DISPLAY_ADDR_WRITE_DATA 0x40
+#define E3KEYS_AT_CMD_SET_RGB_COLOR 0x42
 #define E3KEYS_AT_CMD_END_TRANSMISSION 0x43
 
 #define E3KEYS_AT_EXT_CMD_START 0x47
@@ -105,6 +106,10 @@ static const uint8_t u8x8_d_e3keys_sb6432_powersave1_seq[] = {
 
 uint8_t u8x8_d_e3keys_sb6432(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr)
 {
+#ifdef U8X8_WITH_SET_BACKLIGHT_COLOR
+  uint32_t color;
+  uint8_t color_bytes[3];
+#endif
   const u8x8_display_info_t *d_info = u8x8->display_info;
   u8x8_tile_t *tile;
   const uint16_t y_addr_offset = d_info->pixel_height / 8;
@@ -124,6 +129,26 @@ uint8_t u8x8_d_e3keys_sb6432(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *a
       else
         u8x8_cad_SendSequence(u8x8, u8x8_d_e3keys_sb6432_powersave0_seq);
       break;
+#ifdef U8X8_WITH_SET_BACKLIGHT_COLOR
+    case U8X8_MSG_DISPLAY_SET_BACKLIGHT_COLOR:
+      color = *((uint32_t *) arg_ptr);
+      /*
+       * Set RGB Color command data layout:
+       * Red:   0 D_6 D_5 D_4 D_3 D_2 D_1 D_0
+       * Green: 0 D_6 D_5 D_4 D_3 D_2 D_1 D_0
+       * Blue:  0 D_6 D_5 D_4 D_3 D_2 D_1 D_0
+       */
+      color_bytes[0] = (color >> 16) & 0x7f; /* red */
+      color_bytes[1] = (color >> 8) & 0x7f; /* green */
+      color_bytes[2] = color & 0x7f; /* blue */
+
+      u8x8_cad_StartTransfer(u8x8);
+      u8x8_cad_SendCmd(u8x8, E3KEYS_AT_CMD_SET_RGB_COLOR);
+      u8x8_cad_SendData(u8x8, 3, color_bytes);
+      u8x8_cad_SendCmd(u8x8, E3KEYS_AT_CMD_END_TRANSMISSION);
+      u8x8_cad_EndTransfer(u8x8);
+      break;
+#endif
     case U8X8_MSG_DISPLAY_DRAW_TILE:
       tile = (u8x8_tile_t *)arg_ptr;
 

csrc/u8x8_display.c

@@ -115,6 +115,11 @@ void u8x8_SetContrast(u8x8_t *u8x8, uint8_t value)
   u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_SET_CONTRAST, value, NULL);  
 }
 
+void u8x8_SetBacklightColor(u8x8_t *u8x8, uint32_t color)
+{
+  u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_SET_BACKLIGHT_COLOR, 0, &color);
+}
+
 void u8x8_RefreshDisplay(u8x8_t *u8x8)
 {
   u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_REFRESH, 0, NULL);  
@@ -162,4 +167,4 @@ void u8x8_ClearLine(u8x8_t *u8x8, uint8_t line)
     tile.tile_ptr = (uint8_t *)buf;		/* tile_ptr should be const, but isn't */
     u8x8->display_cb(u8x8, U8X8_MSG_DISPLAY_DRAW_TILE, u8x8->display_info->tile_width, (void *)&tile);
   }  
-}
+}