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docs/lcd_api.md

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+# LCD API
+
+## Introduction
+
+The LCD API can be used to display BMP images or text onto the LCD screen.
+At the moment of writing, only BMP's in C array's are supported.
+Supported color schemes for BMP's are ARGB8888, RGB565, RGB888.
+Displayed text that is exceeds the LCD width size, will be wrapped onto the next line and a '-' character will be injected if the wrap occurs within a word.
+
+## Usage of LCD API
+### Generating BMP C header files
+#### Resizing images
+To resize an image to the desired size (width and height), one can use an image editor such as Photoshop, GIMP, ImageMagick, ... .
+
+For example, using ImageMagick:
+```bash
+convert in.png -resize 10% BMP3:out.bmp
+#OR (depending on the version of ImageMagick)
+magick in.png -resize 50x50 out.png
+```
+
+The resize option can both be used to resize in percentages or in pixels.
+
+The BMP3 option is used to convert the PNG to Bitmap version 3.0 (note that the BMP header will still be present in the output image).
+
+#### Generating the C array
+To easily generate a BMP C array (in the desired color scheme) from an image, [lv_img_conv](https://github.com/lvgl/lv_img_conv) can be used.
+
+See the installation instructions on Github or use the [online version](https://lvgl.io/tools/imageconverter).
+
+Example:
+```bash
+./lv_img_conv.js test.png -f -c CF_TRUE_COLOR
+```
+
+The command above will generate a .c file in which arrays can be found for RGB332, RGB565, ARGB8888. It is also possible to generate a binary BMP image file in ARGB8332, ARGB8565, ARGB8565_RBSWAP, ARGB8888.
+```bash
+./lv_img_conv.js logo_lvgl.png -f -c CF_TRUE_COLOR -t bin --binary-format ARGB8888
+```
+
+### Using the LCD API
+#### Initialization of LCD API
+The `lcd_init(bool bl_on)` function initialises the LCD screen. The `bl_on` variable allows to enable or disable the LCD backlight.
+```c
+#include "lcd_api.h"
+
+...
+
+void main(void) {
+    ...
+    lcd_init(true);
+    ...
+}
+```
+
+#### Drawing text on the screen
+
+```c
+void lcd_display_text(const char* text, uint16_t x_pos, uint16_t y_pos, uint32_t color, uint32_t bg_color, sFONT *font);
+```
+
+```c
+#include "lcd_api.h"
+
+...
+
+void main(void) {
+    ...
+    lcd_init(true);
+    ...
+    lcd_display_text("This is a text string.", 10, 10, LCD_GREEN, LCD_BLACK, LCD_FONT16);
+}
+```
+Display text on the LCD screen in a certain color. When text width exceeds BSP_LCD_GetXSize(), a text wrap will be performed. If the text wrap is between two will be injected.
+
+#### Drawing a BMP (C-array) onto the screen
+```c
+void lcd_draw_bmp(const void* p_src, uint32_t x_pos, uint32_t y_pos, uint32_t x_size, uint32_t y_size, uint32_t color_mode);
+```
+
+```c
+#include "lcd_api.h"
+#include "test_image.h"
+
+void main(void) {
+  ...
+  lcd_init(true);
+  ...
+  lcd_draw_bmp(bmp_array, 0, 0, 50, 50, LCD_ARGB8888);
+}
+```
+Draw BMP image from C array to the LCD screen at position X, Y. In color mode ARGB8888, RGB888, RGB565 or ARGB1555 Supports ARGB8888, RGB565, RGB888 (see LCD_* defines in header file).