ucglib doc

README.md

@@ -470,6 +470,61 @@ In contrast to the source code based inclusion of XBMs into u8glib, it's require
   - [ ] setRGB()
   - [ ] setDefaultMidColor()
 
+####Operate a display with ucglib
+Ucglib is a graphics library with support for color TFT displays.
+
+Ucglib v1.3.3
+
+#####SPI connection
+The HSPI module is used, so certain pins are fixed:
+* HSPI CLK  = GPIO14
+* HSPI MOSI = GPIO13
+* HSPI MISO = GPIO12 (not used)
+
+All other pins can be assigned to any available GPIO:
+* CS
+* D/C
+* RES (optional for some displays)
+
+Also refer to the initialization sequence eg in [GraphicsTest.lua](lua_examples/ucglib/GraphicsRest.lua):
+```lua
+spi.setup(1, spi.MASTER, spi.CPOL_LOW, spi.CPHA_LOW, spi.DATABITS_8, 0)
+```
+
+#####Library usage
+The Lua bindings for this library closely follow ucglib's object oriented C++ API. Based on the ucg class, you create an object for your display type.
+
+ILI9341 via SPI:
+```lua
+cs  = 8 -- GPIO15, pull-down 10k to GND
+dc  = 4 -- GPIO2
+res = 0 -- GPIO16, RES is optional YMMV
+disp = ucg.ili9341_18x240x320_hw_spi(cs, dc, res)
+```
+
+This object provides all of ucglib's methods to control the display.
+Again, refer to [GraphicsTest.lua](lua_examples/ucglib/GraphicsTest.lua) to get an impression how this is achieved with Lua code. Visit the [ucglib homepage](https://github.com/olikraus/ucglib) for technical details.
+
+#####Displays
+To get access to the display constructors, add the desired entries to the display table in [app/include/ucg_config.h](app/include/ucg_config.h):
+```c
+#define UCG_DISPLAY_TABLE                          \
+    UCG_DISPLAY_TABLE_ENTRY(ili9341_18x240x320_hw_spi, ucg_dev_ili9341_18x240x320, ucg_ext_ili9341_18) \
+    UCG_DISPLAY_TABLE_ENTRY(st7735_18x128x160_hw_spi, ucg_dev_st7735_18x128x160, ucg_ext_st7735_18) \
+```
+
+#####Fonts
+ucglib comes with a wide range of fonts for small displays. Since they need to be compiled into the firmware image, you'd need to include them in [app/include/ucg_config.h](app/include/ucg_config.h) and recompile. Simply add the desired fonts to the font table:
+```c
+#define UCG_FONT_TABLE                              \
+    UCG_FONT_TABLE_ENTRY(font_7x13B_tr)             \
+    UCG_FONT_TABLE_ENTRY(font_helvB12_hr)           \
+    UCG_FONT_TABLE_ENTRY(font_helvB18_hr)           \
+    UCG_FONT_TABLE_ENTRY(font_ncenR12_tr)           \
+    UCG_FONT_TABLE_ENTRY(font_ncenR14_hr)
+```
+They'll be available as `ucg.<font_name>` in Lua.
+
 
 ####Control a WS2812 based light strip
 ```lua