diff --git a/README.md b/README.md
index a21378c4..46066c9f 100644
--- a/README.md
+++ b/README.md
@@ -360,8 +360,27 @@ cu:send("hello")
 ```
 
 ####Operate a display with u8glib
-u8glib is a graphics library with support for many different displays.
-The integration in nodemcu is developed for SSD1306 based display attached via the I2C port. Further display types and SPI connectivity will be added in the future.
+u8glib is a graphics library with support for many different displays. The nodemcu firmware supports a subset of these.
+Both I2C and SPI:
+* sh1106_128x64
+* ssd1306 - 128x64 and 64x48 variants
+* ssd1309_128x64
+* ssd1327_96x96_gr
+* uc1611 - dogm240 and dogxl240 variants
+
+SPI only:
+* ld7032_60x32
+* pcd8544_84x48
+* pcf8812_96x65
+* ssd1322_nhd31oled - bw and gr variants
+* ssd1325_nhd27oled - bw and gr variants
+* ssd1351_128x128 - gh and hicolor variants
+* st7565_64128n - variants 64128n, dogm128/132, lm6059/lm6063, c12832/c12864
+* uc1601_c128032
+* uc1608 - 240x128 and 240x64 variants
+* uc1610_dogxl160 - bw and gr variants
+* uc1611 - dogm240 and dogxl240 variants
+* uc1701 - dogs102 and mini12864 variants
 
 U8glib v1.18.1
 
diff --git a/app/modules/u8g.c b/app/modules/u8g.c
index 24d2062b..7747a9de 100644
--- a/app/modules/u8g.c
+++ b/app/modules/u8g.c
@@ -65,6 +65,8 @@ static int lu8g_setFont( lua_State *L )
     u8g_fntpgm_uint8_t *font = (u8g_fntpgm_uint8_t *)lua_touserdata( L, 2 );
     if (font != NULL)
         u8g_SetFont( LU8G, font );
+    else
+        luaL_argerror(L, 2, "font data expected");
 
     return 0;
 }
@@ -301,32 +303,24 @@ static int lu8g_generic_drawStr( lua_State *L, uint8_t rot )
 // Lua: pix_len = u8g.drawStr( self, x, y, string )
 static int lu8g_drawStr( lua_State *L )
 {
-    lu8g_userdata_t *lud;
-
     return lu8g_generic_drawStr( L, 0 );
 }
 
 // Lua: pix_len = u8g.drawStr90( self, x, y, string )
 static int lu8g_drawStr90( lua_State *L )
 {
-    lu8g_userdata_t *lud;
-
     return lu8g_generic_drawStr( L, 1 );
 }
 
 // Lua: pix_len = u8g.drawStr180( self, x, y, string )
 static int lu8g_drawStr180( lua_State *L )
 {
-    lu8g_userdata_t *lud;
-
     return lu8g_generic_drawStr( L, 2 );
 }
 
 // Lua: pix_len = u8g.drawStr270( self, x, y, string )
 static int lu8g_drawStr270( lua_State *L )
 {
-    lu8g_userdata_t *lud;
-
     return lu8g_generic_drawStr( L, 3 );
 }
 
@@ -1147,13 +1141,14 @@ LUALIB_API int luaopen_u8g( lua_State *L )
 
     // Options for circle/ ellipse drawing
     MOD_REG_NUMBER( L, "DRAW_UPPER_RIGHT", U8G_DRAW_UPPER_RIGHT );
-    MOD_REG_NUMBER( L, "DRAW_UPPER_LEFT",  U8G_DRAW_UPPER_RIGHT );
-    MOD_REG_NUMBER( L, "DRAW_LOWER_RIGHT", U8G_DRAW_UPPER_RIGHT );
-    MOD_REG_NUMBER( L, "DRAW_LOWER_LEFT",  U8G_DRAW_UPPER_RIGHT );
+    MOD_REG_NUMBER( L, "DRAW_UPPER_LEFT",  U8G_DRAW_UPPER_LEFT );
+    MOD_REG_NUMBER( L, "DRAW_LOWER_RIGHT", U8G_DRAW_LOWER_RIGHT );
+    MOD_REG_NUMBER( L, "DRAW_LOWER_LEFT",  U8G_DRAW_LOWER_LEFT );
+    MOD_REG_NUMBER( L, "DRAW_ALL",         U8G_DRAW_ALL );
 
     // Display modes
     MOD_REG_NUMBER( L, "MODE_BW",       U8G_MODE_BW );
-    MOD_REG_NUMBER( L, "MODE_GRAY2BIT", U8G_MODE_BW );
+    MOD_REG_NUMBER( L, "MODE_GRAY2BIT", U8G_MODE_GRAY2BIT );
 
     // create metatable
     luaL_newmetatable(L, "u8g.display");