diff --git a/lcd.h b/lcd.h
index 75dd6ba..d9515e0 100644
--- a/lcd.h
+++ b/lcd.h
@@ -37,6 +37,8 @@
  *  first dev-version only for I2C-Connection
  *  at ATMega328P like Arduino Uno
  *
+ *  at GRAPHICMODE lib needs SRAM for display
+ *  DISPLAY-WIDTH * DISPLAY-HEIGHT + 2 bytes
  */
 
 #ifndef LCD_H
@@ -56,10 +58,16 @@
 #include <inttypes.h>
 #include <avr/io.h>
 #include <avr/pgmspace.h>
-#include "i2c.h"
+#include "i2c.h"                            // library for I2C-communication
+                                            // if you want to use other lib for I2C
+                                            // edit i2c_xxx commands in this library
+                                            // i2c_start(), i2c_byte(), i2c_stop()
 
 /* TODO: define displaycontroller */
-#define SH1106	// or SSD1306, check datasheet of your display
+#define SH1106                              // or SSD1306, check datasheet of your display
+
+#define GRAPHICMODE                         // TEXTMODE for only text to display,
+                                            // GRAPHICMODE for text and graphic
 
 #define LCD_I2C_ADDR    0x7A
 
@@ -73,16 +81,29 @@
 #define DISPLAY_HEIGHT	64
 #define DISPLAYSIZE		DISPLAY_WIDTH*DISPLAY_HEIGHT/8
 
-void lcd_init(uint8_t dispAttr);
-void lcd_home(void);
-
 void lcd_command(uint8_t cmd[], uint8_t size);				// transmit command to display
 void lcd_data(uint8_t data[], uint16_t size);				// transmit data to display
-void lcd_gotoxy(uint8_t x, uint8_t y);		// set curser at pos x, y. x means character, y means line (page, refer lcd manual)
-void lcd_clrscr(void);						// clear screen
-void lcd_putc(char c);						// print character on screen
-void lcd_puts(const char* s);				// print string, \n-terminated, from ram on screen
-void lcd_puts_p(const char* progmem_s);		// print string from flash on screen
+void lcd_init(uint8_t dispAttr);
+void lcd_home(void);                        // set cursor to 0,0
 void lcd_invert(uint8_t invert);			// invert display
 void lcd_set_contrast(uint8_t contrast);	// set contrast for display
+void lcd_puts(const char* s);				// print string, \n-terminated, from ram on screen (TEXTMODE)
+// or buffer (GRAPHICMODE)
+void lcd_puts_p(const char* progmem_s);		// print string from flash on screen (TEXTMODE)
+// or buffer (GRAPHICMODE)
+
+void lcd_clrscr(void);						// clear screen (and buffer at GRFAICMODE)
+void lcd_gotoxy(uint8_t x, uint8_t y);		// set curser at pos x, y. x means character,
+                                            // y means line (page, refer lcd manual)
+void lcd_putc(char c);						// print character on screen at TEXTMODE
+                                            // at GRAPHICMODE print character to buffer
+#if defined GRAPHICMODE
+void lcd_drawPixel(uint8_t x, uint8_t y, uint8_t color);
+void lcd_drawLine(uint8_t x1, uint8_t y1, uint8_t x2, uint8_t y2, uint8_t color);
+void lcd_drawRect(uint8_t px1, uint8_t py1, uint8_t px2, uint8_t py2, uint8_t color);
+void lcd_fillRect(uint8_t px1, uint8_t py1, uint8_t px2, uint8_t py2, uint8_t color);
+void lcd_drawCircle(uint8_t center_x, uint8_t center_y, uint8_t radius, uint8_t color);
+void lcd_fillCircle(uint8_t center_x, uint8_t center_y, uint8_t radius, uint8_t color);
+void lcd_display(void);						// copy buffer to display RAM
+#endif
 #endif /*  LCD_H  */