Update lcd.h

lcd.h

@@ -61,7 +61,7 @@
 #define TEXTMODE				// TEXTMODE for only text to display,
 						// GRAPHICMODE for text and graphic
 /* TODO: define font */
-#define FONT			ssd1306oled_font
+#define FONT			ssd1306oled_font// set font here, refer font-name at font.h/font.c
 
 /* TODO: define I2C-adress for display */
 
@@ -94,6 +94,7 @@ void lcd_data(uint8_t data[], uint16_t size);				// transmit data to display
 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_sleep(uint8_t sleep);			// display goto sleep (power off)
 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)