* these functions must be implemented for a concrete hardware
*/
-void hal_lcd_set_pixel(unsigned int x, unsigned int y, unsigned char state);
+void hal_lcd_set_pixel(uint8_t x, uint8_t y, uint8_t color);
void hal_lcd_clear_display(void);
void hal_lcd_update_display(void);
/* sets the backlight on/off, on=TRUE, off=FALSE */