Earlier I have used 4-bit and 8-bit LCD libraries in different projects. It was hard to maintain and update. Now they are merged in to one library where the simple logic structure is implemented to select 4-bit or 8-bit LCD library just by modifying only three lines of code.
In the library header file there is line added:
//Uncomment this is LCD 4 bit interface isused
//******************************************
#define LCD_4bit
//******************************************
You can select different LCD modes by commenting and uncommenting this line. Also, don’t forget to select proper ports and pins where LCD is connected:
#define LCD_RS 0 //define MCU pin connected to LCD RS #define LCD_RW 1 //define MCU pin connected to LCD R/W #define LCD_E 2 //define MCU pin connected to LCD E #define LCD_D0 0 //define MCU pin connected to LCD D0 #define LCD_D1 1 //define MCU pin connected to LCD D1 #define LCD_D2 2 //define MCU pin connected to LCD D1 #define LCD_D3 3 //define MCU pin connected to LCD D2 #define LCD_D4 4 //define MCU pin connected to LCD D3 #define LCD_D5 5 //define MCU pin connected to LCD D4 #define LCD_D6 6 //define MCU pin connected to LCD D5 #define LCD_D7 7 //define MCU pin connected to LCD D6 #define LDP PORTD //define MCU port connected to LCD data pins #define LCP PORTD //define MCU port connected to LCD control pins #define LDDR DDRD //define MCU direction register for port connected to LCD data pins #define LCDR DDRD //define MCU direction register for port connected to LCD control pins
In AVR LCD library there also is a couple new functionalities added:
- Predefining 8 custom LCD characters during LCD initialisation;
- LCDprogressBar() function, which has been adapted from AVRLib.
Complete set of AVR LCD functions:
void LCDsendChar(uint8_t); //forms data ready to send to 74HC164 void LCDsendCommand(uint8_t); //forms data ready to send to 74HC164 void LCDinit(void); //Initializes LCD void LCDclr(void); //Clears LCD void LCDhome(void); //LCD cursor home void LCDstring(uint8_t*, uint8_t); //Outputs string to LCD void LCDGotoXY(uint8_t, uint8_t); //Cursor to X Y position void CopyStringtoLCD(const uint8_t*, uint8_t, uint8_t);//copies flash string to LCD at x,y void LCDdefinechar(const uint8_t *,uint8_t);//write char to LCD CGRAM void LCDshiftRight(uint8_t); //shift by n characters Right void LCDshiftLeft(uint8_t); //shift by n characters Left void LCDcursorOn(void); //Underline cursor ON void LCDcursorOnBlink(void); //Underline blinking cursor ON void LCDcursorOFF(void); //Cursor OFF void LCDblank(void); //LCD blank but not cleared void LCDvisible(void); //LCD visible void LCDcursorLeft(uint8_t); //Shift cursor left by n void LCDcursorRight(uint8_t); //shif cursor right by n // displays a horizontal progress bar at the current cursor location void LCDprogressBar(uint8_t progress, uint8_t maxprogress, uint8_t length);
I have added simple demo program which should help to start working with AVR and LCD:
