INTERFACING OF PIC18F4550 TO LCD IN 8-BIT MODE

INTERFACING OF PIC18F4550 TO LCD IN 8-BIT MODE

All LCD have two mode of working:

1.)           For 8-bit mode => Command is (0x38).

2.)           For 4-bit mode => Command is (0x28).

Interfacing of PIC to LCD in 8-Bit mode with Busy mode.

• Busy mode is checked using last data pin of LCD display (D7).
• If D7 is High When en Pin.

  

3 Important Pin of LCD are rs, rw, en.

• rs = Register Select pin is used to Select Command or Data Register.
• rw = Read/Write pin is used to Read or Write Data.
• en = Enable pin is used to latch data into display and to read data from lcd.

rs	0	Command
	1	Data
rw	0	Write
	1	Read
en	1-> 0	Latch data into LCD
	0 -> 1	Latch data out from LCD

PORTD = LCD Data.

STEP1:  1^st Set the Last Bit of PORTD i.e. RD7

STEP2:  rs = 0; To Select Command Register.

STEP3:  rw = 1; To Select Read Mode.

STEP4:  en => High to Low. To Latch data out of LCD

STEP5:  Check for Bit Set D7 and if D7 => 1; go to Step4.

                Or else do nothing.


We have to make 3 important Function.
1.) Command Function to send command to LCD
2.) Data Function to send single data to LCD
3.) Initialize LCD to Work in 8-biit Mode.

MODE                             Explanation
0x38       -    LCD as 16 x 2 line in 8-bit mode
0x28       -    LCD as 16 x 2 line in 4-bit mode.
0x0C      -     Cursor ON, Blinking OFF
0x0E      -     Cursor ON, Blinking ON
0x06       -     Auto increment Cursor
0x80       -     1st line and 1st location of LCD
0xC0      -      2nd line and 1st location

Now rest all you will understand by seeing the Code.

Thank You.

Code: Click for Code

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