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LCD display on PICDEM 2 Plus board

christinescoms

New Member
I am brand new to Microchip controllers but have extensive experience with Motorola, especially the cpu32Kline.

Have a PICDEM 2 Plus board with a 18F452 that I can make do what I want with the exception of the LCD. It is in 4-bit data mode RD0-RD3 and control bits on RA lcd screen supplier 1,2 and 3 for E, R/W, and RS respectively.

I am using the following lines of code. Any suggestions?




DEFINE OSC 4

DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTA
DEFINE LCD_RSBIT 3
DEFINE LCD_EREG PORTA
DEFINE LCD_EBIT 1
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2

TRISA = $00
TRISD = $00
PORTA.2 = 0
PAUSE 1000

LOOP:
LCDOUT $FE, 1
PAUSE 100
LCDOUT $FE, $0F
PAUSE 100
LCDOUT $FE, $80
PAUSE 100
LCDOUT "Hello"
PAUSE 100

GOTO LOOP


Thanks,
 
Last edited:

sagor1

Active Member
Don't you also need to define the R/W port and bit?

LCD_RWREG - defines the port where R/W line is connected to (set to 0 if not used; 0 is default)
LCD_RWBIT - defines the pin where R/W line is connected to (set to 0 if not used; 0 is default)
 

Pommie

Well-Known Member
Most Helpful Member
You appear to be using a basic compiler, which one?

Your initialisation code is wrong, this is what I use (in C),
Code:
    RW=0;
    E=0;                            //clear enable
    RS = 0;                         //going to write command
    __delay_ms(30);                 //delay for LCD to initialize.
    writeNibble(0x3);              //Required for initialization
    __delay_ms(5);                  //required delay
    writeNibble(0x3);              //Required for initialization
    __delay_ms(1);                  //required delay
    writeCommand(0x20);             //set to 4 bit interface
    writeCommand(0x2c);             //set to 4 bit interface, 2 line and 5*10 font
    writeCommand(0x01);             //clear display
    writeCommand(0x06);             //move cursor right after write
    writeCommand(0x0C);             //turn on display
    writeCommand(0x01);             //clear display
The delay sequence is defined in the LCD datasheet.
I'm assuming that R/W is grounded.
Also, should DEFINE LCD_BITS 4 be DEFINE LCD_BITS 0 as it's using the lower nibble.

Mike.
 

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