[PIC] lcd programming interface with pic18f4550

[deepum]

in LCD interfacing with pic18f4550 microcontroller how to do changes in program when 4 bit data lines (c18 compiler) used. pls someone assist me..

thanks in advance

 

[embRTS]

For 4 bit Data you have to make Bit Shifting to the Original 8 Data Lines Function,
Basically by the INSTRUCTIONS that are used for sending Data to LCD, are assumed to be sent over 8-Data Lines so when you make a function like

LCD_8data(unsigned char rts)
{
// instructions //
}
now modified for 4 data
LCD_4data(unsigned char rt)
{
// Make BIT shift by 4 bit // /*here*/
// that DATA is to be shifted here //
}

 

[deepum]

can you tel something same with example??

 

[horace1]

can you tel something same with example??

for example

// write a data byte to LCD
int lcdPutchar(int d)
{
//    printf("%c", d);
	LCDstatus.RS=1; 				// Take RS pin high for data
	lcdNibble(d >>4);     		    // Makeup Upper Nibble
	lcdNibble(d);		            // Makeup Lower Nibble
    return 1;
}

where LCDnibble Writes a nibble (4 bits) to the LCD