LCD driver for custom pins

[adrianrb]

Hello again...

I have a custom development board with a LCD (16x2) attached.
A 16F628 chip is attached to it as follows:

RB0-3 -> LCD Data
RB4 -> LCD Enable
RB5 -> LCD RS
RB6-7 -> unused

I change the default lcd.c to lcd_multipic.c as follows, but
nothing happens. Whtat´s wrong?

Adrian

======= LCD code changed =======

///////////////////////////////////////////////////////////////////////////
//// LCDD.C ////
//// Driver for common LCD modules ////
//// ////
//// lcd_init() Must be called before any other function. ////
//// ////
//// lcd_putc(c) Will display c on the next position of the LCD. ////
//// The following have special meaning: ////
//// \f Clear display ////
//// \n Go to start of second line ////
//// \b Move back one position ////
//// ////
//// lcd_gotoxy(x,y) Set write position on LCD (upper left is 1,1) ////
//// ////
//// lcd_getc(x,y) Returns character at position x,y on LCD ////
//// ////
///////////////////////////////////////////////////////////////////////////
//// (C) Copyright 1996,2003 Custom Computer Services ////
//// This source code may only be used by licensed users of the CCS C ////
//// compiler. This source code may only be distributed to other ////
//// licensed users of the CCS C compiler. No other use, reproduction ////
//// or distribution is permitted without written permission. ////
//// Derivative programs created using this software in object code ////
//// form are not restricted in any way. ////
///////////////////////////////////////////////////////////////////////////

// As defined in the following structure the pin connection is as follows:
// D0 enable
// D1 rs
// D2 rw
// D4 D4
// D5 D5
// D6 D6
// D7 D7
//
// LCD pins D0-D3 are not used and PIC D3 is not used.

// Un-comment the following define to use port B
//#define use_portb_lcd TRUE
#use delay(clock=4000000) // Informa o clock para rotinas de tempo.


struct lcd_pin_map {
int data : 4; // RB0-3 is data nibble
BOOLEAN enable; // RB4 is ENABLE
BOOLEAN rs; // RB5 is RS
BOOLEAN rw; // RB6 is RW
BOOLEAN unused; // RB7 is unused
} lcd;


#if defined(__PCH__)
#if defined use_portb_lcd
#byte lcd = 0xF81 // This puts the entire structure
#else
#byte lcd = 0xF83 // This puts the entire structure
#endif
#else
#if defined use_portb_lcd
#byte lcd = 6 // on to port B (at address 6)
#else
#byte lcd = 8 // on to port D (at address 8)
#endif
#endif

#if defined use_portb_lcd
#define set_tris_lcd(x) set_tris_b(x)
#else
#define set_tris_lcd(x) set_tris_d(x)
#endif


#define lcd_type 2 // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_two 0x40 // LCD RAM address for the second line


BYTE const LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};
// These bytes need to be sent to the LCD
// to start it up.


// The following are used for setting
// the I/O port direction register.

struct lcd_pin_map const LCD_WRITE = {0,0,0,0,0}; // For write mode all pins are out
struct lcd_pin_map const LCD_READ = {15,0,0,0,0}; // For read mode data pins are in

BYTE lcd_read_byte() {
BYTE low,high;
set_tris_lcd(LCD_READ);
lcd.rw = 1;
delay_cycles(1);
lcd.enable = 1;
delay_cycles(1);
high = lcd.data;
lcd.enable = 0;
delay_cycles(1);
lcd.enable = 1;
delay_us(1);
low = lcd.data;
lcd.enable = 0;
set_tris_lcd(LCD_WRITE);
return( (high<<4>> 4);
lcd_send_nibble(n & 0xf);
}


void lcd_init() {
BYTE i;
set_tris_lcd(LCD_WRITE);
lcd.rs = 0;
lcd.rw = 0;
lcd.enable = 0;
delay_ms(15);
for(i=1;i<=3;++i) {
lcd_send_nibble(3);
delay_ms(5);
}
lcd_send_nibble(2);
for(i=0;i<=3;++i)
lcd_send_byte(0,LCD_INIT_STRING[i]);
}


void lcd_gotoxy( BYTE x, BYTE y) {
BYTE address;

if(y!=1)
address=lcd_line_two;
else
address=0;
address+=x-1;
lcd_send_byte(0,0x80|address);
}

void lcd_putc( char c) {
switch (c) {
case '\f' : lcd_send_byte(0,1);
delay_ms(2);
break;
case '\n' : lcd_gotoxy(1,2); break;
case '\b' : lcd_send_byte(0,0x10); break;
default : lcd_send_byte(1,c); break;
}
}

char lcd_getc( BYTE x, BYTE y) {
char value;

lcd_gotoxy(x,y);
while ( bit_test(lcd_read_byte(),7) ); // wait until busy flag is low
lcd.rs=1;
value = lcd_read_byte();
lcd.rs=0;
return(value);
}

======= Test code =======

#include <16F628.h>
#fuses INTRC, NOWDT, NOPROTECT, PUT, NOBROWNOUT, NOLVP, NOMCLR
#use delay(clock=4000000)

#define use_portb_lcd 1
#include "..\lcd_multipic.c"

void main()
{
set_tris_b(0);

lcd_init();
lcd_putc("\fTeste...\n");

for(;;);
}

[Storic]

I used this code "LCDD.c" and worked for me, not straight away, my problem was the contrast.

If you are not using the RW pin why not try

http://www.ccsinfo.com/forum/viewtopic.php?t=28716

Andrew
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