4bit LCD on custom pinout ??

[picnoobie]

#define lcd_db4 0x01

Hello,

I'm trying to convert this to Mplab C30 https://www.ccsinfo.com/forum/viewtopic.php?t=28268 ,
I'm having trouble with lcd_read_nibble part.

How can I store multiple pin state in a variable?
I sort of new to this please be kind


thanks.

 

[picnoobie]

delay_us c30

I manage to make it work, but only writing not reading,
I guess that's all I need for now. If any1's able to port
the code from the link I posted above, please share;

Here's what I came up with, might be usefull to some.

/*Thanks to Original Author*/
#include <p24Hxxxx.h>
typedef char		int8;
typedef unsigned char 	uint8;
typedef int		int16;//signed 16bits
typedef unsigned int	uint16;
typedef long		int32;//signed 32bits
typedef unsigned long	uint32;
typedef unsigned char   BYTE;

/* #defines of the data pins and the corresponding tris pins
   MCU specific */
#define LCD_DB7            _LATB10
#define LCD_DB6            _LATB12
#define LCD_DB5            _LATB9
#define LCD_DB4            _LATB11

#define TRIS_DATA_PIN_7    _TRISB10
#define TRIS_DATA_PIN_6    _TRISB12
#define TRIS_DATA_PIN_5    _TRISB9
#define TRIS_DATA_PIN_4    _TRISB11

/* #defines of the control pins and the corresponding tris pins*/
#define LCD_E              _LATB14       /* PORT for E */
#define LCD_RW             _LATB13       /* PORT for RW */
#define LCD_RS             _LATB8        /* PORT for RS */

#define TRIS_E             _TRISB14    /* TRIS for E */
#define TRIS_RW            _TRISB13    /* TRIS for RW */
#define TRIS_RS            _TRISB8     /* TRIS for RS */

//#define USE_RW_PIN   1

// These are the line addresses for most 4x20 LCDs.
#define LCD_LINE_1_ADDRESS 0x00
#define LCD_LINE_2_ADDRESS 0x40
#define LCD_LINE_3_ADDRESS 0x14
#define LCD_LINE_4_ADDRESS 0x54

// These are the line addresses for LCD's which use
// the Hitachi HD66712U controller chip.
/*
#define LCD_LINE_1_ADDRESS 0x00
#define LCD_LINE_2_ADDRESS 0x20
#define LCD_LINE_3_ADDRESS 0x40
#define LCD_LINE_4_ADDRESS 0x60
*/

//========================================

#define lcd_type 2   // 0=5x7, 1=5x10, 2=2 lines(or more)

void lcd_send_nibble(uint8 nibble);
void lcd_send_byte(uint8 address, uint8 n);
void lcd_gotoxy(uint8 x, uint8 y);
void lcd_putc(char c);
void prints(char *str);
void lcd_init();

uint8 lcd_line;

uint8 const LCD_INIT_STRING[4] =
{
 0x20 | (lcd_type << 2),  // Set mode: 4-bit, 2+ lines, 5x8 dots      0x20 | (lcd_type << 2)
 0xc,                     // Display on
 1,                       // Clear display
 6                        // Increment cursor
 };
//-------------------------------------
void lcd_send_nibble(uint8 nibble)
{   
    TRIS_DATA_PIN_7 = 0;
    TRIS_DATA_PIN_6 = 0;
    TRIS_DATA_PIN_5 = 0;
    TRIS_DATA_PIN_4 = 0;

// Note:  !! converts an integer expression
// to a boolean (1 or 0).
 LCD_DB4 = !!(nibble & 1);
 LCD_DB5 = !!(nibble & 2);
 LCD_DB6 = !!(nibble & 4);
 LCD_DB7 = !!(nibble & 8);

 Delay_Us(1);
 LCD_E = 1; //output_high(LCD_E);
 Delay_Us(2);
 LCD_E = 0; //output_low(LCD_E);
}

//----------------------------------------
// Send a byte to the LCD.
void lcd_send_byte(uint8 address, uint8 n)
{

LCD_RS = 0;

Delay_Ms(10);/* can't get the busy flag
                working, this works for now
                */
if(address)
   LCD_RS = 1;
else
   LCD_RS = 0;

Delay_Us(1);
LCD_RW = 0;
Delay_Us(1);
LCD_E = 0;

lcd_send_nibble(n >> 4);
lcd_send_nibble(n & 0xf);
}
//----------------------------

void lcd_init(void)
{
uint8 i;
lcd_line = 1;

	TRIS_DATA_PIN_7 = 0;
    	TRIS_DATA_PIN_6 = 0;
    	TRIS_DATA_PIN_5 = 0;
    	TRIS_DATA_PIN_4 = 0;
    	TRIS_E = 0;
	TRIS_RW = 0;
	TRIS_RS = 0;

     //TRISB = 0;

LCD_RS  = 0;
LCD_RW = 0;
LCD_E = 0;
// Some LCDs require 15 ms minimum delay after
// power-up.  Others require 30 ms.  I'm going
// to set it to 35 ms, so it should work with
// all of them.
Delay_Ms(35);

for(i=0 ;i < 3; i++)
   {
    lcd_send_nibble(0x03);
    Delay_Ms(5);
   }
 
lcd_send_nibble(0x02);
//lcd_send_nibble(0x28);
//lcd_send_nibble(0x0C);
//lcd_send_nibble(0x06);
//lcd_send_nibble(0x01);


for(i=0; i < sizeof(LCD_INIT_STRING); i++)
   {
   	 lcd_send_byte(0, LCD_INIT_STRING[i]);

   }

}

//----------------------------

void lcd_gotoxy(uint8 x, uint8 y)
{
uint8 address;


switch(y)
  {
   case 1:
     address = LCD_LINE_1_ADDRESS;
     break;

   case 2:
     address = LCD_LINE_2_ADDRESS;
     break;

   case 3:
     address = LCD_LINE_3_ADDRESS;
     break;

   case 4:
     address = LCD_LINE_4_ADDRESS;
     break;

   default:
     address = LCD_LINE_1_ADDRESS;
     break;
     
  }

address += x-1;
lcd_send_byte(0, 0x80 | address);
}

//-----------------------------
void lcd_putc(char c)
{
 switch(c)
   {
    case '\f':
      lcd_send_byte(0,1);
      lcd_line = 1;
      Delay_Ms(2);
      break;
   
    case '\n':
       lcd_gotoxy(1, ++lcd_line);
       break;
   
    case '\b':
       lcd_send_byte(0,0x10);
       break;
   
    default:
       lcd_send_byte(1,c);
       break;
   }
}

void prints(char *str)
{
  uint8 i;

  i = 0;
  while (str[i]) {
    lcd_putc(str[i++]);
  }
}

 

[ravikumar001]

Re: LCD asm code pic

hi

see this asm code at romux

MAIN        
            MOVLW  .23 
            MOVWF   TEMP        ;Put any value   to variable  temp ; for printing on LCD        
                    
            LCDINIT                ;Incitializing LCD        
LOOP        
            LCDCMD 0X01            ;Clear  LCD
            LCDTEXT 1,"   ROMUX   ";Print text from line  1,   char  1 
            LCDTEXT 2,"PROBA LCD";Print text from line  2,   char  1 
            PAUSEMS .2000         ;2  sec pause  
            LCDCMD 0X01            ;Clear  LCD   
            LCDTEXT 1,"TEMPERATURE" ;Print text from line  1,   char  1 
            LCDTEXT 2,"TEMP="    ;Print text from line  2,   char  1 
            LCDBYTE TEMP        ;Print decimal value  of variable
            LCDTEXT 0,"C"        ;Print text from the  current 
            PAUSEMS    .2000          ;cursor position
                                               
              GOTO  LOOP                
            END