Well, I tried to diagnostic my PIC and LCD module (JHD 162A),
by referring to this page.

I am using the PCWH to compile and get the HEX file.

The main program code:

#include <16F88.h>
#fuses HS,NOWDT,PUT,NOLVP
#use delay(clock=20000000)
#include "flex_lcd.c"
   
//==========================
void main()
{
lcd_init();  // Always call this first.

lcd_putc("\fHello World\n");
lcd_putc("Line Number 2");

while(1);
}

And I modified the flex_lcd.c to meet my PIC:

// flex_lcd.c

// These pins are for the Microchip PicDem2-Plus board,
// which is what I used to test the driver.  Change these
// pins to fit your own board.

#define LCD_DB4   PIN_B0
#define LCD_DB5   PIN_B1
#define LCD_DB6   PIN_B2
#define LCD_DB7   PIN_B3

#define LCD_RS    PIN_B4
#define LCD_RW    PIN_B5
#define LCD_E     PIN_B6 

// If you only want a 6-pin interface to your LCD, then
// connect the R/W pin on the LCD to ground, and comment
// out the following line.

#define USE_LCD_RW   1     

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

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


int8 const LCD_INIT_STRING[4] =
{
 0x20 | (lcd_type << 2), // Func set: 4-bit, 2 lines, 5x8 dots
 0xc,                    // Display on
 1,                      // Clear display
 6                       // Increment cursor
 };
                             

//-------------------------------------
void lcd_send_nibble(int8 nibble)
{
// Note:  !! converts an integer expression
// to a boolean (1 or 0).
 output_bit(LCD_DB4, !!(nibble & 1));
 output_bit(LCD_DB5, !!(nibble & 2)); 
 output_bit(LCD_DB6, !!(nibble & 4));   
 output_bit(LCD_DB7, !!(nibble & 8));   

 delay_cycles(1);
 output_high(LCD_E);
 delay_us(2);
 output_low(LCD_E);
}

//-----------------------------------
// This sub-routine is only called by lcd_read_byte().
// It's not a stand-alone routine.  For example, the
// R/W signal is set high by lcd_read_byte() before
// this routine is called.     

#ifdef USE_LCD_RW
int8 lcd_read_nibble(void)
{
int8 retval;
// Create bit variables so that we can easily set
// individual bits in the retval variable.
#bit retval_0 = retval.0
#bit retval_1 = retval.1
#bit retval_2 = retval.2
#bit retval_3 = retval.3

retval = 0;
   
output_high(LCD_E);
delay_cycles(1);

retval_0 = input(LCD_DB4);
retval_1 = input(LCD_DB5);
retval_2 = input(LCD_DB6);
retval_3 = input(LCD_DB7);
 
output_low(LCD_E);
   
return(retval);   
}   
#endif

//---------------------------------------
// Read a byte from the LCD and return it.

#ifdef USE_LCD_RW
int8 lcd_read_byte(void)
{
int8 low;
int8 high;

output_high(LCD_RW);
delay_cycles(1);

high = lcd_read_nibble();

low = lcd_read_nibble();

return( (high<<4) | low);
}
#endif

//----------------------------------------
// Send a byte to the LCD.
void lcd_send_byte(int8 address, int8 n)
{
output_low(LCD_RS);

#ifdef USE_LCD_RW
while(bit_test(lcd_read_byte(),7)) ;
#else
delay_us(60); 
#endif

if(address)
   output_high(LCD_RS);
else
   output_low(LCD_RS);
     
 delay_cycles(1);

#ifdef USE_LCD_RW
output_low(LCD_RW);
delay_cycles(1);
#endif

output_low(LCD_E);

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

//----------------------------
void lcd_init(void)
{
int8 i;

output_low(LCD_RS);

#ifdef USE_LCD_RW
output_low(LCD_RW);
#endif

output_low(LCD_E);

delay_ms(15);

for(i=0 ;i < 3; i++)
   {
    lcd_send_nibble(0x03);
    delay_ms(5);
   }

lcd_send_nibble(0x02);

for(i=0; i < sizeof(LCD_INIT_STRING); i++)
   {
    lcd_send_byte(0, LCD_INIT_STRING);
   
    // If the R/W signal is not used, then
    // the busy bit can't be polled.  One of
    // the init commands takes longer than
    // the hard-coded delay of 60 us, so in
    // that case, lets just do a 5 ms delay
    // after all four of them.
    #ifndef USE_LCD_RW
    delay_ms(5);
    #endif
   }

}

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

void lcd_gotoxy(int8 x, int8 y)
{
int8 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;
   }
}

//------------------------------
#ifdef USE_LCD_RW
char lcd_getc(int8 x, int8 y)
{
char value;

lcd_gotoxy(x,y);

// Wait until busy flag is low.
while(bit_test(lcd_read_byte(),7)); 

output_high(LCD_RS);
value = lcd_read_byte();
output_low(lcd_RS);

return(value);
}
#endif

I am using the LM2936-3.3V to drive both the LCD and the PIC.
The connection like this:
From PIC -> LCD
----------------------
RB0 (6) - DB4 (11)
RB1 (7) - DB5 (12)
RB2 (8) - DB6 (13)
RB3 (9) - DB7 (14)
RB4 (10) - RS (4)
RB5 (11) - RW (5)
RB6 (12) - E (6)

PIC: pin 5 to 0V and pin 14 to 3.3V
LCD: pin 1 to 0V, pin 2 to 3.3V, pin 3 to contrast 10K

However i also see nothing... i just able to contrast at line two.

 

Hi,
Are you using 16F88 or 16LF88? The 16F88 min. is 4V. While the 16LF88 min. is 2V the max freq running at 2V is 4MHz. At 3.3V the max freq is 10 MHz. That's the way I understood the charts (Figures 18-1 and 18-2 in the datasheet for 16F88). Maybe try lowering your clock speed or up the input voltage. Hope this helped.

Ed

 

Hi,
Try these too

1.
Increase delay. I guess easiest way will be to define a higher clock value in the delay function. I suggest you to increase it by 3-4 times and if all goes well then you can try and optimize it.

2.

#define LCD_DB4 PIN_B0
#define LCD_DB5 PIN_B1
#define LCD_DB6 PIN_B2
#define LCD_DB7 PIN_B3

In pin definition above try to assign the last 4 bits of the out put register!