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How to connect an LCD display with PIC16f84?

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tzviel

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Hello everybody,

I have bought a LCD display but I don't know how to connect it to the PIC.
The display is EI62585 ,C20408tr-08 ,050316 (i don't know which number is the moduls' number).

Does anybody has the datasheet of this display or a circuit with PIC16f84?

Thank.
 

ei62585

Check this tutorial chapter 6.
You will find an example for PIC16F877 with LCD. However, the same connection and code works with 16F84A.
 

pic 16f84 lcd

i think there is nothing to do with LCD part number.For any LCD there are six steps for initiliazion you will get those any where from uc books to internet just study that you can interface any LCd to any uc.
this is my personal experience

--pradeep--
 

lcd with pic16f84

deepu_ttc,..
You are right. But, how you will know the pins without the datasheet.

I suffered this problem with two LCD's extracted from a broken phone set. I couldn't find the datasheet and there's nothing written on the LCD itself.
 

lcd_2x16.c

tzviel said:
Hello everybody,

I have bought a LCD display but I don't know how to connect it to the PIC.
The display is EI62585 ,C20408tr-08 ,050316 (i don't know which number is the moduls' number).

Does anybody has the datasheet of this display or a circuit with PIC16f84?

Thank.
Click to expand...
Code: 
////////////////////////////////////////////////////////////////////////////
////                          LCD_2x16.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                    ////
////                      \1..2 clear line                              ////
////                                                                    ////
////  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 1996,1997 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:
//
//     C7  enable
//     C5  rs
//     C6  rw
//
//     B4  D4
//     B5  D5
//     B6  D6
//     B7  D7
//
//   LCD pins D0-D3 are not used and PIC B3 is not used.

//   mapped such to allow a keyboard on port B

struct lcd_pin_map_c 
        {                            //      This structure is overlayed
           boolean unused1;          // C0    
           boolean unused2;          // C1    
           boolean unused3;          // C2    
           boolean unused4;          // C3    
           boolean unused5;          // C4    
           boolean rs;               // C5   
           boolean rw;               // C6   
           boolean enable;           // C7   
        } lcd_c;

struct lcd_pin_map_b 
        {                            
           boolean unused3;          // B0   
           boolean unused4;          // B1   
           boolean unused5;          // B2   
           boolean unused6;          // B3   
           int     data : 4;         // B4 to B7    Data Bits.
        } lcd_b;

#byte lcd_c = 7                      // This puts the entire structure
                                     // on to port C (at address 7)
#byte lcd_b = 6                      // This puts the entire structure
                                     // on to port B (at address 6)

#define lcd_type 2           // 0=5x7, 1=5x10, 2=2 lines, 4=4 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_b const LCD_WRITE = {1,1,1,1,0}; // For write mode all pins are out
STRUCT lcd_pin_map_b const LCD_READ = {1,1,1,1,15}; // For read mode data pins are in


byte lcd_read_byte() 
  {
      byte low,high;

      set_tris_c(0x08);
      set_tris_b(LCD_READ);
      lcd_c.rw = 1;
      delay_cycles(1);
      lcd_c.enable = 1;
      delay_cycles(1);
      high = lcd_b.data;
      lcd_c.enable = 0;
      delay_cycles(1);
      lcd_c.enable = 1;
      delay_us(1);
      low = lcd_b.data;
      lcd_c.enable = 0;
      set_tris_b(LCD_WRITE);
      return( (high<<4) | low);
  }


void lcd_send_nibble( byte n ) 
  {
      lcd_b.data = n;
      delay_cycles(1);
      lcd_c.enable = 1;
      delay_us(2);
      lcd_c.enable = 0;
  }


void lcd_send_byte( byte address, byte n ) 
  {
      lcd_c.rs = 0;
      while ( bit_test(lcd_read_byte(),7) ) ;
      lcd_c.rs = address;
      delay_cycles(1);
      lcd_c.rw = 0;
      delay_cycles(1); 
      lcd_c.enable = 0;
      lcd_send_nibble(n >> 4);
      lcd_send_nibble(n & 0xf);
  }


void lcd_init() 
  {
    byte i;

    set_tris_c(0x08);
    set_tris_b(LCD_WRITE);
    lcd_c.rs = 0;
    lcd_c.rw = 0;
    lcd_c.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<2)  {address=0;}
   if(y==2) {address=lcd_line_two;}
   if(y>2)  {address=0;}
   address+=x-1;
   lcd_send_byte(0,0x80|address);
  }

void lcd_putc( char c) 
  {int tmp;
   switch (c) 
     {
     case '\f'   : lcd_send_byte(0,1);
                   delay_ms(2);
                   break;
     case '\n'   : lcd_gotoxy(1,2);        break;
     case '\1'   : for (tmp=1;tmp<21;tmp++)
                      {lcd_gotoxy(tmp,1);
                       lcd_send_byte(1,0x20);
                      }
                   lcd_gotoxy(1,1);
                   break;
     case '\2'   : for (tmp=1;tmp<21;tmp++)
                      {lcd_gotoxy(tmp,2);
                       lcd_send_byte(1,0x20);
                      }
                   lcd_gotoxy(1,2);
                   break;
     case '\b'   : lcd_send_byte(0,0x10);  break;
     default     : lcd_send_byte(1,c);     break;
   }
}

void lcd_put_bcd( int c) 
  {
   int tmp;
    tmp = ((c & 0xF0)/0x10)+0x30;
    c = (c & 0x0F)+0x30;
    lcd_send_byte(1,tmp);
    lcd_send_byte(1,c);
   return;
  }

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

   lcd_gotoxy(x,y);
   lcd_c.rs=1;
   value = lcd_read_byte();
   lcd_c.rs=0;
   return(value);
  }

Added after 47 minutes:

btw I didn't tell u that all 2x16 lcd are commonly compatible with HD44780U driver
so don't worry just take care about initialize delays and go:eek:n just try to modify it's easy task
here you are compatible code for 16f84x
Code: 
; 1		Vss -	Ground, 3rd pin of the potentiometer
; 2 	Vcc	-	5V DC, 1st pin of the potentiometer
; 3 	Vee	-	Middle pin of the potentiometer
; 4 	RS	-	RA0		(Data - 1, Instruction - 0)
; 5 	R/W	-	RA1		(R - 1, W - 0)
; 6		E	-	RA2		(Enable Pulse)
; 7		DB0	-	RB0		(LSB)
; 8		DB1	-	RB1
; 9		DB2	-	RB2
; 10	DB3	-	RB3		(Lower 4 bits)
; 11	DB4 -	RB4		(Upper 4 bits)
; 12	DB5	-	RB5
; 13	DB6	-	RB6
; 14	DB7	-	RB7		(MSB)

; Instruction Cycle Time = 1 / (4MHz / 4) = 1us per instruction

;***********************************************************************************

	LIST	p=16F84
	include	"p16f84.inc"
	__CONFIG _HS_OSC & _CP_OFF & _WDT_OFF & _PWRTE_OFF
	errorlevel -302

N 			EQU 0x0C
FIXDELAY	EQU 0x0D

;***********************************************************************************
		ORG 0x00
		GOTO START

START	CLRF	PORTA		; Clear PortA
		CLRF	PORTB		; Clear PortB
		MOVLW	0x00		
		BSF		STATUS, RP0	; Select Bank 1
		MOVWF	TRISA		; Set Port A to output
		MOVWF	TRISB		; Set Port B to output
		BCF		STATUS, RP0	; Select Bank 0
		MOVLW	0xE6		; Call for 46ms delay
		CALL 	NDELAY		; Wait for VCC of the LCD to reach 5V

INITLCD	BCF		PORTA, 0	; Clear RS to select Instruction Reg.
		BCF		PORTA, 1	; Clear R/W to write
		
		MOVLW	B'00111111'	; Function Set to 8 bit
		MOVWF	PORTB
		CALL	ENABLEPULSE
		MOVLW	0x15		; Call for 4.2ms delay
		CALL 	NDELAY

		MOVLW	B'00111111'	; Function Set to 8 bit again
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY200	; Call for 200us delay

		MOVLW	B'00111111'	; Function Set to 8 bit again, to make sure it's 8 bit, really
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY200	; Call for 200us delay

		MOVLW	B'00111011'	; Function Set to 8 bits, 2 lines and 5x7 dot matrix
		MOVWF 	PORTB
		CALL	ENABLEPULSE
		CALL	DELAY50		; Call 50us delay and wait for instruction completion

		MOVLW	B'00001000'	; Display OFF
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL	DELAY50		; Call 50us delay and wait for instruction completion

		MOVLW	B'00000001'	; Clear Display
		MOVWF	PORTB
		CALL	ENABLEPULSE
		MOVLW	0x09		; Call 1.8ms delay and wait for instruction completion				
		CALL	NDELAY		

		MOVLW	B'00000010'	; Cursor Home
		MOVWF	PORTB
		CALL	ENABLEPULSE
		MOVLW	0x09		; Call 1.8ms delay and wait for instruction completion				
		CALL	NDELAY
		
		MOVLW	B'00001100'	; Display ON, Cursor OFF, Blinking OFF
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL	DELAY50		; Call 50us delay and wait for instruction completion

		MOVLW 	B'00000110'	; Entry Mode Set, Increment & No display shift
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL	DELAY50		; Call 50us delay and wait for instruction completion

; End of Initialization of LCD.

MAIN	BSF		PORTA, 0	; Set RS to select Data Reg.
		BCF		PORTA, 1	; Clear R/W to write

		MOVLW	A'k'		; Send char to be displayed on LCD
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY50		; Wait for instruction completion.

		MOVLW	A'i'		; Send char to be displayed on LCD
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY50		; Wait for instruction completion.

		MOVLW	A'n'		; Send char to be displayed on LCD
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY50		; Wait for instruction completion.

		
		MOVLW	A'g'		; Send char to be displayed on LCD
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY50		; Wait for instruction completion.

		MOVLW	A'_'		; Send char to be displayed on LCD
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY50		; Wait for instruction completion.

		
		MOVLW	A'r'		; Send char to be displayed on LCD
		MOVWF	PORTB
		CALL	ENABLEPULSE
		CALL 	DELAY50		; Wait for instruction completion.


FOREVER	NOP
		GOTO FOREVER

;***********************************************************************************
; Enable Pulse for writing or reading instructions or data
;***********************************************************************************

ENABLEPULSE	BCF	PORTA, 2
			CALL DELAY50
			BSF	PORTA, 2	; 50us E-Pulse
			CALL DELAY50
			BCF PORTA, 2
			RETURN

;***********************************************************************************
; N DELAY SUBROUTINE, delay in multiples of 200us up to 200us*255 = 51ms (or more)
;***********************************************************************************

NDELAY
			MOVWF N				; N is delay multiplier
NOTOVER		CALL DELAY200		; Call for 200us
			DECFSZ N, 1			; Decrease N by 1
			GOTO NOTOVER		; The delay isn't done
			RETURN
	
;***********************************************************************************
; FIXED 200us DELAY (Possibly more due to execution time of the DECFSZ instruction.)
;***********************************************************************************

DELAY200	
			MOVLW 0xC8			; 200 LOOPS
			MOVWF FIXDELAY		; 200us fixed delay
NOTDONE200	DECFSZ FIXDELAY, 1 	; Decrement of FIXDELAY
			GOTO NOTDONE200		; If 200us isn't up go back to NOTDONE200
			RETURN				; If 200us is up then return to instruction.

;***********************************************************************************
; FIXED 50us DELAY (Possibly more due to execution time of the DECFSZ instruction.)
;***********************************************************************************

DELAY50	
			MOVLW 0x32			; 50 LOOPS
			MOVWF FIXDELAY		; 50us fixed delay
NOTDONE50	DECFSZ FIXDELAY, 1 	; Decrement of FIXDELAY
			GOTO NOTDONE50		; If 50us isn't up go back to NOTDONE50
			RETURN				; If 50us is up then return to instruction.

			END
 

lcd_gotoxy () ccs

hi there,

you might find this site useful

http://www.rentron.com/Myke1.htm

we are also trying to interface it to the PIC and this might also be useful to you if you are saving IO lines
 

16f84 y lcd con lcd_gotoxy(x,y)

tzviel said:
Hello everybody,

I have bought a LCD display but I don't know how to connect it to the PIC.
The display is EI62585 ,C20408tr-08 ,050316 (i don't know which number is the moduls' number).

Does anybody has the datasheet of this display or a circuit with PIC16f84?

Thank.
Click to expand...

If you could not decode it, never mind, you can take 2 or 3 close shot photos and put it on net. Then, indicate whether it has 16 pin connector, has a back-lit facility etc. If needed the shop where from you got it, will provide the data for you.
Sarma
 

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