PIC16f913 and lcd

[Arun Sukumaran]

haiii friends…..

i m a begginer in PIC…. i tried a code in assembly for LCD with PIC 16F913…. the code is giving output to PORTA while i’m checking it with MPSIM… but after dumping it to PIC the LCD shows only 5×7 blocks but not displaying any character…please anybody help me… i post my code here….

 

 

 

 

    list  p=16f913      ; list directive to define processor
   #include <p16f913.inc>

   org 0x00

     STATUS equ 03h

   PORTA equ 05h
   PORTC equ 07h
   TRISA equ 85h
   TRISB equ 86h
   TRISC equ 87h
   bsf STATUS,05
   bcf STATUS,06

   movlw 07h
   movwf CMCON0
   clrf ANSEL
   clrf PORTA
 
   movlw 0xfc
   movwf TRISC
   bcf STATUS,05
 
   COUNT1 equ 50h
   COUNT2 equ 51h
   R1 equ 22h
   R2 equ 23h
   R3 equ 24h
   R4 equ 25h
   temp equ 26h
 
  start 

 

    movlw 38h
    call mask1
    movlw 28h
    call mask1
    movlw 28h
    call mask1
    movlw 0Ch
    call mask1
    movlw 06h
    call mask1
    movlw 80h
    call mask1
  
    movlw ‘H’
    call mask2
    movlw “a”
    call mask2
    movlw “i”
    call mask2

  here      goto here

  mask1

   

    movwf temp
    movlw 0xf0
    movwf R1
    movlw 0x0f
    movwf R2
    movf temp,w
    andwf R1,1
    swapf R1,1
    andwf R2,1
 
    movf R1,w
    call cmd
    movf R2,w
    call cmd
    return

 

  mask2

   

    movwf temp
    movlw 0xf0
    movwf R3
    movlw 0x0f
    movwf R4
    movf temp,w
    andwf R3,1
    swapf R3,1
    andwf R4,1
  
    movf R3,w
    call dat
    movf R4,w
    call dat
    return
  

 

cmd 

 
    movwf PORTA
    bcf PORTC,0
    bsf PORTC,1
    call delay
    bcf PORTC,1
    return

 

  dat

    movwf PORTA
    bsf PORTC,0
    bsf PORTC,1
    call delay
    bcf PORTC,1
    return

 

  delay 
  
    movlw d’250′
    movwf COUNT2
  loop4
    movlw d’250′
    movwf COUNT1
  loop3 decfsz COUNT1,1
    goto loop3
    decfsz COUNT2,1
    goto loop4

    return
  
   end
   

   

[Arun Sukumaran]

please anybody help me…..

[AJISH ALFRED]

Hi Arun,

If you are getting black boxes in LCD, that means your LCD is not getting initialized. Most probably the issue is in your circuit connections. Please check the connections for any short cicuit or loose contact or misconnections.

[Arun Sukumaran]

hi ajish….

 

i checked it with another hex file(i have only the hex file)…. its working properly….

do you checked my initialisation section in the code…. is there any problem…

[Author]

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