[SOLVED] Interfacing LCD with Keyboard asembler

[Maxeyas]

Hello edaboard. I'm Max,

I'm trying to display on LCD pressed key & there is serval issues:

1) Before pressing any key when reseting, it will show the address 0h as pressed (It shows '**' twice on the LCD when resetting).
2) Each time i press a key it shows it twice (There is 2 capacitors, one connected to KBM "104->10pF" & second to OSC (not sure about the value, probably the same)).

Those issues should be fixed first.

I want afterwards to check if First line is full of pressed keys & shift to second line if it is. How I check & apply?

#0C0h - The 74hc138 address which activates the LCD.
#20h - The 74hc138 address which activates Keyboard.

Explaination:
Using INT0 in P3.2 to determinate if key pressed. If the signal going low the interrupt is initiated.
Which is why i'm setting IT0 '1' & IE as 10000001.

* No I cannot replace any device or capacitor or resistor. Only if its 100% neccesery which means broken.
I wonder if needed schematics & datasheet. Its just a software issues. Help would be appreciated.

Here is the full code:

; Defines
RS EQU P1.0 ;Register Select
EN EQU P1.1 ;Enable Pin

org 0h
ljmp Main
org 3h
mov P0, #0FFh
mov P2, #20h
mov A, P0
anl A, #0Fh
ljmp ScanKeys
KeyPressed:
lcall SendData
reti

Main:
lcall InitLCD
mov IE,#10000001B // ES=1,EX0=1
setb IT0
sjmp $
	
InitLCD:
;50ms Delay before initialization
lcall LongDelay

;Function Set - 2 lines 8bit
mov A, #38h
lcall SendCommand

;Display Control - display on, cursor off
mov A, #0Ch
lcall SendCommand

;Entry mode set - auto-increment cursor and disable shift mode
mov A, #06h
lcall SendCommand

;Display Clear - clearing the screen and setting cursor home
lcall ClearDisplay
ret

SecondLine:
mov A, #0C0h
lcall SendCommand
ret

ClearDisplay:
mov A, #01h
lcall SendCommand
ret

SendCommand:
mov P2, #0C0h
clr RS ; Setting 0 in RS (0=commands,1=data)
mov P0, A
setb EN ; Setting 1 in EN (pulse)
clr EN ; Setting 0 in EN (send pulse)
lcall Delay
ret

SendData:
mov P2, #0C0h ;
setb RS ; Setting 1 in RS (0=commands,1=data)
mov P0, A
setb EN ; Setting 1 in EN (pulse)
clr EN ; Setting 0 in EN (send pulse)
lcall Delay
ret

Delay: ; 100x20 = 2000us = 2 ms
mov R7, #100
D3: mov R6, #20
djnz R6,$
djnz R7,D3
ret

LongDelay: ; 250x200 = 50000us = 50ms
mov R7, #250
D4: mov R6, #200
djnz R6,$
djnz R7,D4
ret

ScanKeys:
cjne A,#0,KeyCheck1
mov A, #'*'
lcall SendData
ljmp KeyPressed
KeyCheck1:
cjne A,#1,KeyCheck2
mov A, #'7'
lcall SendData
ljmp KeyPressed
KeyCheck2:
cjne A,#2,KeyCheck3
mov A, #'4'
lcall SendData
ljmp KeyPressed
KeyCheck3:
cjne A,#3,KeyCheck4
mov A, #'1'
lcall SendData
ljmp KeyPressed
KeyCheck4:
cjne A,#4,KeyCheck5
mov A, #0
lcall SendData
ljmp KeyPressed
KeyCheck5:
cjne A,#5,KeyCheck6
mov A, #'8'
lcall SendData
ljmp KeyPressed
KeyCheck6:
cjne A,#6,KeyCheck7
mov A, #'5'
lcall SendData
ljmp KeyPressed
KeyCheck7:
cjne A,#7,KeyCheck8
mov A, #'2'
lcall SendData
ljmp KeyPressed
KeyCheck8:
cjne A,#8,KeyCheck9
;mov A, #'#' Clearing LCD
lcall ClearDisplay
ljmp KeyPressed
KeyCheck9:
cjne A,#9,KeyCheck10
mov A, #'9'
lcall SendData
ljmp KeyPressed
KeyCheck10:
cjne A,#0Ah,KeyCheck11
mov A, #'6'
lcall SendData
ljmp KeyPressed
KeyCheck11:
cjne A,#0Bh,KeyCheck12
mov A, #'3'
lcall SendData
ljmp KeyPressed
KeyCheck12:
cjne A,#0Ch,KeyCheck13
mov A, #'D'
lcall SendData
ljmp KeyPressed
KeyCheck13:
cjne A,#0Dh,KeyCheck14
mov A, #'C'
lcall SendData
ljmp KeyPressed
KeyCheck14:
cjne A,#0Eh,KeyCheck15
mov A, #'B'
lcall SendData
ljmp KeyPressed
KeyCheck15:
mov A, #'A'
lcall SendData
ljmp KeyPressed

end