The differences between 16F84 and 16F628 are only tiny, and it was the 'modern' replacement for it last century.

To alter 84 code to 628, you just need to:

1) Alter the fuse settings and heard of the assembly file.

2) Alter the GPR start address.

2) Turn off the analogue comparators.

You can check my tutorials to see what these all look like.

Originally Posted by _ab

What part in the code should i change to convert it to the pic16f628???

You have asked the question badly. It is not about changing from 16F84 to 16F628. The original author had already provided correct source code for the 16F628. It is the function you required not being provided in the F628 source code. So it is a question of modifying the 16F628 source code to include your requirement.

The change required is easily done. See below, change marked with "<<<<<<".

Code:

;**********************************************************************
;                                                                     *
;    Filename:	    cl2.asm                                           *
;    Date:                                                            *
;    File Version:  Combination lock rewritten                        *
;                                                                     *
;    Author:        Peter Jakab <el@jap.hu>                           *
;                   http://jap.hu/electronic/                         *
;**********************************************************************
;..............
;
pulseout				; # operates output

		movf PORTA, W	;get port A into W <<<<<<<<<<
		xorlw 0x04 	;toggle RA2      <<<<<<<<<<
		movwf PORTA




		movlw msg_line
		call lcd_cmdout
		movlw msg_ok
		call lcd_strout

		movlw pulsewidth
		movwf dcnt2

out0		movlw d'200'
		call udelay
		decfsz dcnt2, F
		goto out0

		goto loop

Originally Posted by _ab

Thank you very much for replying me......
I changed the code as you say ,but i have the same results of the circuit..... :-(

Somewhere else the author reset the output, missed that earlier. Try this:

Code:

warm		movlw 0xf0
		call beep
		call eep_read ; read code from eeprom to ram at cod

loopx	clrf PORTA ; clear output   <<<<<<<<<<< 

loop		movlw msg_line    ;<<<<<<<<<<<<
		call lcd_cmdout
		movlw msg_code
		call lcd_strout
		
		call read ; read code from keyboard into readbuf
		movlw cod
		call compbuf ; compare code in readbuf with code at cod
		bnz loop ; the code is different

Originally Posted by _ab

And one last question is it possible,when you first power up the circuit the output to be in the off state instead of the on state that it is now?????

I don't know why the output is default ON at power up. Could be due to LCD routines.

Anyway, you can try to replace:

Code:

loopx	clrf PORTA ; clear output

with these two instructions:

Code:

loopx   movlw  0x04     ;<<<<<<<<<
        movwf PORTA     ;<<<<<<<<<

loop     movlw msg_line

to see if it works.

From what I read from .asm and see in the schematic, I would say that the RELAY output is defaulting to its unenergized state. The BC transistor drivers is not inverted and the PIC code clears PortB on startup. Is this the output to which you are asking?

If the relay in your setup is always closing the contacts between relay pins S and P, you might be using a relay with normally closed (N.C) contacts as opposed to normally open (N.O.) contacts. Or you have a single-pole-double-throw (SPDT) relay and are using the wrong throw pin.

With all the versions of toggling floating around and since I do not trust that experimental toggle (ON/OFF) source, I suggest you perform an absolute test. Remove relay and the transistor from PIC and remove relay from transistor. Verify relay is connected to work as N.O. Reconnect relay to transistor, bias relay base with 5v and verify relay works as N.O. Before connecting relay/transistor to PIC, power on the PIC and monitor RB2 output from power up, which should be low. If its high then the asm code is toggling prematurely. I can see why because dcnt2 is use in multiple places. Just use a dedicated variable for Relay output and toggle it instead of a commonly shared variable.

Originally Posted by _ab

I forgot to mention that i have a led right now in the output,instead the relay.(i don't know if that matters...)So It worked!!!!!!!But when i power up the circuit i have a pulse.The led lights for a moment and then it goes to the off state....(it's not much problem)

It matters a lot. How was the LED connected?

From +5V to RA2 or from RA2 to 0V?