Password/USART/CFSEQ - Electronic Circuits Projects Diagrams Free

AtomSoft · 25th June 2008, 02:55 PM

Using ASM Im trying to wrap my head on this for days now just cant focus. I want to create a USART Program for my pic which requires the user to enter a password.

I have futz old code and working on it .
I can receive info no problem like 1 character at a time now the issue is how would i store these into 1 password to check 4 charactors long?

Or would i have to create 4 separate variables and logged flag current flag?

so it checks if logged in already if so skip entire login and show menu
if not set current flag to 1 and get first character then check if curr = 4
get second and set current to 2 then check if curr = 4
get third and set current to 3 then check if curr = 4
get 4th and set current to 4 then check if curr = 4
if curr = 4 then compare "CFSEQ" each to the 4 other variable burned into chip. If correct then set logged in flag.

Does this sound overcomplicated? or just about right?

Please any tips would help alot!

Pommie · 25th June 2008, 03:10 PM

The simplest way would be a brute force compare,

Code:

Reject	call	GetChar
	xorlw	'P'
	btfss	STATUS,Z
	goto	Reject
	call	GetChar
	xorlw	'a'
	btfss	STATUS,Z
	goto	Reject
	call	GetChar
	xorlw	's'
	btfss	STATUS,Z
	goto	Reject
	call	GetChar
	xorlw	's'
	btfss	STATUS,Z
	goto	Reject
	
;if it gets here then the 4 characters matched.

Note that entering "PPass" would be invalid. So you tell people it is "xPass".

Edit, GetChar would, of course, wait for a character to be received and return it in W.

Mike.

AtomSoft · 25th June 2008, 03:21 PM

awsome! Thanks a bunch Mike.

So the GetChar would be a loop wait until char is read then have it place it in w then continue on. Nice coding!

EDIT:

I guess i just need to add a loggedin flag to determine if the user already logged in before i ask for login info.

Pommie · 25th June 2008, 03:28 PM

Quote:

Originally Posted by AtomSoft

awsome! Thanks a bunch Mike.
So the GetChar would be a loop wait until char is read then have it place it in w then continue on. Nice coding!

Yup, something like,

Code:

GetChar	btfss	PIR1,RCIF
	goto	GetChar
	movfw	RCREG
	return

Mike.

AtomSoft · 25th June 2008, 03:37 PM

Hope you dont mind i had the below alread in my code so reusing it.

Code:

rs_recv	btfss	PIR1,RCIF		;wait for a byte from RS232
		goto	rs_recv
		movf	RCREG,W			;return received byte in W
		return

Also i noticed i wont need a logged in flag really. because nothing goes back to that part of the code only a reset which would ask for pass again anyway which is good. Thanks a bunch!

AtomSoft · 25th June 2008, 03:47 PM

Need some help:

I get :

Argument out of range. Least significant bits used.

what does this mean?

Pommie · 25th June 2008, 03:51 PM

Where do you get the error? You should be able to double click on the error message and it will take you to the line with the error.

It could be that the single quotes ('P') have to be double quotes ("P").

Mike.

AtomSoft · 25th June 2008, 03:59 PM

Oh its on my code tho its here:

Code:

		list	p=18F1320
		include	<p18f1320.inc>
		;CONFIG	OSC=INTIO2,WDT=OFF,MCLRE=ON,LVP=OFF
		CONFIG	OSC = INTIO2, WDT = OFF, LVP = OFF, DEBUG = ON	

		cblock	0x00
			buff2,buff3,char,numr,bitnum,loop1,loop2,temp1,temp2
		endc

		org		0x0000
		goto	init

hello	db		0x0d,0x0a,"Hello World!",0x0d,0x0a,0x00
pa_val	db		0x0d,0x0a,"PortA = ",0x00
pb_val	db		0x0d,0x0a,"PortB = ",0x00
string3	db		0x0d,0x0a,"PORTA cleared",0x0d,0x00
string4	db		0x0d,0x0a,"PORTB cleared",0x0d,0x00
string5	db		0x0d,0x0a,"RA1 toggled",0x0d,0x00
string6	db		0x0d,0x0a,"RA4 toggled",0x0d,0x00
string7	db		0x0d,0x0a,"RA6 toggled",0x0d,0x00
string8	db		0x0d,0x0a,"RA7 toggled",0x0d,0x00
string9	db		0x0d,0x0a,"RB0 toggled",0x0d,0x00
stringa	db		0x0d,0x0a,"RB2 toggled",0x0d,0x00
stringb	db		0x0d,0x0a,"RB3 toggled",0x0d,0x00
stringc	db		0x0d,0x0a,"RB5 toggled",0x0d,0x00
stringd	db		0x0d,0x0a,"LEDs flashed",0x0d,0x00 
stringe	db		0x0d,0x0a,"RA3 toggled",0x0d,0x00  
stringf	db		0x0d,0x0a,"Please Enter Code:",0x0d,0x00    ; Happened when i added this line 
menu	db		0x0d,0x0a,0x0d,0x0a,"Junebug PIC18F1320",0x0d,0x0a,0x0d,0x0a
		db		"      A - PORTA Status",0x0d,0x0a
		db		"      B - PORTB Status",0x0d,0x0a
		db		"      C - Clear PORTA bits 1,2,3,4,6,7",0x0d,0x0a
		db		"      D - Clear PORTB bits 0,5",0x0d,0x0a
		db		"      H - Hello World!",0x0d,0x0a
		db		"      L - Flash LEDs",0x0d,0x0a
		db		"1,2,3,4,6,7 - Toggle PORTA pins ",0x0d,0x0a
		db		"0,5 - Toggle PORTB pins ",0x0d,0x0a
		db		"<ENTER> - Display menu",0x0d,0x0a
		db		"Modded by Jason aka AtomSoft, thx futz!",0x0d,0x0a,0x0d,0x0a,0x00

init	bsf		OSCCON,IRCF2	;set to 8MHz clock
		bsf		OSCCON,IRCF1
		bsf		OSCCON,IRCF0
		setf	ADCON1			;set PortA to all digital
		clrf	TRISA			;set PortA pins to outputs
		clrf	LATA			;turn off LEDs
		movlw	b'00010010'		;set PORTB data directions
		movwf	TRISB
		call	rs_init			;init rs232
;STARTUP HERE MAIN
      ;
Reject
		movlw	stringf
		call	strsend  		;Send Login text
                ; 
		call	rs_recv
		xorlw	'P'
		btfss	STATUS,Z
		goto	Reject
		call	rs_recv
		xorlw	'a'
		btfss	STATUS,Z
		goto	Reject
		call	rs_recv
		xorlw	's'
		btfss	STATUS,Z
		goto	Reject
		call	rs_recv
		xorlw	's'
		btfss	STATUS,Z
		goto	Reject
ShowMen							;if it gets here then the 4 characters matched. 

		movlw	menu			;send menu
		call	strsend                 ;

Is it possible i have too many db things?

Pommie · 25th June 2008, 04:10 PM

It looks like stringf is greater than 255 and so you have the error. You need a different way to store (and access) messages. For now you could shorten your other messages (change "toggled" to "Tg") in order to see if it works and then work out how to have a message bank bigger than 256 bytes.

Mike.
P.S. Bed time for me now. If you get stuck I'll look tomorrow.

AtomSoft · 25th June 2008, 04:28 PM

ok thanks! BTW that Tg fixed it now how to learn the rest.

Pommie · 25th June 2008, 04:33 PM

Good to hear it's working.

And now I really am going to bed - 2.30 here.

Mike.

AtomSoft · 25th June 2008, 05:16 PM

ok cool thanks look into eeprom (de) Good night its 1:16pm here

AtomSoft · 25th June 2008, 06:11 PM

the other code would send them to reject to soon doing it that way anyone with time can get the pass quick by simple trying every character 1 by 1.

Code:

Reject	
		movlw	stringf
		call	strsend  		;Send Login text

		movlw	0x00
		movwf	temp3

		call	rs_recv
		xorlw	'P'
		btfss	STATUS,Z
		INCF	temp3
		bcf		STATUS,Z
		call	rs_recv
		xorlw	'a'
		btfss	STATUS,Z
		INCF	temp3
		bcf		STATUS,Z
		call	rs_recv
		xorlw	's'
		btfss	STATUS,Z
		INCF	temp3
		bcf		STATUS,Z
		call	rs_recv
		xorlw	's'
		btfss	STATUS,Z
		INCF	temp3

		movlw	0x01
		CPFSLT	temp3
		goto	Reject2
		goto	ShowMen
Reject2
		movlw	nogo			;send incorrect info
		call	strsend
		goto	Reject
		
ShowMen							;if it gets here then the 4 characters matched.

		movlw	menu			;send menu
		call	strsend

This lets them enter all 4 then if correct lets them in

atferrari · 25th June 2008, 06:11 PM

We are having kind of an electronic pijama party here....

AtomSoft · 25th June 2008, 07:55 PM

I sort of figured out a way to save tons of space instead of hard coding the text into the chip i can hard code into my own vb6 program and just send as many commands as needed this way i can send and receive my way ...

Like if i run out of 0xff bytes to send i can use 0xff as a signal for second set of commands and send another for which in the second set.

Kind of like Bank Selectoin (RP0)

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25th June 2008, 02:55 PM	(permalink)
AtomSoft	Password/USART/CFSEQ Using ASM Im trying to wrap my head on this for days now just cant focus. I want to create a USART Program for my pic which requires the user to enter a password. I have futz old code and working on it . I can receive info no problem like 1 character at a time now the issue is how would i store these into 1 password to check 4 charactors long? Or would i have to create 4 separate variables and logged flag current flag? so it checks if logged in already if so skip entire login and show menu if not set current flag to 1 and get first character then check if curr = 4 get second and set current to 2 then check if curr = 4 get third and set current to 3 then check if curr = 4 get 4th and set current to 4 then check if curr = 4 if curr = 4 then compare "CFSEQ" each to the 4 other variable burned into chip. If correct then set logged in flag. Does this sound overcomplicated? or just about right? Please any tips would help alot! __________________ My YouTube Videos! My Favorite Stores: dipmicro Electronics SparkFun Electronics Futurlec BG Micro Last edited by AtomSoft; 25th June 2008 at 02:56 PM.

25th June 2008, 03:10 PM	(permalink)
Pommie	The simplest way would be a brute force compare, Code: Reject call GetChar xorlw 'P' btfss STATUS,Z goto Reject call GetChar xorlw 'a' btfss STATUS,Z goto Reject call GetChar xorlw 's' btfss STATUS,Z goto Reject call GetChar xorlw 's' btfss STATUS,Z goto Reject ;if it gets here then the 4 characters matched. Note that entering "PPass" would be invalid. So you tell people it is "xPass". Edit, GetChar would, of course, wait for a character to be received and return it in W. Mike. Last edited by Pommie; 25th June 2008 at 03:12 PM.

25th June 2008, 03:21 PM	(permalink)
AtomSoft	awsome! Thanks a bunch Mike. So the GetChar would be a loop wait until char is read then have it place it in w then continue on. Nice coding! EDIT: I guess i just need to add a loggedin flag to determine if the user already logged in before i ask for login info. __________________ My YouTube Videos! My Favorite Stores: dipmicro Electronics SparkFun Electronics Futurlec BG Micro Last edited by AtomSoft; 25th June 2008 at 03:22 PM.

25th June 2008, 03:37 PM	(permalink)
AtomSoft	Hope you dont mind i had the below alread in my code so reusing it. Code: rs_recv btfss PIR1,RCIF ;wait for a byte from RS232 goto rs_recv movf RCREG,W ;return received byte in W return Also i noticed i wont need a logged in flag really. because nothing goes back to that part of the code only a reset which would ask for pass again anyway which is good. Thanks a bunch! __________________ My YouTube Videos! My Favorite Stores: dipmicro Electronics SparkFun Electronics Futurlec BG Micro

25th June 2008, 03:47 PM	(permalink)
AtomSoft	Need some help: I get : Argument out of range. Least significant bits used. what does this mean? __________________ My YouTube Videos! My Favorite Stores: dipmicro Electronics SparkFun Electronics Futurlec BG Micro

25th June 2008, 03:51 PM	(permalink)
Pommie	Where do you get the error? You should be able to double click on the error message and it will take you to the line with the error. It could be that the single quotes ('P') have to be double quotes ("P"). Mike.

25th June 2008, 04:10 PM	(permalink)
Pommie	It looks like stringf is greater than 255 and so you have the error. You need a different way to store (and access) messages. For now you could shorten your other messages (change "toggled" to "Tg") in order to see if it works and then work out how to have a message bank bigger than 256 bytes. Mike. P.S. Bed time for me now. If you get stuck I'll look tomorrow.

25th June 2008, 04:28 PM	(permalink)
AtomSoft	ok thanks! BTW that Tg fixed it now how to learn the rest. __________________ My YouTube Videos! My Favorite Stores: dipmicro Electronics SparkFun Electronics Futurlec BG Micro

25th June 2008, 04:33 PM	(permalink)
Pommie	Good to hear it's working. And now I really am going to bed - 2.30 here. Mike.

25th June 2008, 05:16 PM	(permalink)
AtomSoft	ok cool thanks look into eeprom (de) Good night its 1:16pm here __________________ My YouTube Videos! My Favorite Stores: dipmicro Electronics SparkFun Electronics Futurlec BG Micro

25th June 2008, 06:11 PM	(permalink)
atferrari	We are having kind of an electronic pijama party here.... __________________ Agustín Tomás In theory, there is no difference between theory and practice. In practice, however, there is.

25th June 2008, 07:55 PM	(permalink)
AtomSoft	I sort of figured out a way to save tons of space instead of hard coding the text into the chip i can hard code into my own vb6 program and just send as many commands as needed this way i can send and receive my way ... Like if i run out of 0xff bytes to send i can use 0xff as a signal for second set of commands and send another for which in the second set. Kind of like Bank Selectoin (RP0) __________________ My YouTube Videos! My Favorite Stores: dipmicro Electronics SparkFun Electronics Futurlec BG Micro