Combinaton Gate access

[Archangel]

could be replace by the single line bellow.

LOOKUP ByteA,[0,1,2,3,"A",4,5,6,"B",7,8,9,"C","*",0,"#","D"],ByteA

Or store the table in the EEPROM, then read from it..

DATA @1,1,2,3,"A",4,5,6,"B",7,8,9,"C","*",0,"#","D"
'
'
'
'
'
Read ByteA, ByteA

ALLRIGHTY THEN,
Hi Steve, Darrel and all,
For starters . . . Lookup table listed will do the kepad remapping of my long and convouluted code? Cool, I must learn more about this, also how to set up eprom, as I have never figured that out.
Darrel, you said my code never went to gosub, . . . the if bytea != 0 then gosub combo, will not do it?
before you and Steve posted, but after skimask did I wrote the following

@MyConfig = _HS_OSC & _WDT_OFF & _PWRTE_ON & _LVP_OFF 
@MyConfig = MyConfig & _BODEN_OFF 
@ __config  MyConfig
'@ __CONFIG _HS_OSC & _WDT_ON & _PWRTE_ON  & _LVP_OFF & _CP_OFF
Define PIC16F877A
@ errorlevel -230
CMCON  = 7  
ADCON1 = 7 
define OSC 20
TrisD = %00000000

DEFINE LCD_DREG PORTA
    DEFINE LCD_DBIT 0
    DEFINE LCD_RSREG PORTA
    DEFINE LCD_RSBIT 5
    DEFINE LCD_EREG PORTA
    DEFINE LCD_EBIT 4
    DEFINE LCD_BITS 4
    DEFINE LCD_LINES 4

    include "keypad.bas"
pause 1000
lcdout 254,1
lcdout 254,128,"PIC Self Test"
pause 1000
    
    DEFINE KEYPAD_ROW        4        ' 4 ROW keypad       
    DEFINE KEYPAD_ROW_PORT   PORTB    ' ROW port = PORTB
    DEFINE KEYPAD_ROW_BIT    4        ' ROW0 = PORTB.4
    DEFINE KEYPAD_COL        4        ' 3 COL keypad
    DEFINE KEYPAD_COL_PORT   PORTB    ' COL port = PORTB
    DEFINE KEYPAD_COL_BIT    0        ' COL0 = PORTB.1
    DEFINE KEYPAD_DEBOUNCEMS 50       ' debounce delay = 50 mSec
    DEFINE SCAN_ONCE         1

    OPTION_REG.7 = 0        ' Enable internal crap pull-up :D

    PORTB = 0             '  
    TRISB = %11110000     '
    Flags = 0  
    ByteA var byte         '
    Combocount var byte 
        INTCON = %10001000    ' Enable global interrupt
                          ' Enable interrupt on PORTB change
    on interrupt goto KeypadInt
    CLEAR
lcdout 254,128," Initializing"
LCDOUT 254,192,"System"
pause 1000
Portd.2 = 0
combocount = 0

Init:    
    lcdout $FE,1
    LCDOUT 254,128,"AUTHORIZATION"
    LCDOUT 254,192,"REQUIRED TO OPEN"
    LCDOUT 254,153,"THIS GATE"
    LCDOUT 254,212,"KEY ENTRY CODE"
 disable
KeypadINT:    
@ READKEYPAD _ByteA
    TRISB=%11110000
    PORTB=0
    INTCON.0=0
    resume
enable   
    
    
Start:
    if ByteA then
    If ByteA = 4  then ByteA = "A"
    if ByteA = 5  then ByteA = 4
    if ByteA = 6  then ByteA = 5
    if ByteA = 7  then ByteA = 6
    if ByteA = 8  then ByteA = "B"
    if ByteA = 9  then ByteA = 7
    if ByteA = 10 then ByteA = 8
    if ByteA = 11 then ByteA = 9
    if ByteA = 12 then ByteA = "C"
    if ByteA = 13 then ByteA = "*"
    if ByteA = 14 then ByteA = 0
    if ByteA = 15 then ByteA = "#"
    if ByteA = 16 then ByteA = "D"
    if ByteA != 0 then  gosub combo
        
        ByteA = 0
        pause 1000
        goto init
        'else
           
else   
endif
goto start

         


combo:
LCDOUT $FE,1,"Key=",dec ByteA
if ((ByteA = 7) and (combocount = 0)) then
combocount = %00000001
pause 1000
else
combocount = 0
endif
if ((ByteA = 8) and (combocount = %00000001)) then
 combocount = %00000011
pause 1000
else
combocount = 0
endif
if ((ByteA = 65) and (combocount = %00000011)) then
combocount = %00000111
pause 1000
else
combocount = 0
endif
if ((ByteA = 5) and (combocount = %00000111)) then  
combocount = %000011111
pause 1000
else
combocount = 0
endif
if ((ByteA =68) and (combocount = %00001111)) then  
combocount = %00011111
pause 1000
else
combocount = 0
endif
if combocount = %00011111 then  PortD.2 = 1
lcdout 254,1
pause 10 
lcdout 254,128,"Gate Opening" : pause 30000
lcdout 254,1
pause 10
lcdout 254,192,"Gate Closing" : pause 30000 : ByteA = 0 : combocount = 0
lcdout 254,1
PortD.2 = 0
'endif
goto init ' Combination 78A5D


end

and it opened the gate with the push of any button, well almost, really it lied and said the gate was opening, and I have not had time to redress this issue.
I even played with another asm. code file emailed to me, that was fun learning how to use mpasm in windows, and editing the asm file without actual Knowledge of assembly, but I got it to compile and, you guessed it, it didn't work as expected either, just outputted a few strings all over the lcd. So here i am looking at the examples you and Steve have provided, thinking I will figure this out, likely not today
JS
edit1:Well I haven't learned all the lessons here, but the code works really well, Thanks!
edit2:Wow now I see how eprom works! Thanks again Darrel!
edit3: Thanks Steve for lookup table, now that makes sense too!
Just modified code to work as alarm console too, cool!

[Darrel Taylor]

Darrel, you said my code never went to gosub, . . . the if bytea != 0 then gosub combo, will not do it?

In the first post, that IF statement was After a GOTO statement. So it never gets executed. I see you've moved it in the latest version. But the rest ruined it.

I had actually addressed this problem earlier, then realized I was answering skimasks post instead of the original one. I guess I get to say it again.

First off, when you see a whole buch of IF statements one after the other, each one trying to catch a certain set of circumstances, it's probably the wrong way to do it. And this one is a prime example.

Let's say that the first keypress is a seven. The first IF statement works fine.

if ((ByteA = 7) and (combocount = 0)) then
    combocount = %00000001
    pause 1000
else
    combocount = 0
endif

It recognizes the first digit of the combination, and sets combocount to 1

Then it continues on to the next IF statement...

if ((ByteA = 8) and (combocount = %00000001)) then
    combocount = %00000011
    pause 1000
else
    combocount = 0
endif

At this point ByteA does not equal 8 (it's still 7), so it goes to the ELSE clause where it zero's combocount and starts everything from scratch again. It'll never recognize more than 1 digit.

Then after all the IF's are done, there's nothing to stop it from opening the gate, even though it only received 1 keypress.

But from the sound of it, it did exactly what you told it to.
<br>

[Leonardo]

Hello Joe,

It already works your I code?.

[mister_e]

@ Joe,

in your previous example, you should move your ISR or jump over

Init:    
    lcdout $FE,1
    LCDOUT 254,128,"AUTHORIZATION"
    LCDOUT 254,192,"REQUIRED TO OPEN"
    LCDOUT 254,153,"THIS GATE"
    LCDOUT 254,212,"KEY ENTRY CODE"

    '    ----> goto start:
 disable
KeypadINT:    
@ READKEYPAD _ByteA
    TRISB=%11110000
    PORTB=0
    INTCON.0=0
    resume
enable   
Start:

What happen here is that it meet a RESUME, which do something close to a RETURN. Having nothing is the stack, it jump somewhere you don't know and execute the code at the top again and again... and again...

[mister_e]

Leonardo, sorry i don't have Proteus, will be faster if you tell me wich PIC and how your keypad is attach to it.

[Archangel]

@ Joe,

in your previous example, you should move your ISR or jump over
[code]

Dough! . . . thanks Steve that does make sense. This project has been hugely successful, not only do I have working code now but more importantly I have learned enough to keep me busy understanding what I learned for weeks!
THANKS GUYS !

[mister_e]

sweet!

Pump up the volume...
<embed src="http://www.mister-e.org/Wav/yehaw.wav" autostart=false loop=false>

[Archangel]

Then it continues on to the next IF statement...

if ((ByteA = 8) and (combocount = %00000001)) then
    combocount = %00000011
    pause 1000
else
    combocount = 0
endif

At this point<b> ByteA does not equal 8 (it's still 7), so it goes to the ELSE clause where it zero's combocount and starts everything from scratch again.</b> It'll never recognize more than 1 digit.
<b>
Then after all the IF's are done, there's nothing to stop it from opening the gate, even though it only received 1 keypress.</b>

But from the sound of it, it did exactly what you told it to.
<br>

Is that because it has not gone back to the scan routine? Should I have used goto and resume or just put return after each if...then statement? I ask this <b>not </b>ignoring your statement I should not have done it this way in the first place.<br>
<b> Could you explain in more detail as to why? How does combocount get to the correct status to open the gate?</b>
<b>I really appreciate it Darrel.</b>
JS

[Darrel Taylor]

Is that because it has not gone back to the scan routine? Should I have used goto and resume or just put return after each if...then statement?

None of the above.
It's because it's the Wrong Logic for the job.

With an IF ELSE ENDIF, there are only 2 possibilities. True or False.
And that result is based entirely on 1 expression ... (ByteA = 7) and (combocount=0)

So essentially, you're asking it if the Whole combination is correct, by looking at just one keypress.

Then by stacking up 5 IF ELSE ENDIF's together, since they can't ALL be true at the same time, there will always be 4 of them saying the combination is Wrong.

Much like in real life, decisions aren't always as easy as True or False.
Usually, you'll have to consider several different things Before making a decision.
And those "things" may happen at different times, so you may not be able to make a decision until more information is available.

So instead of just the True or False, Black or White. Here's the answer.
You also need to be able to say "I don't know yet".

This is where just IF THEN is more useful.
Instead of only the 2 possibilities, IF THEN has Infinite possibilities.
Granted, It's either TRUE, or it's NOT, but by not taking action when it's not true, it's the same as saying "I don't know".

So now you can stack those up if you want, because they won't be interfering with each other by making their own decisions independently.
They only act on what they KNOW to be TRUE.

Here's what I mean...Still not the way I would do it, but for the sake of argument...

combo:
    IF (combocount = 0) and (ByteA = 7)   then GoodKey
    IF (combocount = 1) and (ByteA = 8)   then GoodKey
    IF (combocount = 2) and (ByteA = "A") then GoodKey
    IF (combocount = 3) and (ByteA = 5)   then GoodKey
    IF (combocount = 4) and (ByteA = "D") then GoodKey
    combocount = 0 ; invalid keypress
return

GoodKey:
    combocount = combocount + 1
    if combocount = 5 then GrantAccess
return

[Archangel]

None of the above.
It's because it's the Wrong Logic for the job.

With an IF ELSE ENDIF, there are only 2 possibilities. True or False.
And that result is based entirely on 1 expression ... (ByteA = 7) and (combocount=0)

So essentially, you're asking it if the Whole combination is correct, by looking at just one keypress.

Then by stacking up 5 IF ELSE ENDIF's together, since they can't ALL be true at the same time, there will always be 4 of them saying the combination is Wrong.

Much like in real life, decisions aren't always as easy as True or False.
Usually, you'll have to consider several different things Before making a decision.
And those "things" may happen at different times, so you may not be able to make a decision until more information is available.

So instead of just the True or False, Black or White. Here's the answer.
You also need to be able to say "I don't know yet".

This is where just IF THEN is more useful.
Instead of only the 2 possibilities, IF THEN has Infinite possibilities.
Granted, It's either TRUE, or it's NOT, but by not taking action when it's not true, it's the same as saying "I don't know".

So now you can stack those up if you want, because they won't be interfering with each other by making their own decisions independently.
They only act on what they KNOW to be TRUE.

Here's what I mean...Still not the way I would do it, but for the sake of argument...

combo:
    IF (combocount = 0) and (ByteA = 7)   then GoodKey
    IF (combocount = 1) and (ByteA = 8)   then GoodKey
    IF (combocount = 2) and (ByteA = "A") then GoodKey
    IF (combocount = 3) and (ByteA = 5)   then GoodKey
    IF (combocount = 4) and (ByteA = "D") then GoodKey
    combocount = 0 ; invalid keypress
return

GoodKey:
    combocount = combocount + 1
    if combocount = 5 then GrantAccess
return

I Get it, Thanks Darrel, then If you were inclined to code that way, would this be a place for select case? It seems as though the THEN Goodkey scenerio would make the combination work if out of sequence? Or would the loop cancel before combocount reaches 5 ? Oh your code works SWEET! Thanks Again.
Joe

[Darrel Taylor]

would this be a place for select case?

You could, but it just uses more code space. It's pretty much a Select Case the way the last example is shown. But here's a Select Case version...

combo:
    Select CASE combocount
        Case 0 : if ByteA = 7   then GoodKey
        Case 1 : if ByteA = 8   then GoodKey
        Case 2 : if ByteA = "A" then GoodKey
        Case 3 : if ByteA = 5   then GoodKey
        Case 4 : if ByteA = "D" then GoodKey
    END SELECT
    combocount = 0
return
    
GoodKey:
    combocount = combocount + 1
    if combocount = 5 then GrantAccess
return

Or, just to keep things nice and confusing, you could also do this...

Combo:
    Lookup  combocount,[7,8,"A",5,"D"], NextDigit
    if ByteA = NextDigit then 
        combocount = combocount + 1
        if combocount = 5 then GrantAccess
    else
        combocount = 0
    endif
return

It seems as though the THEN Goodkey scenerio would make the combination work if out of sequence?

Nope, that can't happen. You should run the program in MCSP debugger and watch what happens. After watching debuggers for awhile, you'll be able to see it in your mind, and programming will go a lot smoother. And eventually, you won't even need the debugger anymore, or the PIC. It'll run inside your head.

Oh your code works SWEET! Thanks Again.

No Problemo!

[Leonardo]

Hello to all,

I have followed east subject and it seems to me excellent, my english is not very good but treatment for understanding what you say.

This it is a interesting project, I am working to record the data in eeprom, when it has ready the code send.

[Archangel]

You should run the program in MCSP debugger and watch what happens. After watching debuggers for awhile, you'll be able to see it in your mind, and programming will go a lot smoother. And eventually, you won't even need the debugger anymore, or the PIC. It'll run inside your head.

I will have to make that purchase, as I have only the freebie version which was included with PBP, as you recommend it, it must be worthwhile.
Do you relize the power of this project? I am using it to operate the alarm on my mother's garage, another user here, for whom this was all about is using it for his gate, and it occured to me it is a useful tool to secure the table saw, bandsaw etc . . . from the children, or even adults! So since I do not have an address to send you some beer, i give you this, the knowledge that your efforts may save some little fingers.
JS