keypad 4x3

[EarlyBird2]

Jonas2

And it still does not work?

[jonas2]

not yet, and the keys are shifted

[EarlyBird2]

You are using pull up resistors for the inputs so col will be 1111 when no key pressed. If you press number 1 then it will be 1011 so at ****2 1011 xor 1111 will become 0100 and key=(0*3)+(NCD(0100))

which is 3 and on your lookup the third number is 7 so change the 7 to 1 and that one will be correct.

If you wire

'------RB4--RB5--RB6--
' | | |
'RB0----1----2----3---row1
' | | |
'RB1----4----5----6---row2
' | | |
'RB2----7----8----9---row3
' | | |
'RB3----*----0----#---row4
' | | |
'-----col1--col2--col3

then

the lookup table is

LOOKUP key,["123456789*0#"],skey which is a bit neater.

If you press number 1 then it will be 1110 so at ***2 1110 xor 1111 will become 0001 and key=(0*3)+(NCD(0001))which is 1 and on your lookup the first number is 1 so that one is correct.


Lets try again with number 8 now we have 1101 which becomes 0010 and key=(2*3)+(NCD(0010))which is 8 and on your lookup the eighth number is 8that one is correct.

so these are the changes to make

col = PORTB >> 4 ' Read columns ****** ************** 1
IF col != $f THEN gotkey ' If any keydown, exit
NEXT row
GOTO getkeyp ' No keys down, go look again

gotkey: ' Change row and column to key number 1 – 16

key = (row * 3) + (NCD (col ^ $f)) ******************** 2




'------RB4--RB5--RB6--
' | | |
'RB0----1----2----3---row1
' | | |
'RB1----4----5----6---row2
' | | |
'RB2----7----8----9---row3
' | | |
'RB3----*----0----#---row4
' | | |
'-----col1--col2--col3


'LOOKUP key,["1","4","7","*","2","5","8","0","3","6","9","# "],skey

LOOKUP key,["123456789*0#"],skey ******************** 3

Do you understand the maths and logic now? XOR always intrigued me along with bitwise operators. Why did anyone even think of this was my first thought. After a while I have found them useful.

Steve

[jonas2]

Hello

I still have not solved my problem, I tried different configuration
and impossible to get what I want?

Do you have other examples of management programs 4x3 keypad.

Thank you

[aratti]

Do you have other examples of management programs 4x3 keypad.

Why don't you use the universal keypad project? See it @ http://www.picbasic.co.uk/forum/showthread.php?t=10420

Al.

[EarlyBird2]

In your program you have the rows and columns the wrong way round and also can we resolve wether it is a 3x4 or 4x4 keypad because in your program you have 16 digits in your lookup table.

It looks to me as if you have not read my last post?

Steve

[jonas2]

Hello EarlyBird2

Thank you for your help and it works well.

[EarlyBird2]

You are most welcome.

Steve