4x4 keypad Help

[aaliyah1]

Hi all
i am using a 18f452 with the 4 x4 keypad connected to portB
this is on the proton Development board and the connections are as the attachment below
All is get displayed on my lcd is

" Keypad Test "
"Press any key"
I have ran the program on micro studio ICD and the program seems to be struck
in this loop
==========================================
getkeyu:
' Wait for all keys up
PORTB = 0 ' All output pins low
TRISB = $f0 ' Bottom 4 pins out, top 4 pins in
If ((PORTB >> 4) != $f) Then getkeyu ' If any keys down, loop

Pause 50 ' Debounce
================================================== ====


Is there something i am missing
i have the complete code below and

================================================== ==============
DEFINE LOADER_USED 1 ' uses a bootloader

@ __CONFIG _CONFIG1H, _OSCS_OFF_1H & _HS_OSC_1H

Define OSC 20
clear

DEFINE LCD_DREG PORTD ' Use Portd for LCD Data
DEFINE LCD_DBIT 4 ' Use Upper(4) 4 bits of Port
' PORTD-4 thru PORTD-7 connects to
' LCD DB4 thru LCD DB-7 respectively
DEFINE LCD_RSREG PORTE ' PORTE for RegisterSelect (RS) bit
DEFINE LCD_RSBIT 0 ' PORTE-0 pin for LCD's RS line
DEFINE LCD_EREG PORTE ' PORTE for Enable (E) bit
DEFINE LCD_EBIT 1 ' PORTE-1 pin for LCD's E line

DEFINE LCD_BITS 4 ' Using 4-bit bus
DEFINE LCD_LINES 2 ' Using 2 line Display
DEFINE LCD_COMMANDUS 2000 ' Command Delay (uS)
DEFINE LCD_DATAUS 50 ' Data Delay (uS)

' ** Define LCD Control Constants **

I CON 254 ' Control Byte
Clr CON 1 ' Clear the display
Line1 CON 128 ' Point to beginning of line 1
Line2 CON 192 ' Point to beginning of line 2
Line3 CON 148 ' Point to beginning of line 3
Line4 CON 212 ' Point to beginning of line 4

'
' Initialise Hardware
' -------------------

TRISA=%00000000
TRISB=%00000000
TRISC=%10000000
TRISD=%00000000

INTCON2.7 = 1 ' Enable PORTB pullups
ADCON1 = 7 ' Make PORTA and PORTE digital
Low PORTE.2 ' LCD R/W low (write)

Pause 1000 ' Wait for LCD to start

lcdout I,Clr:Pause 30
lcdout I,Line1," Keypad TEST "
lcdout I,Line2,"..Power On.. !!"

' Define program variables
col var byte ' Keypad column
row var byte ' Keypad row
key var byte ' Key value



lcdout I,Clr:Pause 30
lcdout I,Line1," Keypad Test "
lcdout I,Line2, "Press any key" ' Display sign on message

loop: Gosub getkey ' Get a key from the keypad
lcdout I,Clr:Pause 30
lcdout I,Line3, #key
Pause 50
Goto loop ' Do it forever


' Subroutine to get a key from keypad
getkey:
Pause 50 ' Debounce

getkeyu:
' Wait for all keys up
PORTB = 0 ' All output pins low
TRISB = $f0 ' Bottom 4 pins out, top 4 pins in
If ((PORTB >> 4) != $f) Then getkeyu ' If any keys down, loop

Pause 50 ' Debounce

getkeyp:
' Wait for keypress
For col = 0 to 3 ' 4 columns in keypad
PORTB = 0 ' All output pins low
TRISB = (dcd col) ^ $ff ' Set one column pin to output
row = PORTB >> 4 ' Read row
If row != $f Then gotkey ' If any keydown, exit
Next col

Goto getkeyp ' No keys down, go look again

gotkey: ' Change row and column to key number 1 - 16
key = (col * 4) + (ncd (row ^ $f))
Return ' Subroutine over

End

Best Regards
Sabu

[mister_e]

Yes it will stuck, you need some pull-up resistors in that. You can enable the PIC internal one

INTCON2.7=0

Just saw you already did.. just the wrong way

AND you WILL have erratic results with this routine... add a PAUSEUS 5 in this section

TRISB = (dcd col) ^ $ff ' Set one column pin to output
PAUSEUS 5
row = PORTB >> 4 ' Read row

[aaliyah1]

Thank mister_e for your reply
i am a bit confused by what you mean by

just the wrong way

Also without doing anything else to the program apart from changing the Enable PORTB pullups line when i used a 16f877a

================================================== =
OPTION_REG.7 = 0 ' Enable PORTB pullups for 16f877a
'INTCON2.7 = 1 ' Enable PORTB pullups for 18f452
================================================== =

the program works fine could it be my pic?

Best Regards
Sabu

[mister_e]

In your first post you used...
INTCON2.7=1

But this actually DISABLE the internal pull-up...

Use
INTCON2.7=0
instead, and the problem will disapear

[aaliyah1]

Oops silly me
it works fine

thanks a lot

Sabu

[andymarrole]

i using pic18f4550 and PICBASIC PRO version 1.0 as my compiler..
while i compile my program below, there is warning which is

unable to include file keypad.bas
unable to include file lcd.bas..

this is my source code...

'****************************************************************
'*  Name    : UNTITLED.BAS                                      *
'*  Author  : [select VIEW...EDITOR OPTIONS]                    *
'*  Notice  : Copyright (c) 2010 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 10/5/2010                                         *
'*  Version : 1.0                                               *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************
Include "modedefs.bas" 

DEFINE PIC18F4550
DEFINE OSC 4


INCLUDE "KeyPad.bas" ' ( mister_e 's great keypad include file )
INCLUDE "lcd.bas"  
CMCON = 7
ADCON1 = 7
  
          
TRISD  = %00000000
TRISB  = %11111111
             
'// Declare Variables...
Col_A     VAR PORTB.0
Col_B     VAR PORTB.1
Col_C     VAR PORTB.2
Col_D     VAR PORTB.3
Row_A     VAR PORTB.4
Row_B     VAR PORTB.5
Row_C     VAR PORTB.6
Row_D     VAR PORTB.7



Scan_Col  VAR BYTE       ' Counter - current col  
Key_Press VAR BYTE       ' Value of key (0-9) & * + # + A + B + C + D
Key_Down  VAR BYTE       ' Flag set true when key is depressed
Allow_Key VAR BYTE       ' Flag - disallow multiple keys being pressed
I         VAR byte       ' General working var

Scan_Keypad:

  @ incf _Scan_Col, 1   ' Inc col pos...

  SELECT CASE Scan_Col  ' Col (1-4)
         
         CASE 1
              Col_A = 0 ' Switch on col (active low)    
              Col_B = 1 ' Col off    
              Col_C = 1 ' Col off 
          Col_D = 1 ' Col off
                       
              '// 1 Key
                       IF Row_A = 0 THEN        ' Key down? ... 
                          IF Allow_Key = 0 THEN ' Any other key down?
                             Key_Press = 1      ' Load var w/value of key           
                             Allow_Key = 1      ' Disallow other keys
                          ENDIF   
                       ENDIF                          
              '// 4 Key
                       IF Row_B = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 4                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// 7 Key
                       IF Row_C = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 7                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              

        '// * Key
                       IF Row_D = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 42                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              
         CASE 2
              Col_A = 1    
              Col_B = 0    
              Col_C = 1 
              Col_D = 1    
                       
              '// 2 Key
                       IF Row_A = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 2                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// 5 Key
                       IF Row_B = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 5                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// 8 Key 
                       IF Row_C = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 8                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// 0 Key
                       IF Row_D = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 0                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF

         CASE 3
              Col_A = 1     
              Col_B = 1     
              Col_C = 0
              Col_D = 1

              '// 3 Key
                       IF Row_A = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 3                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// 6 Key
                       IF Row_B = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 6                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
               '// 9 Key
                      IF Row_C = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 9                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// # Key
                       IF Row_D = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 35                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF


         CASE 4
              Col_A = 1     
              Col_B = 1     
              Col_C = 1
              Col_D = 0

              '// A Key
                       IF Row_A = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 65                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// B Key
                       IF Row_B = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 66                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
               '// C Key
                      IF Row_C = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 67                 
                             Allow_Key = 1
                          ENDIF   
                       ENDIF
              '// D Key
                       IF Row_D = 0 THEN
                          IF Allow_Key = 0 THEN 
                             Key_Press = 68                
                             Allow_Key = 1
                          ENDIF   
                       ENDIF


              Scan_Col = 0   
END SELECT


LCDOUT $fe,1
 LCDOUT " Key_Press "





'// Check for key release, all cols on (active low) ...
Col_A = 0     
Col_B = 0     
Col_C = 0
Col_D = 0

IF Row_A = 1 THEN
  IF Row_B = 1 THEN
     IF Row_C = 1 THEN
        IF Row_D = 1 THEN
           Allow_Key = 0
           Key_Down = 0
           Key_Press = 255
        ENDIF
     ENDIF
  ENDIF
ENDIF
           
GOTO Scan_Keypad

please help me...
thank you...