Push button issue

[Jacques Nilo]

Hi again GCBasicers !
I run into a problem with the following code. I never get out the Do while Button = On ... Loop even when I release the push button. But I do enter the sub OK when I push the button.
And the same program without the Sub works ok (see below...)
Any ideas ?
Thanks

;Chip Settings
#chip 16F690, 8
#config FOSC_INTOSC, WDTE_OFF

;Defines (Constants)
#define LCD_IO 4
#define LCD_RS PORTC.5
#define LCD_NO_RW
#define LCD_Enable PORTC.4
#define LCD_DB4 PORTC.0
#define LCD_DB5 PORTC.1
#define LCD_DB6 PORTC.2
#define LCD_DB7 PORTC.3

#define Red_button      porta.0         ;Set red pushbutton
#define White_button    porta.1         ;Set white pushbutton

Dir Red_button   In
Dir White_button In

Sub Test_button(Button)
  If Button = On Then
    ButtonCount = 0
    Do While Button = On
      Wait 10 ms
      ButtonCount += 1
    Loop
    If ButtonCount > 5  then           'Debounce
      cls
      if ButtonCount > 50 then         'Long push
         print "Long push"
      else                             'Short push
         print "Short push"
      end if
    end if
    wait 1 s
  End if
end sub

do
 Test_button(White_button)
loop

The same program without the sub works perfectly well:

;Chip Settings
#chip 16F690, 8
#config FOSC_INTOSC, WDTE_OFF

;Defines (Constants)
#define LCD_IO 4
#define LCD_RS PORTC.5
#define LCD_NO_RW
#define LCD_Enable PORTC.4
#define LCD_DB4 PORTC.0
#define LCD_DB5 PORTC.1
#define LCD_DB6 PORTC.2
#define LCD_DB7 PORTC.3

#define Red_button      porta.0         ;Set red pushbutton
#define White_button    porta.1         ;Set white pushbutton

Dir Red_button   In
Dir White_button In

DO
  If White_button = On Then
    ButtonCount = 0
    Do While White_Button = On
      wait 10 ms
      ButtonCount += 1
    Loop
    If ButtonCount > 5  then           'Debounce
      cls
      if ButtonCount > 50 then         'Long push
         locate 0,0
         print "Long push"
         locate 1,0
         print ButtonCount
      else                             'Short push
         locate 0,0
         print "Short push"
         locate 1,0
         print ButtonCount
      end if
    end if
    wait 1 s
    cls
  End if
loop

[William Roth]

Hi Jacques,

A constant such as a pin name cannot be passed to a SUB, so use MACRO instead.

Replace the SUB with this MACRO and test.

~~~~
Macro Test_button (Button)
if Button = ON then
wait 10 ms 'debounce
ButtonCount = 0

       Do While Button = On
           Wait 10 ms
           ButtonCount += 1
       Loop

       if ButtonCount > 5  then
           if ButtonCount > 50 then   'Long push
               print "Long push"
           else                       'Short push
               print "Short push"
           end if
       end if
       wait 1 s
   end if

End Macro
~~~~~

[Jacques Nilo]

Hi Bill,
Thanks for the trick. It does work perfectly!
To Anobium: what about mentioning that restriction (quite logical after all) in the Subroutines parameter help chapter ?
Jacques

[Anobium]

@Jacques. I will - a good idea.

Also, have a search in the Help File for TOGGLE. This shows the method to pass port parameters to a sub routine.

[Jacques Nilo]

[Jacques Nilo]

Hello all!
I did my homework:-). I found an interesting thread about passing objects to functions and also read the PEEK command help file. Following the Toggle approach suggested by Anobium I have adjusted the code as follows. It uses the PEEK command and the @ parameter.
As far as the comparison with the Macro approach is concerned it looks like it boils down to a trade off between portability and size. The macro approach will duplicate n times the asm code if the macro is called n times with n different calling arguments. The PEEK approach is PIC dependant since you have to pass the destination bit adress as an argument.
Jacques

;Chip Settings
#chip 16F690, 8
#config FOSC_INTOSC, WDTE_OFF

;Defines (Constants)
#define LCD_IO 4
#define LCD_RS PORTC.5
#define LCD_NO_RW
#define LCD_Enable PORTC.4
#define LCD_DB4 PORTC.0
#define LCD_DB5 PORTC.1
#define LCD_DB6 PORTC.2
#define LCD_DB7 PORTC.3

Dir PORTA.0 In
Dir PORTA.1 In
Dir PORTB.4 In

Sub Test_button(in DestPort as word, in DestBit)
  If (PEEK(DestPort) and DestBit) = DestBit Then            
    wait 10 ms
    ButtonCount = 0
    Do While (PEEK(DestPort) and DestBit) = DestBit
      wait 10 ms
      ButtonCount += 1
    Loop
    if ButtonCount > 50 then         'Long push
      print "Long push"
    else                             'Short push
      print "Short push"
    end if
    wait 1 s
    cls
  End if
end Sub

do

;PORTA.0/RA0 located on bit 0 of PORTA register (Table 2.1 of 16F690 datasheet)
;If on then PORTA=00000001 i.e. 1 in decimal

  Test_button(@PORTA,1)           'Check status of PORTA.0

;PORTA.1/RA1 located on bit 1 of PORTA register (Table 2.1 of 16F690 datasheet)
;If on then PORTA=00000010 i.e. 2 in decimal

  Test_button(@PORTA,2)           'Check status of PORTA.1

;PORTB.4/RB4 located on bit 4 of PORTB register (Table 2.1 of 16F690 datasheet)
;If on then PORTB=00010000 i.e. 16 in decimal

  Test_button(@PORTB,16)          'Check status of PORTB.4

loop