Newbie - 16F628A and switch latching

[malc-c]

Yeah, I think I might have a go at the BUTTON statement...

Let me go away and RTFM first, have a play, try and get something together before bailing be out

Before I start though, any comments on configuring PORTA (inc MCLR) for in/outputs ??

Malc

[Acetronics2]

Here a cutout ...

PORTA = 0 ' declare port level BEFORE port direction = safe power-on

PORTB = 0

'Pour 16F628

CMCON = 7 ' PortA Digital inputs
CCP1CON = 0 ' PWM off

' DATA @1,word 625,0,word 545,word 750 ' pre-setting EEPROM


'************************************************* *****************************
' Initialisation commutation : Vérification batterie
'************************************************* *****************************

init:
battok = 1 ' setting critical variables ...
dejavu = 0
bougie = 0
error = 0
Servo = 0
TRISA = %00000011 ' Port Direction
TRISB = %00000001

Pause 400 ' Stabilisation au branchement

GoSub verbatt ' beginning of real program ...batt testing i.e.


Cheers

Alain

[malc-c]

Ok, trying to get my head round the BUTTON statement, and failing.. bu I just love the line

In general, it is easier to simply read the state of the pin in an IF..THEN
than to use the BUTTON command as follows:
If PORTB.2 = 1 Then notpressed

which was what I was originally doing .....

Oh well ... I'll keep trying

[malc-c]

Ok after a lot of tries I finally have something that works. Here's the centre section of the code with the initialisation parts ommited for clarity

LED1 var  PORTB.4       'LED1 (green) on pin 10 (RB4)
LED2 var  PORTB.5       'LED1 (red) on pin 11 (RB5)

SW0 var PORTB.0          'switch input pin 6 (RB0)
SW1 var PORTB.1          'switch input pin 7 (RB1)

SWFLAG1 var Byte      ' counter for track 1

Swset1 var bit
Swset2 var bit

low led1
low led2 
               
Swset1=0 
Swset2=0
             
SWFLAG1=0

Main:

if SWFLAG1 >2 then     ' if the counter is >2 then reset all
    swset1=0
    swset2=0
    SWFLAG1=0
endif

If SW0=0 Then
swflag1 = swflag1 +1  ' increase count by 1
swset1=1
pause 500
endif

If SW1=0 Then 
swflag1 = swflag1 +1  'increase count by 1
swset2=1
pause 500
endif

if swset1=1 then
high led1                'then turn on RB4 (and hence the LED)
else
low led1                 'else, LED is off
endif

If Swset2=1 then       
high led2                'then turn on RB5 (and hence the LED)
else
low led2                 'else, LED is off
endif

Basically rather than try and compare a condition of swset1 and swset2 and SW0, I simply used SWFLAG1 as a counter to count the number of times the switches are activated, and if it is greater than 2 reset the couter and swset 1 and 2 to 0.

Now when sw0 goes low for the first time SWFLAG1 is = 1, when sw1 goes low SWFLAG1 =2 then when the loco is placed at the front of the train andis driven over SW0 for the second time SWFLAG1 =3. As the "IF SWFLAG1 > 2" condition is reached, SWFLAG1 is reset to 0, as is swset1 and swset2.

Now just have to replicate this for the other 6 inputs and outputs

I know this may seem trivial to the more experienced programmers, but its my first real program with PBP that is beyond the simple flash a LED, and I'm really pleased that I managed to figure something out, after some guidance from you guys here.

Thanks

Malcolm

Oh, and seeing that I RTFM and did my homework... do I qualify for a dozen lashes form Mel (alias Ms Whippy )

[Acetronics2]

Ok, trying to get my head round the BUTTON statement, and failing.. bu I just love the line



which was what I was originally doing .....

Oh well ... I'll keep trying

Hi,Malc

The IF THEN Statement implies your switch is an ideal switch and debouncing not tricky ...

BUTTON is more complicated and slow ... but works in very difficult situations.

The state of art is to verify the button has not changed its state BEFORE debouncing time has ended ...
Multiple IF ... THEN ... ELSE following each others reach that GOAL ...

Alain