Interruption

[ciroman]

Hello everyone, again!

This time I'm wondering if there is any way to have an event(like a button press) interrupt the code and go to a line label at any time?

The problem with my code is that the controller only checks for the button press after that pause. That pretty much means that you have to hold down the button to get the right timing in order for the moving LEDs to switch direction(which is what my code is about). So is there any way to interrupt the program at ANY time and then point it at a line label to continue there?

this is my code:

x var byte
switch var bit
TRISA = 1
TRISC = 0
switch = 1

mainloop:
x = 1
loop:
PORTC = x
pause 500
if switch = 1 then
	if PORTA.3 = 0 then
		switch = ~switch
		goto loop
	endif
	if x == 8 then 
		goto mainloop
	else
		x = x << 1
		goto loop
	endif
else
	if PORTA.3 = 0 then
		switch = ~switch
		goto loop
	endif
	if x == 1 then
		x = 8
		goto loop
	else
		x = x >> 1
		goto loop
	endif
endif

[mackrackit]

Look at interrupt on change normally on PORTB.

[ciroman]

We'll I've got a premade board - The PICKit 2 so the button is on the PORTA.3 pin - just like in the program. Is there no way to do it with that pin?

[mackrackit]

Check the data sheet and see what that pin can do. If it has ADC then with some imagination you could do an ADC interrupt.
But just change things around to use an interrupt pin. That is what they are for.

[Acetronics2]

Hi,

My crystal ball says ...

" Pickit2 with a ready made demo card means a 16F690 " ...

RA.3 shows an Interrupt on change feature ...

soooo ... just use it !!!

Alain

PS: try to give SOME MORE INFOS if you have further questions ...

[Art]

An interrupt is overkill for this, and not the typical way to handle the problem at all.
I'd use a counter to have your button checked every 10ms, and LED routine run every 500ms like this.
and you get to save the interrupt for when it's actually needed.

x var byte
direction var bit
timerbyte var byte
TRISA = 1
TRISC = 0
x = 1

loop:
PORTC = x
pause 10
timerbyte = timerbyte + 1

IF PORTA.3 = 0 then
IF direction = 0 THEN
direction = 1
ELSE
direction = 0
ENDIF ' direction
ENDIF ' button

IF timerbyte = 50 THEN timerbyte = 0 ' 500ms has passed if timerbyte = 0

IF timerbyte = 0 THEN
IF direction = 0 THEN
	IF x = 8 THEN x = 1
	x = x << 1
ELSE
	IF x = 1 THEN x = 8
	x = x >> 1
ENDIF ' direction
ENDIF ' timerbyte

goto loop