Interruption

[Art]

Thought I already did.
It's using hardware to do what should and can be done in software.
Like wiring a circuit to turn the pic's power off to turn an LED off.
and developing bad habit at the same time, and not learning anything.

[mackrackit]

Well after you made an edit to your post you have some explanation.

Looping back through the code every so often to check on a button smells like some sort of pasta to me.

Maybe the OP should learn to use the hardware. Then when the code grow to more than a few lines......

Wait a minute. Your joking, right?
Using an interrupt is forming bad habits.
Now I get it.
NOT!

[Art]

When it's not needed, I think it is.
What if the platform didn't support interrupts?
I think using an interrupt when it isn't needed is forming a bad habit.
The loop is happening anyway, and I have one less label in my code.
It's less spaghetti than the original which doesn't run in one single loop.
An interrupt would add more spaghetti in the generated asm to goto 0x04.

This is a simple program, but as it grew, you might need an interrupt for something else.

EDIT; ps I edited to edit the program, but haven't actually run it.
if it has any issue, it still offers a solution.

[mackrackit]

Fair enough.

Good to see all possible solutions and reasons for the solutions.

[Bruce]

I'll give it a shot with a simple ON INTERRUPT version.

  x var BYTE
  Switch VAR BIT
  
  TRISA = $FF
  TRISC = 0

  ANSEL = 0            ' A/D disabled (all digital)
  ANSELH = 0
  IOCA.3 = 1           ' int-on-change enabled for RA3
  INTCON = %10001000   ' enable global & int-on-change interrupts

  Switch = 1

  ON INTERRUPT GOTO MyISR
  
mainloop:
  x = 1
  
loops:
  PORTC = x
  pause 500
  if switch = 1 then
     if x == 8 then 
        goto mainloop
     else
        x = x << 1
        goto loops
     endif
  else
    if x == 1 then
       x = 8
       goto loops
    else
       x = x >> 1
      goto loops
    endif
  endif
  GOTO mainloop ' just in case

  DISABLE
MyISR:
  WHILE PORTA.3=0  ' wait for button release (so we can clear the int flag & be
  WEND             ' sure it interrupts on a high-to-low transition)

  Switch = ~Switch ' toggle Switch
  INTCON.0 = 0     ' clear interrupt flag bit
  RESUME
  
  END

There must be ten gozillion ways to do something like this, even without an interrupt, but
it's still handy to at least learn about interrupts.

Note that you could also do something similar by just monitoring the interrupt flag-bit with
global interrupts disabled. You just need to get a tad more creative...;o}

Tap & release the button as fast as you can to see how quickly it reacts.