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arduinoatmegaforth

Execute FlashForth word when pin changes

I have a word that I wish to trigger on pin change:

: example
  ." Hello, world! "
;i

I am using External Interrupt Request 1, which is interrupt vector no. 3 according to page 65 of the datasheet and this diagram I use.

' example 3 int!
ei

When I try to change the value of a pin (pin 3 in this case), nothing happens.

Am I doing something wrong?

Solution

  • There are several things wrong with the code I posted above, but I did get it working after looking at other examples and reading the data sheet:

    \ Pin Change Interrupt 0
4 constant pcint0

\ Pin Change Mask Register 0
$6b constant pcmsk0

\ Pin Change Interrupt Control Register
$68 constant pcicr

ram variable example

: example+1
  1 example +!
;i

: int-enable
  ['] example+1 pcint0 int!
  ei
;

int-enable

%00000001 pcmsk0 mset
%00000111 $68 mset

\ Shorting pin 8 will now increment `example` variable.