Electro Tech forum,
Thanks to help I've gotten on this forum I now have change-
state interrupts working on my 16f88. I started out using
PORTB.4 with a 10K pullup. Worked fine.
Since I need 2 change-state interrupts I tried using PORTB.5
along with PORTB.4 but when I put a pullup on PORTB.5,
PORTB.4 no longer causes an interrupt.
PORTB 5, 6 & 7 all work together or separately but PORTB.4
will not work if there is a pullup on PORTB.5.
I've tried 2 different 16f88's with the same results.
I couldn't find anything about this in the datasheet so
there must be something I don't know about this hardware.
I'm OK using RB5 and RB6 for now but I would like to
know what's going on for future use.
Here's my PORTB configuration code when using PORTB<7:4>
'configure port b for hardware spi and hardware interupts
TRISB = %11110001 'portb 0,4,5,6,7 are input
SSPCON = %00100000 'Synchronous Serial Port Enable bit
INTCON = %10010000 'Enable external interrupts
OPTION_REG = %10000000 'Turn off pull-up resistors, falling edge on RB0
Thanks for any reply,
jerryd
Thanks to help I've gotten on this forum I now have change-
state interrupts working on my 16f88. I started out using
PORTB.4 with a 10K pullup. Worked fine.
Since I need 2 change-state interrupts I tried using PORTB.5
along with PORTB.4 but when I put a pullup on PORTB.5,
PORTB.4 no longer causes an interrupt.
PORTB 5, 6 & 7 all work together or separately but PORTB.4
will not work if there is a pullup on PORTB.5.
I've tried 2 different 16f88's with the same results.
I couldn't find anything about this in the datasheet so
there must be something I don't know about this hardware.
I'm OK using RB5 and RB6 for now but I would like to
know what's going on for future use.
Here's my PORTB configuration code when using PORTB<7:4>
'configure port b for hardware spi and hardware interupts
TRISB = %11110001 'portb 0,4,5,6,7 are input
SSPCON = %00100000 'Synchronous Serial Port Enable bit
INTCON = %10010000 'Enable external interrupts
OPTION_REG = %10000000 'Turn off pull-up resistors, falling edge on RB0
Thanks for any reply,
jerryd