PortB Change Interrupts

[backstabber]

I have setup my code to get an interrupt when PortB's Pin 1 or Pin 0 gets triggered. I am using DT's Instant Interrupt and I have created and enabled interrupt processor for RBC_INT. The interrupt routine is called when either one of the pin is triggered (contact closure), however I can't tell exactly which pin was triggered. I am doing something like this:

TRIGGER0 VAR BIT
TRIGGER1 VAR BIT

TRIGGER0 = portb.0
TRIGGER1 = portb.1

However, both would read 1. Any idea what I am doing wrong?

Any help would be greatly appreciated.

P.S. I am a picBasic novice. Please go easy on me.

[krohtech]

What pic are you using?

[krohtech]

If I am reading the data sheet correctly, the "input change Interrupts" will fire when anything on the port changes. I do not believe the individual pins can be monitored this way. If you need individual pins you may need to use an "external interrupt" and INT_INT.

Darrel please correct me if I am wrong

[backstabber]

What pic are you using?

I am using 18F66J15

[Darrel Taylor]

RBC_INT only triggers on chages with PORTB<7:4>

For PORTB.0, you would use INT0_INT
PORTB.1 is INT1_INT

Each one should have it's own handler, so it automatically knows which pin triggered.
<br>

[backstabber]

RBC_INT only triggers on chages with PORTB<7:4>

For PORTB.0, you would use INT0_INT
PORTB.1 is INT1_INT

Each one should have it's own handler, so it automatically knows which pin triggered.
<br>

Actually, I meant to read from pin 4 and 5. That solves half of the problem.

I have corrected that in my code, still same problem.

[Darrel Taylor]

Keep in mind that any changes on PORTB.6 or 7 will also trigger an interrupt. It's best to Not Use 6 and 7 for anything else.

Old_Bits VAR BYTE
New_Bits VAR BYTE

INCLUDE "DT_INTS-18.bas"        ' Base Interrupt System
INCLUDE "ReEnterPBP-18.bas"     ' Include if using PBP interrupts

ASM
INT_LIST  macro    ; IntSource,         Label,  Type, ResetFlag?
        INT_Handler    RBC_INT,  _RBC_handler,   PBP,  yes
    endm
    INT_CREATE               ; Creates the interrupt processor
ENDASM

Old_Bits = PORTB
@    INT_ENABLE   RBC_INT     ;RB Port Change Interrupt

Main:
  Pause 1000
GOTO Main

'---[RBC - interrupt handler]---------------------------------------------------
RBC_handler:
    New_Bits = PORTB
    IF (New_Bits.4 <> Old_Bits.4) THEN
        ; -- PORTB.4 has changed -- 
    ENDIF
    IF (New_Bits.5 <> Old_Bits.5) THEN
        ; -- PORTB.5 has changed -- 
    ENDIF
    Old_Bits = New_Bits
@ INT_RETURN

[jellis00]

RBC_INT only triggers on chages with PORTB<7:4>
<br>

Darrel, I know this statement was related to a posting for a 18F66J15, but I am trying to use RBC_INT for PortB.2 and PortB.3 on a 16F886. I had a design going on a 18F2550 that used INT2_INT on PortB2 and worked well. However, for reasons I won't go into here I had to move the design to a 16F886 and continue to use PortB.2 and PortB.3 as interrupt inputs from the alarm pins on a DS1337 RTC. I already have PCBs built originally for the 28-pin 18F2550 and am trying to salvage them without trace changes by substituting a 28-pin 16F886 on the same board layout. My question...is there anyway I can use RBC_INT on the PortB.2 and PortB.3 pins of a 16F886 and monitor which pin actually received the interrupt? I have noted your OLDPORT vs NEWPORT technique to do this kind of interrupt isolation and presume I can do this on my 16F886 if RBC_INT will work ont these ports? Can you help me out here?

[Darrel Taylor]

John,

On the 16F88x's use IOC_INT (Interrupt On Change).

Set the pins you want to monitor in the IOCB register.