Problem with external interrupts (B0-B2) on 18f452

[cncmachineguy]

Hi Tom, I hope you don't mind I am posting your code from the first post so its easier for folks to see. Plus it just makes it easier for me to look at your results and follow the code.

DEFINE LOADER_USED 1
DEFINE USE_LFSR 1
Include "modedefs.bas"     'this is required for RS232 comms
ADCON1=7
' Assign variable names
DBGDSPL     VAR PORTB.5      'Debug display port
CurrPuls    var byte
PulseA      var word
PulseB      var word
PulseR      var word
LastACnt    Var word
LastBCnt    Var word
LastRCnt    var word
CurrSec     var word
LastSec     var word
IntCount    var word                    
pause 10
trisb=%00000111
T0CON = %10000011       'Define Timer0 - 1:16
RCON.7 = 0
INTCON = %10110000      'Enable TMR0 & Pin B0-B2 interrupts 
INTCON2= %10000000      'Falling Edge
INTCON3= %11011000
goto start
'---------------------------------------------------------Interrupt Code
Disable                 ' No interrupts past this point
myint:
if INTCON.1<>0 or INTCON3.0<>0 or INTCON3.1<>0 then    'Pulse Interrupt
    IntCount=IntCount+1
    if INTCON3.0=1 and INTCON.1=0 and INTCON3.1=0 then PulseA =PulseA +1
    if INTCON3.0=0 and INTCON.1=1 and INTCON3.1=0 then PulseR =PulseR +1
    if INTCON3.0=0 and INTCON.1=0 and INTCON3.1=1 then PulseB =PulseB +1
 
    SerOut DbgDspl, N9600, [$1b,$2a,$80]        'turn on background lighting of debug display
    SerOut DbgDspl, N9600, [$1b,$30]
    SerOut DbgDspl, N9600, ["I:",#IntCount, " A:", #INTCON3.0, " R:", #INTCON.1, " B:", #INTCON3.1]
    SerOut DbgDspl, N9600, [$1b,$32]
    SerOut DbgDspl, N9600, ["A:", #PulseA, "R:", #PulseR, "B:", #PulseB, "S:", #CurrSec]
    INTCON.1=0 : INTCON3.0=0 : INTCON3.1=0
endif
if INTCON.2=1 then              'timer overflow interrupt
    CurrSec = CurrSec +1
    TMR0H=11 : TMR0L=186        'set tmr0 cycle count to 3002 so overflows in 1.0 sec
    'TMR0H=231 : TMR0L=147      'set tmr0 cycle count to 59283 so overflows in .1 sec
    'TMR0H=253 : TMR0L=143      'set tmr0 cycle count to 64911 so overflows in .01 sec
    INTCON.2 = 0
endif
Resume                  ' Return to where interrupt occured
Enable                   
'---------------------------------------------------------End of Interrupt code
Start:
PulseA=0 : PulseB=0 : PulseR=0 : CurrSec=0 : LastSec=0 : IntCount=0
LastACnt=0 : LastRCnt=0 : LastBCnt=0
SerOut DbgDspl, N9600, [$1b,$2a,$80]        'turn on background lighting of debug display
SerOut DbgDspl, N9600, [$1b,$30]
SerOut DbgDspl, N9600, ["Start "]
SerOut DbgDspl, N9600, [$1b,$32]
pause 10
 
On Interrupt Goto myint ' Define interrupt handler
Mainloop:
    if PulseR<>LastRCnt or PulseA<>LastACnt or PulseB<>LastBCnt or CurrSec<>LastSec then
'    SerOut DbgDspl, N9600, [$1b,$2a,$80]        'turn on background lighting of debug display
'    SerOut DbgDspl, N9600, [$1b,$30]
'    SerOut DbgDspl, N9600, ["I:",#IntCount, " A:", #INTCON3.0, " R:", #INTCON.1, " B:", #INTCON3.1]
'    SerOut DbgDspl, N9600, [$1b,$32]
'    SerOut DbgDspl, N9600, ["A:", #PulseA, "R:", #PulseR, "B:", #PulseB, "S:", #CurrSec]
    endif
    pauseus 1
GOTO Mainloop
end

My time estimate is based soley on the serout stuff. I was just taking a guess at the number of bytes sent at 9600 baud.


As for DT_INT, search it on this forum and you will find tons of help. I am not so good at finding and posting the links or I would. Basically it is an awesome include to handle all your interrupt needs. It gives you true interrupts as if you had ASM interrupt, but without the hassle. With on interrupt, the problem is you are limited to only seeing the INT after each PBP instruction. So for code with a pause for instance, the interrupt won't fire until after the pause is done.