12F683, DT_INTs, and Lost pulses

[boroko]

Hi All,

Been fighting with unpredictable behavior on a project and need some fresh eyes.
Here is the minimal subset of the program that I'm fighting.
Without any pulses on the input, I get a steady output on the Heartbeat LED (HI in this case). As soon as there is a pulse on the input (1Hz-250Hz+), I get the heartbeat, and the LED showing entry into the INT handler. As soon as the input pulse goes to 0 again, everything stops.
Very puzzled...

'****************************************************************
'                          12F683   default 4MHz, running 8MHz
'                 ------------u-----------
'                -|vdd (+)         vss(-) |-         
'       LED out  -|gp5           p_a0/pgd |-  Pulse in       
'                -|p4/a4         p_a1/pgc |-  LED2 out       
'                -|p3/Vpp/MCLR  p_a2/ccp1 |-       
'                 ------------------------    
'****************************************************************
#CONFIG
   __config _INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF
;   __config _FOSC_INTOSCIO & _WDT_ON & _MCLRE_OFF & _CP_OFF
#ENDCONFIG
INCLUDE "DT_INTS-14.pbp"    ; Base Interrupt System. Ver 1.10
INCLUDE "ReEnterPBP.pbp"    ; Include for DT_INTS.  ver 3.4
'***************************************************************************
define OSC 8            ' tell compiler that OSC is 8MHz
IN          var GPIO.0  ' monitor Input pulse 
LED2        var GPIO.1  ' INT function  LED
LED         var GPIO.5  ' Heartbeat LED  
Cnt         var word    ' word var for TMR1 high and low bytes
PulseFlag   var byte    ' 
                        
OSCCON = %01110000      ' 8MHz instead of 4MHz
'INTCON = %11001000      ' GIE,PEIE:ON, T0IE,INTE:OFF, GPIE:ON, TOIF,INTF,GPIF:CLEAR
IOC    = %00000001      ' Enable IOC on GPIO0 to capture pulse
T1CON  = %00000001      ' TMR1 prescale=1:1 clock=Fosc/4, TMR1=on
GPIO   = %00001001      ' Outputs (except 0&3) = 0 on bootup
OPTION_REG = %00000110  ' ind pull-ups, int clk,Tmr0=1:(111=256, 110=128)
TRISIO = %00001001      ' Pins output(except 0&3)                                  
CMCON0 = %00001111      ' Comparator off. NEEDED to avoid RWM problem
ANSEL  = %00000000      ' Set all digital 
;----[Interrupts]----------------------------------------
ASM
INT_LIST  macro    ; IntSource,   Label,   Type, ResetFlag?
        INT_Handler   GPC_INT,   _Capture,  PBP,  yes
    endm
    INT_CREATE              ; Creates the High Priority interrupt processor
    INT_ENABLE  GPC_INT     ; enable Capture interrupts
ENDASM

Main: 
  toggle LED            ' heartbeat
  pause 10   
  if PulseFlag then
    toggle LED2
    PulseFlag = 0
   endif 
GOTO Main
'---[IOC - interrupt handler]------------------------------------------
Capture:  ' Enter here with Pulse (IOC) 
PulseFlag = 1           ' Caught a pulse
Cnt.highbyte = TMR1H    ' grab TMR1
Cnt.lowbyte = TMR1L     ' Cnt stays the same until the next pulse.
    T1CON.0=0           ' Turn TMR1 off
    TMR1H = 0           ' clear TMR1 
    TMR1L = 0           ' 
    T1CON.0=1           ' Turn TMR1 on
    PIR1.0 = 0          ' Clear TMR1IF. 
@ INT_RETURN

END

I hope the code is reasonably self explanatory.
Thanks for any observations.
bo

[richard]

you cannot clear the gpio change flag until you read the gpio port

Capture:  ' Enter here with Pulse (IOC) 
PulseFlag = 1           ' Caught a pulse
Cnt.highbyte = TMR1H    ' grab TMR1
Cnt.lowbyte = TMR1L     ' Cnt stays the same until the next pulse.
    T1CON.0=0           ' Turn TMR1 off
    TMR1H = 0           ' clear TMR1 
    TMR1L = 0           ' 
    T1CON.0=1           ' Turn TMR1 on
    PIR1.0 = 0          ' Clear TMR1IF. 
    tmp=gpio.0
    
@ INT_RETURN

[boroko]

(beating head against wall) Thank you Richard. For the life of me, I couldn't see that. Saw your reply, and DUH, of course.
I appreciate the help.

bo

[Fujimanme]

Hello Bo,

Were you able to get your 12F683 working? I am also using a 12F683 for a remote pressure sensor application but I am unable to compile the code as I get the interrupt error.

ERROR: Variable wsave2 position request 288 beyon RAM_END 191.

I have edited the DT_INTS-14.bas and left the wsave $20 and wsave $A0 enable, but alas still no go.

I know my setup is OK because if I grab an older code I was playing with years ago with DT Interrupts for 16F648A, it successfully compiles without any issues and I can program it to the PIC...

Cheers
Attila

[boroko]

I have been working on the bigger chips for this project to get some other features. I'm going back to the 12F683 to use what I learned. If I get an answer, I'll let you know.

Is it the INT on change that you are trying to use?

bo