Zero Crossing Concept Using Optocoupler, GPIO Change Int, and DT's Instant Interrupt

' This code can only be compiled with the file named "DT_INTS-14_MOD.bas".
'The file has some additions to DT's original file for GPIO change interrupt.

'===12F683======
@ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_ON & _FCMEN_OFF & _IESO_OFF & _PWRTE_OFF

CLEAR 
OSCCON =%01110001 ' Internal 8MHz osc.
DEFINE OSC 8

CMCON0 =7	        ' Disable analog comparator
TRISIO =%00001000
GPIO   =0 
ADCON0 =0
ANSEL  =0          ' All digital.
CCP1CON=0

'=======================
ZeroLine  VAR GPIO.3  ' Input for zero crossing.
Out	    VAR	GPIO.5  ' Output pin.
CountVal VAR WORD   ' A variable to count incoming 50Hz pulses.

' Include files for DT's interupt routines.
INCLUDE "DT_INTS-14_MOD.bas"     ; Base Interrupt System ; Attention ! Modified file !
INCLUDE "ReEnterPBP.bas"         ; Include if using PBP interrupts

PAUSE 20

ASM
INT_LIST  macro                ; IntSource,   Label,  Type, ResetFlag?
        INT_Handler     GPIF_INT,  _KES,   PBP,  yes
    endm
    INT_CREATE                ; Creates the interrupt processor
ENDASM
                    
IOC.3 = 1	                  ; Enable interrupt on GP3 change (change this pin to the one you need).

@   INT_ENABLE   GPIF_INT     ; enable GPIO Change (INT) interrupts
    

Begin:
    CountVal=0


Start: 

' Here, lets have a simple program just to test the zero cross pulses.
   SELECT CASE CountVal
   
        CASE IS > 200           ' Counter resets.
               CountVal=0 
        CASE IS > 100           ' Output is OFF.    
              Out=0
        CASE IS > 50            ' Output is ON.
              Out=1
    END SELECT           

    
   GOTO Start

     
KES:
    IF ZeroLine THEN CountVal=CountVal + 1  ' Catch zero cross point.
@ INT_RETURN
                
        
END