Help with Comparator and Timer0

[dbachman]

I have been trying to write some code around the GIF that Darrel Taylor showed me but with mixed results. I have included the GIF and the code. Can someone take a look at it to see if what I am doing is a start? I am just using the LED to see if anything is working. It flashes but not when I expect it should

Thanks Don

(From Darrel Taylor)
I'll second the Comparator idea, but with a little difference. (Don't filter the signal)

Set a timer to have a delay of 20ms or more.
Using the comparator Interrupts, reload that timer every time you get a pulse.

If the voltage drops below the comparator's trigger point, the timer will overflow.
Use the timer interrupt/flag to determine when there's an error condition

Here is what I have for code:

OSCCON = $60      'Set up oscillator 4mhz
CMCON = %11000001
TRISB = %00000000 'Set port B to output
TRISA = $%11111111 'Set port A to input
T0CON = %01000110 'Set up Timer 0 Config bits prescale 128
INTCON.7 = 1 'Enable all unmasked interrupts
INTCON.6 = 1 'Enable all unmasked peripheral interrupts
RCON.7 = 0 'Disable interrupt priority
Intcon.5 = 1 'Timer 0 overflow interrupt enable bit
PIE2.6 = 1 'Comparator interrupt enable bit

Main:
      
While Pir2.6 = 0 or Intcon.2 = 0 'Check to see if comparator interrupt bit or Timer0 interrupt bit is set
wend   
      if TMR0IF = 1 then gosub LED
      TMR0L = $64 'Preload Timer 0 
      Pir2.6 = 0  'Clear comparator interrupt bit
      goto main
      
      
LED:

      High portb.4
      pause 100
      low portb.4
      pause 100
      goto LED
      
End