'=======================================================
'Demonstrate a simple Software Frequency Counter
'  Uses timer0 as a 1 second timer
'=======================================================
func main()
 dim fcount

again:
  fcount = countpulses()
  print fcount,"Hz"
  goto again

endfunc


'======================================================
'Count the cycles
'======================================================
func countpulses()

    dim fcount
    clear fcount

    '----------------------------------------------------
    'First thing setup timer 0
    '----------------------------------------------------
    INTCON.bit(2)=0 'clear timer0 overflow flag
    T0CON.bit(7)=0 'Make sure its off
    TMR0H=103  '1 second (you must always write high byte first
    TMR0L=150
    T0CON.bit(6)=0 '16 bit mode
    T0CON.bit(5)=0 'Internal clock
    T0CON.bit(3)=0 'Assign prescale
    T0CON.bit(2)=1 'Prescale  Each Tic = 25.6us
    T0CON.bit(1)=1 'Prescale
    T0CON.bit(0)=1 'Prescale

    T0CON.bit(7)=1 'Start Timer

loop1:
    if INTCON.bit(2) = 1 then exit fcount
    if IOPORT(15) = 0 then goto loop1

loop2:
    if INTCON.bit(2) = 1 then  exit fcount
    if IOPORT(15) = 1 then goto loop2

    inc fcount
    goto loop1

endfunc