' =========================================================================
'
'   File....... SW21-EX02-Flash_LED-Cntr.BS2
'   Purpose.... Advanced LED Flasher
'   Author..... (C) 2000 - 2005, Parallax, Inc.
'   E-mail..... support@parallax.com
'   Started....
'   Updated.... 01 SEP 2005
'
'   {$STAMP BS2}
'   {$PBASIC 2.5}
'
' =========================================================================


' -----[ Program Description ]---------------------------------------------
'
' Flashes an LED connected to P0, controlled by the value of a bit that's
' part of another variable.  This program will work, unmodified, on
' any BS2-family module.


' -----[ I/O Definitions ]-------------------------------------------------

Strobe          PIN     0                       ' LED on P0


' -----[ Constants ]-------------------------------------------------------

IsOn            CON     1                       ' on for active-high LED
IsOff           CON     0                       ' off for active-high LED


' -----[ Variables ]-------------------------------------------------------

cntr            VAR     Nib                     ' simple counter, 0 - 15


' -----[ Initialization ]--------------------------------------------------

Reset:
  Strobe = IsOff
  OUTPUT Strobe                                 ' enable pin to drive LED


' -----[ Program Code ]----------------------------------------------------

Main:
  DO
    Strobe = cntr.BIT0
    PAUSE 500
    cntr = cntr + 1
  LOOP