' =========================================================================
'
'   File....... Spooky_Eyes.BS1
'   Purpose.... Random "eyes" controller for Halloween haunts
'   Author..... Jon Williams -- Parallax, Inc.
'   E-mail..... jwilliams@parallax.com
'   Started....
'   Updated.... 16 JAN 2005
'
'   {$STAMP BS1}
'   {$PBASIC 1.0}
'
' =========================================================================


' -----[ Program Description ]---------------------------------------------
'
' While triggered, this program will randomly select an set of "eyes" and
' bring them on gradually, hold them on for a moment, then extinguish
' them.  The process will complete as long as the trigger is present.


' -----[ Revision History ]------------------------------------------------

' 15 JAN 2005 - First version; tested on Parallax BS1 Project Board


' -----[ I/O Definitions ]-------------------------------------------------

SYMBOL  Trigger         = PIN7


' -----[ Constants ]-------------------------------------------------------

SYMBOL  IsOn            = 0                     ' active low input
SYMBOL  IsOff           = 1

SYMBOL  EyePorts        = 7                     ' # eye control pins


' -----[ Variables ]-------------------------------------------------------

SYMBOL  randVal         = W1                    ' for random # generator
SYMBOL  eyeNum          = B4                    ' selected eye pin
SYMBOL  lastNum         = B5                    ' last eye on
SYMBOL  level           = B6                    ' brighness level


' -----[ Initialization ]--------------------------------------------------

Reset:
  lastNum = EyePorts - 1                        ' calc last control pin
  FOR eyeNum = 0 TO lastNum                     ' set used control pins
    LOW eyeNum                                  ' make output and off
  NEXT


' -----[ Program Code ]----------------------------------------------------

Main:
  RANDOM randVal                                ' tumble random generator
  IF Trigger = IsOff THEN Main                  ' wait for trigger

Get_Eye:
  eyeNum = randVal // EyePorts                  ' make 0 to (EyePorts - 1)
  IF eyeNum = lastNum THEN Main                 ' do not allow repeat
  lastNum = eyeNum                              ' save current selection

Show_Eye:
  FOR level = 0 TO 255 STEP 5                   ' increase brightness
    PWM eyeNum, level, 3                        ' modulate LED eyes
  NEXT
  HIGH eyeNum                                   ' full bright
  PAUSE 500                                     ' leave on for a bit
  LOW eyeNum                                    ' selected eye off
  PAUSE 100                                     ' inter-eye delay
  GOTO Main                                     ' start again 