Glowing Coals Gag

[clinefx1]

I'm working on a fire place gag and having some issues. I've taken a few WickLED units and swapped some of the LEDs out for red ones. Then glued the units inside chucks of clear silicone and dressed them in with wood ash.  I'm having trouble slowing the flicker rate down on the WickLED program to the get the right look. I guess I'm looking for more of a slow throb than a flicker. Got any ideas?


Thanks
Chris

[JonnyMac]

The capacitor in the WickLED circuit is optimized for the candle flicker rate.  I know of one prop builder -- an experienced electronics engineer -- who replaced the caps with much larger ones so that he could get a very slow decay (like you, he was using the device for a different effect).  It may be easier to build your own circuit; use the schematic below as a guide.



If you can't find big caps then you can add more to the circuit -- remember, you must add caps in parallel to increase the capacitance.

[clinefx1]

Thanks. I think the units look good with the caps that came with.  I guess I was fishing for program help.

-Chris

[JonnyMac]

Sorry, Chis, I misunderstood.  Give this a try; you can adjust the flickering behavior by modifying the GLOW_MIN and GLOW_MAX constants.

' =========================================================================
'
'   File...... Coals.BS1
'   Purpose...
'   Author.... Jon Williams, EFX-TEK
'   E-mail.... jwilliams@efx-tek.com
'   Started...
'   Updated... 30 JUL 2007
'
'   {$STAMP BS1}
'   {$PBASIC 1.0}
'
' =========================================================================


' -----[ Program Description ]---------------------------------------------


' -----[ Revision History ]------------------------------------------------


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


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

SYMBOL  GLOW_MIN        = 50
SYMBOL  GLOW_MAX        = 150


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

SYMBOL  idx             = B2
SYMBOL  delay           = B3
SYMBOL  lottery         = W5                    ' random value


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

Reset:
  DIRS = %00111111                              ' set outputs


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

Main:
  FOR idx = 1 TO 3
     RANDOM lottery                             ' stir random value
  NEXT
  PINS = lottery                                ' light the coals
  delay = GLOW_MAX - GLOW_MIN + 1               ' span
  delay = lottery // delay + GLOW_MIN           ' calcualte delay
  PAUSE delay
  GOTO Main


' -----[ Subroutines ]-----------------------------------------------------


' -------------------------------------------------------------------------


' -----[ EEPROM Data ]-----------------------------------------------------

[clinefx1]

Thanks for all the help today.

Chris