Triggered fading

[imagineerdan]

How can I get the FC-4 to fade a lamp up, then waiting a few seconds, the fading down. By triggering a pin on the prop1?

[JonnyMac]

You didn't specify the fade up and down time so I used two seconds (8 milliseconds per step).  Note that you have to add the fade timing to your between-fades delay.  Please have a look at the FC-4 docs for complete details.

' =========================================================================
'
'   File...... Triggered_Fade.BS1
'   Purpose...
'   Author.... Jon Williams, EFX-TEK
'              Copyright (c) 2009 EFX-TEK
'              Some Rights Reserved
'              -- see http://creativecommons.org/licenses/by/3.0/
'   E-mail.... jwilliams@efx-tek.com
'   Started...
'   Updated... 14 APR 2009
'
'   {$STAMP BS1}
'   {$PBASIC 1.0}
'
' =========================================================================


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


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


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

SYMBOL  Sio             = 7                     ' SETUP = UP; no ULN
SYMBOL  Trigger         = PIN6                  ' SETUP = DN


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

SYMBOL  IsOn            = 1                     ' for active-high in/out
SYMBOL  IsOff           = 0

SYMBOL  Yes             = 1
SYMBOL  No              = 0


SYMBOL  Baud            = OT2400                ' B/R jumper removed


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

SYMBOL  timer           = B2


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

Reset:
  PINS = %00000000                              ' clear all
  DIRS = %00000000                              '


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

Main:
  timer = 0                                     ' reset timer

Check_Trigger:
  PAUSE 5                                       ' loop pad
  timer = timer + 5 * Trigger                   ' update timer
  IF timer < 100 THEN Check_Trigger             ' wait for 0.1 sec input

Fade_Up:
  SEROUT Sio, Baud, ("!FC4", %00, "F", 1, 0, 255, 8)

Delay:
  PAUSE 5000                                    ' ~2 (fade) + 3

Fade_Down:
  SEROUT Sio, Baud, ("!FC4", %00, "F", 1, 255, 0, 8)

  GOTO Main


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


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


' -----[ User Data ]-------------------------------------------------------

[imagineerdan]

wonderful that works great! How can I add in a corss fade function. The same functionality as the other code but cross fading between 2 lights?

[JonnyMac]

When you review the FC-4 docs (hint, hint...) this will make perfect sense.

' =========================================================================
'
'   File...... Triggered_Fade.BS1
'   Purpose...
'   Author.... Jon Williams, EFX-TEK
'              Copyright (c) 2009 EFX-TEK
'              Some Rights Reserved
'              -- see http://creativecommons.org/licenses/by/3.0/
'   E-mail.... jwilliams@efx-tek.com
'   Started...
'   Updated... 14 APR 2009
'
'   {$STAMP BS1}
'   {$PBASIC 1.0}
'
' =========================================================================


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


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


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

SYMBOL  Sio             = 7                     ' SETUP = UP; no ULN
SYMBOL  Trigger         = PIN6                  ' SETUP = DN


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

SYMBOL  IsOn            = 1                     ' for active-high in/out
SYMBOL  IsOff           = 0

SYMBOL  Yes             = 1
SYMBOL  No              = 0


SYMBOL  Baud            = OT2400                ' B/R jumper removed


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

SYMBOL  timer           = B2


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

Reset:
  PINS = %00000000                              ' clear all
  DIRS = %00000000                              '


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

Main:
  SEROUT Sio, Baud, ("!FC4", %00, "D", %0001)   ' Ch1 on
  timer = 0                                     ' reset timer

Check_Trigger:
  PAUSE 5                                       ' loop pad
  timer = timer + 5 * Trigger                   ' update timer
  IF timer < 100 THEN Check_Trigger             ' wait for 0.1 sec input

Fade_1_to_2:
  SEROUT Sio, Baud, ("!FC4", %00, "C", 0, 1, 2, 8)

Delay:
  PAUSE 5000                                    ' ~2 (fade) + 3

Fade_2_to_1:
  SEROUT Sio, Baud, ("!FC4", %00, "C", 0, 2, 1, 8)

  GOTO Main


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


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


' -----[ User Data ]-------------------------------------------------------

[imagineerdan]

Thanks Jon this did help in combination with the documentation. I still cant figure out how to adjust fade speed?

[JonnyMac]

The fade speed is based on the number of steps (usually 256) and the time delay per step.  For a full fade, from 0 to 255  or 255 to 0 (256 steps) and a step delay of 8 milliseconds your fade timing is 256 x 8 = 2048 (just a hair over 2 seconds).  If you wanted to lengthen the fade to 3 seconds you would set the step delay to 12.

To calculate the step delay do this:
a) take fade (in milliseconds) and
b) divide by the number of steps in the fade (256 for full off-to-on or on-to-off)
c) round result to the nearest whole number

For example:

  3000ms / 256 steps = 11.72 ms/step which would be rounded to 12

There are options with the C command that allow you to do partial fades so if you use those you'll have to adjust accordingly.

[imagineerdan]

How would a fade on 4 seconds look in the serial command?

[JonnyMac]

This command will fade channel 1 from off (0) to full on (255) in about 4 seconds:

  SEROUT Sio, Baud, ("!FC4", %00, "F", 1, 0, 255, 16)

The fade step timing is calculated like this:

4000ms (4 seconds) / 256 (steps) = 15.62 --> round up to 16; actual fade time is 4.096 seconds.

Note: If you look at the examples in this thread you'll see that there for each second of a full fade you'll have four units in the step size, so 1 sec = 4, 2 secs = 8, 3 secs = 12, 4 secs = 16, etc.