1. Home
  2. Embedded Programming
  3. Flicker algorithm help

Flicker algorithm help

I am just starting a small design for amateur theatre group. They want me to build a camp-fire simulator.

I already have a home-built control box and slave units for switching practicals. The control box contains a ATmega32 and each of the slaves contains an Atmega8 with an opto-isolated solid state relay. They use a multi-drop RS 485 comms network so that any number of slaves can be connected to one master.

Does anyone out there have a good algorithm to simulate the flickering of a camp-fire, or will a simple pseudo-random sequence be sufficient?

--
John B
Reply to
John B
Loading thread data ...

to build a camp-fire

practicals. The control box

opto-isolated solid state

slaves can be connected to

a camp-fire, or will a

Circuit Cellar had a project 2 or 3 years ago IIRC for handheld candles on stage. I don't have a link but the article did talk about how to make the flicker convincing. You would probably want the same algorithm for a camp fire.

Bob

Reply to
Bob

On 18/01/2006 the venerable Bob etched in runes:

Thanks Bob. I'll have a look at their archive.

--
John B
Reply to
John B

... snip ...

Dunno, but I believe the old fashioned method was to have a small motor rotate a crumpled mica tube over a light bulb. Used in artificial fireplaces and the ilk.

--
"If you want to post a followup via groups.google.com, don't use
  the broken "Reply" link at the bottom of the article.  Click on
  "show options" at the top of the article, then click on the
  "Reply" at the bottom of the article headers." - Keith Thompson
More details at:
Reply to
Chuck F.

me

of

of

on

the

camp

this might help, too:

formatting link

several versions of a candle. One is the CC piece I was thinking of (Oct

2002). Bob
Reply to
Bob

I've seen modern implementations that use a shredded nylon cloth, blown upwards by a small fan, lit from beneath by a small colored lightbulb. Surprisingly effective.

Regards, -=Dave

--
Change is inevitable, progress is not.
Reply to
Dave Hansen

On 18/01/2006 the venerable Bob etched in runes:

. .

Hi Bob. I couldn't find the article on Circuit Cellar but I have just subscribed to the electronic edition!! That website is just what I need. Thanks.

--
John B
Reply to
John B

Nuts & Volts had a project on this for last October's issue. The article itself isn't online but there is a link to the example source code. Back issues are for sale, though, natch.

formatting link 

--
Rich Webb   Norfolk, VA
Reply to
Rich Webb

On 19/01/2006 the venerable Rich Webb etched in runes:

. . .

Thanks Rich. I've got the code, but haven't looked at it yet. I suppose I'll have to translate from BASIC to C. Hmmm, could be worse ;-)

--
John B
Reply to
John B

[...]

Here's an article with some info on simulating candle flicker.

formatting link

The basic answer is a pseudo-random sequence with a 1-pole low pass filter at some lowish frequency.

That URL's from my bookmarks, but I think I found it by looking through some of the same websites people are mentioning elsewhere in this thread :-)

--
   Wim Lewis , Seattle, WA, USA. PGP keyID 27F772C1
Reply to
Wim Lewis

On 22/01/2006 the venerable Wim Lewis etched in runes:

formatting link

Thanks Wim. That looks really useful. Code is in C too so conversion to AVR should be a breeze.

--
John B
Reply to
John B

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.