Help with WS2801 LED Strand -- Random Fade In & Out

hi guys,
it has been decades since i've touched code.  i'm working on project using arduino , ws2801 rgb led strand 20 pixels.

i want fade in , out (from off full white bright off) @ random population of led in strand of 20.

here's example of effect i'm trying accomplish. video . calls them splotches.



i can fade in , out led, i'm trying pseudo code random activation leds.

any ideas appreciated.

an explanation has happen + fastled code making happen can found here.

long story short: somewhere need store flag each led indicating if led brightening or diming @ moment.

depending on flag brighten or dim each led. if reach upper/lower limit (=led full on / off) inverse flag.

Arduino Forum > Using Arduino > LEDs and Multiplexing > Help with WS2801 LED Strand -- Random Fade In & Out

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