How can I create a smooth color fader animation with FastLED functions? Hello,

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1

How can I create a smooth color fader animation with FastLED functions?

Hello, I want to create a simple color fader that just moves through each color via the HSV color system. Currently I am doing it this way:

loop() {
fill_solid(leds, NUM_LEDS, CHSV(hue++,255,255));
delay(…);
}

But it makes the animation look choppy at slower speeds (with a delay). I would expect the occuring colors to be something like the following:

rgb(255, 0, 0)
rgb(255, 1, 0)
rgb(255, 2, 0)
rgb(255, 3, 0)
…

but instead they are more like this (I didn’t test the exact values but the increments are much bigger like you can see):

rgb(255, 0, 0)
rgb(255, 4, 0)
rgb(255, 8, 0)
rgb(255, 12, 0)
…

Obviously the first method would give me a much smoother animation while I would have to adjust the speed.

Is there a FastLED function that I can use to replicate the upper behaviour without coding it myself? If not, what would be the easiest way to do it?

Thank you!

2

If you’re just modifying the hue part of the HSV color space, then that necessarily will be gappy, since it’s a single 8-bit number (hue) mapping to a 24-bit number (RGB).

To get what you want with FastLED, you can use the triwave8() function perhaps:

uint8_t i;
loop() {
uint8_t v = triwave8(i++);
fill_solid( leds, NUM_LEDS, CRGB( v, 85-v, 171-v);
delay(…);
}

The triwave8() func is described here: https://github.com/FastLED/FastLED/wiki/FastLED-Wave-Functions and my intent in code above is to fake the FastLED “spectrum” color cycle here: https://github.com/FastLED/FastLED/wiki/FastLED-HSV-Colors