Does FastLED.h provides a function that can get the color value of a LED?Like

B_way_Ng · March 31, 2018, 6:22am

Does FastLED.h provides a function that can get the color value of a LED?Like this
LED[I]=CHSV(LED[0].getColor(),LED[0].getSaturation(),LED[0].getBrightness());
I can’t find it in the document of FastLED
Thanks!

marmil · March 31, 2018, 7:17am

Once you assign (either RGB or HSV) values to a pixel it gets stored in the CRGB array as RGB values. You can access that at any time. For example if you wanted the RGB data for leds[0] you could do something like this:
Serial.print("leds[0] RGB: “); Serial.print(leds[0].r); Serial.print(” “); Serial.print(leds[0].g); Serial.print(” "); Serial.println(leds[0].b);

Also, here’s an example if you want that data back as HSV, but converting it back from RGB isn’t away exact.

github.com

marmilicious/FastLED_examples/blob/master/RGB_2_HSV_2_RGB_convert.ino

//***************************************************************
//  Demo of converting HSV to RGB_rainbow values.
//  And then converting RGB back to HSV to show how close it is.
//
//  Values are printed to serial monitor.
//
//  The first two pixels will show that the HSV to RGB converted
//  colors always match.  Observing the third pixel will show
//  how the conversion from RGB back to HSV is often pretty
//  close, but can be a bit off sometimes. Converting RGB to HSV
//  works best with fully saturated colors.
//
//  Marc Miller, Nov 2017
//***************************************************************

#include "FastLED.h"
#define DATA_PIN    11
#define CLOCK_PIN   13
#define LED_TYPE    LPD8806
#define COLOR_ORDER GBR

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Andrew_Tuline · March 31, 2018, 7:32pm

Thanks for that example Marc. I was working with a local artist and he wanted waves of just soft white. The only problem is that as you get to very low intensity, the colour skews signficantly. I’m ordering up some soft white SK6812’s to play with.

marmil · April 2, 2018, 3:08am

@Andrew_Tuline I think you’re on the right track if the artist only wants white.