How to use the hsv2rgb conversion?

Robin_Gerritsen · February 10, 2018, 2:45pm

How to use the hsv2rgb conversion?
I am currently using leds[cursor] = 0xff0000 to define the color of the leds-strip. But when I want to scroll through the hue rainbow I would like to make use of the hsv2rgb conversion.

How do I get the desired output like 0xff0000 while using hsv2rgb?
I now use a long to save the rgb inside:

long defColor;
byte defRed = 255;
byte defGreen = 0;
byte defBlue = 0;

defColor = ((long)defRed << 16L) | ((long)defGreen << 8L) | (long)defBlue;

leds[cursor] = defColor;

marmil · February 10, 2018, 3:07pm

Here’s an example:

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

This file has been truncated. show original

Read more here:
https://github.com/FastLED/FastLED/blob/master/hsv2rgb.h#L52

Robin_Gerritsen · February 10, 2018, 3:34pm

@marmil Thanks, managed to get it work:
hue++;
CHSV hsv(hue,255,255);
CRGB rgb;
hsv2rgb_rainbow(hsv, rgb);
curColor = ((long)rgb.r << 16L) | ((long)rgb.g << 8L) | (long)rgb.b;