Can you store RGB values in variable for neopixels?

Projects Programming
10

Use the source, luke!

Let's look at the adafruit library... when you call setPixelColor() with two arguments, that can only be calling this:

void Adafruit_NeoPixel::setPixelColor(uint16_t n, uint32_t c) {
  if(n < numLEDs) {
    uint8_t *p,
      r = (uint8_t)(c >> 16),
      g = (uint8_t)(c >>  8),
      b = (uint8_t)c;
    if(brightness) { // See notes in setBrightness()
      r = (r * brightness) >> 8;
      g = (g * brightness) >> 8;
      b = (b * brightness) >> 8;
    }
    if(wOffset == rOffset) {
      p = &pixels[n * 3];
    } else {
      p = &pixels[n * 4];
      uint8_t w = (uint8_t)(c >> 24);
      p[wOffset] = brightness ? ((w * brightness) >> 8) : w;
    }
    p[rOffset] = r;
    p[gOffset] = g;
    p[bOffset] = b;
  }
}

And you see, the "colors" that you're passing it are just an unsigned long (uint32). The color function returns a uint32:

uint32_t Adafruit_NeoPixel::Color(uint8_t r, uint8_t g, uint8_t b) {
  return ((uint32_t)r << 16) | ((uint32_t)g <<  8) | b;
}

So there you go - you can store colors in uint32's (unsigned long) or generate packed colors on the fly.

OR, you can just use the version of setPixelColor that takes the three colors separately instead of one packed 32-bit value, eg, this one:

void Adafruit_NeoPixel::setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b)

I'm not even going to ask what a "nose jewel" is...