NeoPixel Digital RGB LED Brightest / Fade

[anakinjay]

Just got my led strip (http://adafruit.com/products/1138) , and love it... hooked everything up to my arduino mega using the library at https://github.com/adafruit/Adafruit_NeoPixel

I can't figure out how to fade the brightness of leds though, only changing the color at full brightness.

I'd like to create a fading effect where the led fades to off, then slowly fades to full brightness, then back.... Can anyone help me out with this? Thanks in advance!!

[adafruit_support_bill]

To fade, just decrease the value of the R, G and B values. For example: This should fade pixel 0 from white to black.

Code: Select all

  for (int i = 255; i > 0; i--)
  {
      strip.setPixelColor(0, color(i,i,i));
      strip.show();
      delay(10);
  }

[Capeman]

Hi there, how can i make the strip fade from one color into another?

I know there is the color wheel, but i cant figure out how to set it up to just fade from red to blue!

Andy

[adafruit_support_bill]

This is the formula. There is room for optimization if you are looking for performance.

Code: Select all

for(int i = 0; i < n; i++) // larger values of 'n' will give a smoother/slower transition.
{
   Rnew = Rstart + (Rend - Rstart) * i / n;
   Gnew = Gstart + (Gend - Gstart) * i / n;
   Bnew = Bstart + (Bend - Bstart) * i / n;
// set pixel color here
}

[Snakin]

Hi folks. The initial example above makes sense in of itself, but I am a completely new Arduino user, so please tell me what goes around the code. I can't seem to paste it into any of the example sketches without getting a compile error. Much appreciated!.'.

[adafruit_support_bill]

If you download the neopixel library: https://github.com/adafruit/Adafruit_NeoPixel
and open one of the examples, it will have all the basic code structure you need. What is inside the "loop()" function is what you can modify to alter the patterns. To run the example above, just clean out everything in the loop function and drop it in:

Code: Select all

void loop()
{
  for (int i = 255; i > 0; i--)
  {
      strip.setPixelColor(0, color(i,i,i));
      strip.show();
      delay(10);
  }
}

[Snakin]

Thanks so much!.'.