How to get neopixel to fade colorwipe?

Question

I'm trying to get a fade to happen when an LED turns on/off during the color wipe rather than just abruptly turning on/off. I'm not quite sure how to do this though.

#include <Adafruit_NeoPixel.h>

Adafruit_NeoPixel strip = Adafruit_NeoPixel(8, 3, NEO_RGBW + NEO_KHZ800);
void setup() {
  strip.begin();
}

void loop() {
  colorWipe(strip.Color(255, 255, 255), 150); // Red
 colorWipe(strip.Color(0, 0, 0), 150); // Red
 delay(5000);
}

void colorWipe(uint32_t color, uint8_t wait) {
  for(uint16_t i=0; i<strip.numPixels(); i++) {
      strip.setPixelColor(i, color);
      strip.show();
      delay(1000);
  }
}

This works! Just had to uncomment the delay within the while — Soumitras, Oct 31 '18 at 15:46

score 3 · Answer 1 · edited Feb 23 '18 at 09:36

You could change the intensity of each colour in steps till you get to your target colour.

void colorFade(uint8_t r, uint8_t g, uint8_t b, uint8_t wait) {
  for(uint16_t i = 0; i < strip.numPixels(); i++) {
      uint8_t curr_r, curr_g, curr_b;
      uint32_t curr_col = strip.getPixelColor(i); // get the current colour
      curr_b = curr_col & 0xFF; curr_g = (curr_col >> 8) & 0xFF; curr_r = (curr_col >> 16) & 0xFF;  // separate into RGB components

      while ((curr_r != r) || (curr_g != g) || (curr_b != b)){  // while the curr color is not yet the target color
        if (curr_r < r) curr_r++; else if (curr_r > r) curr_r--;  // increment or decrement the old color values
        if (curr_g < g) curr_g++; else if (curr_g > g) curr_g--;
        if (curr_b < b) curr_b++; else if (curr_b > b) curr_b--;
        strip.setPixelColor(i, curr_r, curr_g, curr_b);  // set the color
        strip.show();
        // delay(wait);  // add a delay if its too fast
      }
      delay(1000);
  }
}

To use it:

void loop() {
  colorFade(255, 0, 0, 150); // fade into red
  colorFade(255, 255, 255, 150); // and then into white
  delay(5000);
}

This is untested, so I dont know if it will be too fast or too slow. You'll have to tweak it to your needs.

How to get neopixel to fade colorwipe?

1 Answers1