Example Code for Arduino-Flowing Water Lighting Effect 2

Last revision 2026/01/15

This example demonstrates another flowing water lighting effect using the WS2812B Ring Lamp with Arduino. Users can learn how to control WS2812B LEDs using the Adafruit_NeoPixel library.

Hardware Preparation

Software Preparation

Wiring Diagram

Connection Diagram

Sample Code

#include <Adafruit_NeoPixel.h>    //needed for the WS2812
#include <avr/pgmspace.h>         //needed for PROGMEM

#define PIN 6                    //Pin 1 is DATA In on the bottom Ring
#define BRIGHTNESS 93            // brightness reduced



//Lookup for the Candle light
const unsigned int candles[] PROGMEM =
{
  15, 10, 48, 45, 36, 19, 59, 29, 5, 43, 41, 39, 24, 3, 61
};

Adafruit_NeoPixel strip = Adafruit_NeoPixel(93, PIN, NEO_GRB + NEO_KHZ800);

// IMPORTANT: To reduce NeoPixel burnout risk, add 1000 uF capacitor across
// pixel power leads, add 300 - 500 Ohm resistor on first pixel's data input
// and minimize distance between Arduino and first pixel.  Avoid connecting
// on a live circuit...if you must, connect GND first.

void setup() {
  pinMode(PIN, OUTPUT);
  strip.begin();
  strip.setBrightness(BRIGHTNESS); // set brightness
  strip.show(); // Initialize all pixels to 'off'
}

void loop() {
  tree();
  delay(1000);

  colorcrazy();

  theaterChaseRainbow(50);

  comet();

  warpdrive();
  warpdrive();

  rainbowCycle(1);

  rainbow(5);
  rainbow(5);
  rainbow(5);


  colorWipe(strip.Color(255, 0, 0), 50); // Red
  colorWipe(strip.Color(0, 255, 0), 50); // Green
  colorWipe(strip.Color(0, 0, 255), 50); // Blue

  //
  //
  //  cometr();
  //Tree light:

  //
  //  warpdrive();
  //
  //
  //  comet();


  /*
    // Some example procedures showing how to display to the pixels:
    colorWipe(strip.Color(255, 0, 0), 50); // Red
    colorWipe(strip.Color(0, 255, 0), 50); // Green
    colorWipe(strip.Color(0, 0, 255), 50); // Blue
    // Send a theater pixel chase in...
    theaterChase(strip.Color(127, 127, 127), 50); // White
    theaterChase(strip.Color(127,   0,   0), 50); // Red
    theaterChase(strip.Color(  0,   0, 127), 50); // Blue
    rainbow(20);
    rainbowCycle(20);
    theaterChaseRainbow(50);
  */
}

//Sub-----------------------------------------------------------------------

//Comet
void comet() {
  for (uint16_t i = strip.numPixels(); i > 0; i--) {
    strip.setPixelColor(i, strip.Color(0, 0, 255));
    fadethemall(10);
    fadethemall(10);
  }
}

void cometr() {
  for (uint16_t i = strip.numPixels(); i > 0; i--) {
    strip.setPixelColor(i, strip.Color(255, 0, 0));
    fadethemall(10);
    fadethemall(10);
  }
}


//From top down white pulses
void warpdrive() {

  //Top Led
  strip.setPixelColor(60, strip.Color(255, 255, 255));
  strip.show();
  //fade a bit
  for (int i = 0; i < 20; i++)
  {
    fadethemall(20);
  }
  //8 Ring
  for (int i = 52; i < 60; i++)
  {
    strip.setPixelColor(i, strip.Color(255, 255, 255));
  }
  strip.show();
  //fade a bit
  for (int i = 0; i < 20; i++)
  {
    fadethemall(20);
  }
  //12 Ring
  for (int i = 40; i < 52; i++)
  {
    strip.setPixelColor(i, strip.Color(255, 255, 255));
  }
  strip.show();
  //fade a bit
  for (int i = 0; i < 20; i++)
  {
    fadethemall(20);
  }
  //16 Ring
  for (int i = 24; i < 40; i++)
  {
    strip.setPixelColor(i, strip.Color(255, 255, 255));
  }
  strip.show();
  //fade a bit
  for (int i = 0; i < 20; i++)
  {
    fadethemall(20);
  }
  //24 Ring
  for (int i = 0; i < 24; i++)
  {
    strip.setPixelColor(i, strip.Color(255, 255, 255));
  }
  strip.show();
  //fade a bit
  for (int i = 0; i < 20; i++)
  {
    fadethemall(20);
  }

  //Extra by John Kerr
  strip.setPixelColor(60, strip.Color(0, 0, 0));
  strip.show();
  //fade a bit
  for (int i = 0; i < 20; i++)
  {
    fadethemall(20);
  }

}

//This reduces the brightness of all leds
void fadethemall(uint8_t wait) {
  for (uint16_t i = 0; i < strip.numPixels(); i++) {
    uint32_t color = strip.getPixelColor(i);
    int r;
    int g;
    int b;
    r = (uint8_t)(color >> 16);
    g = (uint8_t)(color >>  8);
    b = (uint8_t)color;

    if (r > 0)
    {
      r = r - 1;
    }
    else
    {
      r = 0;
    }

    if (g > 0)
    {
      g = g - 1;
    }
    else
    {
      g = 0;
    }

    if (b > 0)
    {
      b = b - 1;
    }
    else
    {
      b = 0;
    }

    strip.setPixelColor(i, strip.Color(r, g, b));
  }
  strip.show();
  delay(wait);
}

//This drives the WS2812 in a crazy pattern, fun!
void colorcrazy() {
  colorWipe(strip.Color(255, 0, 0), 25); // Red
  colorWipe(strip.Color(0, 255, 0), 25); // Green
  colorWipe(strip.Color(0, 0, 255), 25); // Blue
  theaterChaseRainbow(5);
}

//This lights up the tree in green, then add the white "candles"
void tree() {

  colorWipe(strip.Color(0, 50, 0), 50); // Green

  //light "candles"
  //Show the S:
  for (int i = 0; i < 16; i++)
  {
    strip.setPixelColor(pgm_read_word(&candles[i]) - 1, strip.Color(255, 255, 255));
    strip.show();
    delay(50);
  }
}

// Fill the dots one after the other with a color
void colorWipe(uint32_t c, uint8_t wait) {
  for (uint16_t i = 0; i < strip.numPixels(); i++) {
    strip.setPixelColor(i, c);
    strip.show();
    delay(wait);
  }
}

void rainbow(uint8_t wait) {
  uint16_t i, j;

  for (j = 0; j < 256; j++) {
    for (i = 0; i < strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel((i + j) & 255));
    }
    strip.show();
    delay(wait);
  }
}

// Slightly different, this makes the rainbow equally distributed throughout
void rainbowCycle(uint8_t wait) {
  uint16_t i, j;

  for (j = 0; j < 256 * 5; j++) { // 5 cycles of all colors on wheel
    for (i = 0; i < strip.numPixels(); i++) {
      strip.setPixelColor(i, Wheel(((i * 256 / strip.numPixels()) + j) & 255));
    }
    strip.show();
    delay(wait);
  }
}

//Theatre-style crawling lights.
void theaterChase(uint32_t c, uint8_t wait) {
  for (int j = 0; j < 10; j++) { //do 10 cycles of chasing
    for (int q = 0; q < 3; q++) {
      for (int i = 0; i < strip.numPixels(); i = i + 3) {
        strip.setPixelColor(i + q, c);  //turn every third pixel on
      }
      strip.show();

      delay(wait);

      for (int i = 0; i < strip.numPixels(); i = i + 3) {
        strip.setPixelColor(i + q, 0);      //turn every third pixel off
      }
    }
  }
}

//Theatre-style crawling lights with rainbow effect
void theaterChaseRainbow(uint8_t wait) {
  for (int j = 0; j < 256; j++) {   // cycle all 256 colors in the wheel
    for (int q = 0; q < 3; q++) {
      for (int i = 0; i < strip.numPixels(); i = i + 3) {
        strip.setPixelColor(i + q, Wheel( (i + j) % 255)); //turn every third pixel on
      }
      strip.show();

      delay(wait);

      for (int i = 0; i < strip.numPixels(); i = i + 3) {
        strip.setPixelColor(i + q, 0);      //turn every third pixel off
      }
    }
  }
}

// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t Wheel(byte WheelPos) {
  WheelPos = 255 - WheelPos;
  if (WheelPos < 85) {
    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
  } else if (WheelPos < 170) {
    WheelPos -= 85;
    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
  } else {
    WheelPos -= 170;
    return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
  }
}

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