Arduino with WS2812 using Adafruit NeoPixel library fade in/out different patterns

Question

Hey all I have been trying to figure out a way to random set patterns for my fade in/ out code below:

int PIN = 3;
int totalLEDs = 11;
int ledFadeTime = 5;
Adafruit_NeoPixel strip = Adafruit_NeoPixel(totalLEDs, PIN, NEO_GRB + NEO_KHZ800);
void setup() {
 strip.begin();
 strip.show(); // Initialize all pixels to 'off'
}
void loop() {
 rgbFadeInAndOut(0, 0, 255, ledFadeTime); // Blue
}
void rgbFadeInAndOut(uint8_t red, uint8_t green, uint8_t blue, uint8_t wait) {
 for(uint8_t b = 0; b <255; b++) {
 for(uint8_t i=0; i < strip.numPixels(); i++) {
 strip.setPixelColor(i, red * b/255, green * b/255, blue * b/255);
 }
 strip.show();
 delay(wait);
 };
 for(uint8_t b=255; b > 0; b--) {
 for(uint8_t i = 0; i < strip.numPixels(); i++) {
 strip.setPixelColor(i, red * b/255, green * b/255, blue * b/255);
 }
 strip.show();
 delay(wait);
 };
};

The code above works great. Fades the blue in and out infinity times. However, I am wanting random LEDs to be off or have a lighter/darker shade of the color I choose (in the above it's blue).

Example:

[off][blue][blue][off][off][dark blue][blue][off][dark blue][dark blue][off]
[blue][blue][blue][dark blue][off][blue][dark blue][blue][dark blue][off][off]
etc etc...

Would anyone happen to have code already like this?

Any help would be great! Thanks!

Answer 1

To make randomly-changing colours for the whole strip, change:

void loop() {
 rgbFadeInAndOut(0, 0, 255, ledFadeTime); // Blue
}

to:

void loop() {
 rgbFadeInAndOut(random (256), 
 random (256), 
 random (256), ledFadeTime); // random colour
}

---

If you want to make individual pixels different colours you could set up an array of colours, randomly initialize it, and use that. Like this:

#include <Adafruit_NeoPixel.h>
int PIN = 3;
int totalLEDs = 11;
int ledFadeTime = 5;
Adafruit_NeoPixel strip = Adafruit_NeoPixel(totalLEDs, PIN, NEO_GRB + NEO_KHZ800);
void setup() {
 strip.begin();
 strip.show(); // Initialize all pixels to 'off'
}
void loop() {
 rgbFadeInAndOut(ledFadeTime);
}
void rgbFadeInAndOut(uint8_t wait) {
 uint8_t red [totalLEDs];
 uint8_t green [totalLEDs];
 uint8_t blue [totalLEDs];
 // randomly set each colour
 for (int i = 0; i < totalLEDs; i++)
 {
 red [i] = random(256);
 green [i] = random(256);
 blue [i] = random(256);
 }
 for(uint8_t b = 0; b <255; b++) {
 for(uint8_t i=0; i < strip.numPixels(); i++) {
 strip.setPixelColor(i, red [i] * b/255, green [i] * b/255, blue [i] * b/255);
 }
 strip.show();
 delay(wait);
 }
 for(uint8_t b=255; b > 0; b--) {
 for(uint8_t i = 0; i < strip.numPixels(); i++) {
 strip.setPixelColor(i, red [i] * b/255, green [i] * b/255, blue [i] * b/255);
 }
 strip.show();
 delay(wait);
 }
}